Split 'xo-reflectutil/' into commit '14cad16f1d'

git-subtree-dir: xo-reflectutil
git-subtree-mainline: b7a01660469ea5631d38f1e708919288d38c5662
git-subtree-split: 14cad16f1d

CMakeLists.txt

@@ -1,8 +1,10 @@
-# xo-expression2/CMakeLists.txt
+# xo-reader2/CMakeLists.txt
 
 cmake_minimum_required(VERSION 3.10)
 
-project(xo_expression2 VERSION 1.0)
+#set(CMAKE_CXX_STANDARD 23)
+
+project(xo_reader2 VERSION 1.0)
 enable_language(CXX)
 
 include(GNUInstallDirs)
@@ -22,310 +24,376 @@ add_definitions(${PROJECT_CXX_FLAGS})
 
 add_subdirectory(utest)
 
-# note: manual target; generated code committed to git
-xo_add_genfacet(
-    TARGET xo-expression2-facet-symboltable
-    FACET SymbolTable
-    INPUT idl/SymbolTable.json5
-    OUTPUT_HPP_DIR include/xo/expression2
-    OUTPUT_IMPL_SUBDIR detail
-    )
-
 # ----------------------------------------------------------------
 
 # note: manual target; generated code committed to git
 xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-symboltable-localsymtab
-    FACET_PKG xo_expression2
-#    REPR LocalSymtab
-    INPUT idl/ISymbolTable_DLocalSymtab.json5
-)
-
-# note: manual target; generated code committed to git
-xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-gcobject-localsymtab
+    TARGET xo-reader2-facetimpl-gcobject-schematikaparser
     FACET_PKG xo_alloc2
-#    REPR LocalSymtab
-    INPUT idl/IGCObject_DLocalSymtab.json5
-)
-
-# note: manual target; generated code committed to git
-xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-printable-localsymtab
-    FACET_PKG xo_printable2
-#    REPR LocalSymtab
-    INPUT idl/IPrintable_DLocalSymtab.json5
-)
-
-# ----------------------------------------------------------------
-
-# note: manual target; generated code committed to git
-xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-symboltable-globalsymtab
-    FACET_PKG xo_expression2
-#    REPR GlobalSymtab
-    INPUT idl/ISymbolTable_DGlobalSymtab.json5
-)
-
-# note: manual target; generated code committed to git
-xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-gcobject-globalsymtab
-    FACET_PKG xo_alloc2
-#    REPR GlobalSymtab
-    INPUT idl/IGCObject_DGlobalSymtab.json5
-)
-
-# note: manual target; generated code committed to git
-xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-printable-globalsymtab
-    FACET_PKG xo_printable2
-#    REPR GlobalSymtab
-    INPUT idl/IPrintable_DGlobalSymtab.json5
+    INPUT idl/IGCObject_DSchematikaParser.json5
 )
 
 # ----------------------------------------------------------------
 
 # note: manual target; generated code committed to git
 xo_add_genfacet(
-    TARGET xo-expression2-facet-expression
-    FACET Expression
-    INPUT idl/Expression.json5
-    OUTPUT_HPP_DIR include/xo/expression2
-    OUTPUT_IMPL_SUBDIR detail
+    TARGET xo-reader2-facet-syntaxstatemachine
+    FACET SyntaxStateMachine
+    INPUT idl/SyntaxStateMachine.json5
     )
 
 # ----------------------------------------------------------------
 
 # note: manual target; generated code committed to git
 xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-expression-constant
-    FACET_PKG xo_expression2
-#    REPR Constant
-    INPUT idl/IExpression_DConstant.json5
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-toplevelseqssm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DToplevelSeqSsm.json5
 )
 
 # note: manual target; generated code committed to git
 xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-gcobject-constant
-    FACET_PKG xo_alloc2
-#    REPR Constant
-    INPUT idl/IGCObject_DConstant.json5
-)
-
-# note: manual target; generated code committed to git
-xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-printable-constant
+    TARGET xo-reader2-facetimpl-printable-toplevelseqssm
     FACET_PKG xo_printable2
-#    REPR Constant
-    INPUT idl/IPrintable_DConstant.json5
+    INPUT idl/IPrintable_DToplevelSeqSsm.json5
 )
 
 # ----------------------------------------------------------------
 
 # note: manual target; generated code committed to git
 xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-expression-variable
-    FACET_PKG xo_expression2
-#    REPR Variable
-    INPUT idl/IExpression_DVariable.json5
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-definessm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DDefineSsm.json5
 )
 
 # note: manual target; generated code committed to git
 xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-gcobject-variable
-    FACET_PKG xo_alloc2
-#    REPR Variable
-    INPUT idl/IGCObject_DVariable.json5
-)
-
-# note: manual target; generated code committed to git
-xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-printable-variable
+    TARGET xo-reader2-facetimpl-printable-definessm
     FACET_PKG xo_printable2
-#    REPR Variable
-    INPUT idl/IPrintable_DVariable.json5
+    INPUT idl/IPrintable_DDefineSsm.json5
 )
 
 # ----------------------------------------------------------------
 
 # note: manual target; generated code committed to git
 xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-gcobject-typename
-    FACET_PKG xo_alloc2
-#    REPR Typename
-    INPUT idl/IGCObject_DTypename.json5
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-deftypessm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DDeftypeSsm.json5
 )
 
 # note: manual target; generated code committed to git
 xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-printable-typename
+    TARGET xo-reader2-facetimpl-printable-deftypessm
     FACET_PKG xo_printable2
-#    REPR Typename
-    INPUT idl/IPrintable_DTypename.json5
+    INPUT idl/IPrintable_DDeftypeSsm.json5
 )
 
 # ----------------------------------------------------------------
 
 # note: manual target; generated code committed to git
 xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-expression-varref
-    FACET_PKG xo_expression2
-#    REPR VarRef
-    INPUT idl/IExpression_DVarRef.json5
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-lambdassm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DLambdaSsm.json5
 )
 
 # note: manual target; generated code committed to git
 xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-gcobject-varref
-    FACET_PKG xo_alloc2
-#    REPR VarRef
-    INPUT idl/IGCObject_DVarRef.json5
-)
-
-# note: manual target; generated code committed to git
-xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-printable-varref
+    TARGET xo-reader2-facetimpl-printable-lambdassm
     FACET_PKG xo_printable2
-#    REPR VarRef
-    INPUT idl/IPrintable_DVarRef.json5
+    INPUT idl/IPrintable_DLambdaSsm.json5
 )
 
 # ----------------------------------------------------------------
 
 # note: manual target; generated code committed to git
 xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-expression-defineexpr
-    FACET_PKG xo_expression2
-#    REPR DefineExpr
-    INPUT idl/IExpression_DDefineExpr.json5
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-parenssm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DParenSsm.json5
 )
 
 # note: manual target; generated code committed to git
 xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-gcobject-defineexpr
-    FACET_PKG xo_alloc2
-#    REPR DefineExpr
-    INPUT idl/IGCObject_DDefineExpr.json5
-)
-
-# note: manual target; generated code committed to git
-xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-printable-defineexpr
+    TARGET xo-reader2-facetimpl-printable-parenssm
     FACET_PKG xo_printable2
-#    REPR DefineExpr
-    INPUT idl/IPrintable_DDefineExpr.json5
+    INPUT idl/IPrintable_DParenSsm.json5
 )
 
 # ----------------------------------------------------------------
 
 # note: manual target; generated code committed to git
 xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-expression-applyexpr
-    FACET_PKG xo_expression2
-#    REPR ApplyExpr
-    INPUT idl/IExpression_DApplyExpr.json5
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-expectformalarglistssm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DExpectFormalArglistSsm.json5
 )
 
 # note: manual target; generated code committed to git
 xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-gcobject-applyexpr
-    FACET_PKG xo_alloc2
-#    REPR ApplyExpr
-    INPUT idl/IGCObject_DApplyExpr.json5
-)
-
-# note: manual target; generated code committed to git
-xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-printable-applyexpr
+    TARGET xo-reader2-facetimpl-printable-expectformalarglistssm
     FACET_PKG xo_printable2
-#    REPR ApplyExpr
-    INPUT idl/IPrintable_DApplyExpr.json5
+    INPUT idl/IPrintable_DExpectFormalArglistSsm.json5
 )
 
 # ----------------------------------------------------------------
 
 # note: manual target; generated code committed to git
 xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-expression-lambdaexpr
-    FACET_PKG xo_expression2
-#    REPR LambdaExpr
-    INPUT idl/IExpression_DLambdaExpr.json5
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-expectformalargssm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DExpectFormalArgSsm.json5
 )
 
 # note: manual target; generated code committed to git
 xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-gcobject-lambdaexpr
-    FACET_PKG xo_alloc2
-#    REPR LambdaExpr
-    INPUT idl/IGCObject_DLambdaExpr.json5
-)
-
-# note: manual target; generated code committed to git
-xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-printable-lambdaexpr
+    TARGET xo-reader2-facetimpl-printable-expectformalargssm
     FACET_PKG xo_printable2
-#    REPR LambdaExpr
-    INPUT idl/IPrintable_DLambdaExpr.json5
+    INPUT idl/IPrintable_DExpectFormalArgSsm.json5
 )
 
 # ----------------------------------------------------------------
 
 # note: manual target; generated code committed to git
 xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-expression-ifelseexpr
-    FACET_PKG xo_expression2
-#    REPR IfElseExpr
-    INPUT idl/IExpression_DIfElseExpr.json5
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-ifelsessm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DIfElseSsm.json5
 )
 
 # note: manual target; generated code committed to git
 xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-gcobject-ifelseexpr
-    FACET_PKG xo_alloc2
-    INPUT idl/IGCObject_DIfElseExpr.json5
-)
-
-# note: manual target; generated code committed to git
-xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-printable-ifelseexpr
+    TARGET xo-reader2-facetimpl-printable-ifelsessm
     FACET_PKG xo_printable2
-    INPUT idl/IPrintable_DIfElseExpr.json5
+    INPUT idl/IPrintable_DIfElseSsm.json5
 )
 
 # ----------------------------------------------------------------
 
 # note: manual target; generated code committed to git
 xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-expression-sequenceexpr
-    FACET_PKG xo_expression2
-    INPUT idl/IExpression_DSequenceExpr.json5
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-sequencessm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DSequenceSsm.json5
 )
 
 # note: manual target; generated code committed to git
 xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-gcobject-sequenceexpr
-    FACET_PKG xo_alloc2
-    INPUT idl/IGCObject_DSequenceExpr.json5
-)
-
-# note: manual target; generated code committed to git
-xo_add_genfacetimpl(
-    TARGET xo-expression2-facetimpl-printable-sequenceexpr
+    TARGET xo-reader2-facetimpl-printable-sequencessm
     FACET_PKG xo_printable2
-    INPUT idl/IPrintable_DSequenceExpr.json5
+    INPUT idl/IPrintable_DSequenceSsm.json5
 )
 
 # ----------------------------------------------------------------
 
-xo_add_genfacet_all(xo-expression2-genfacet-all)
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-applyssm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DApplySsm.json5
+)
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-printable-applyssm
+    FACET_PKG xo_printable2
+    INPUT idl/IPrintable_DApplySsm.json5
+)
+
+# ----------------------------------------------------------------
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-expectsymbolssm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DExpectSymbolSsm.json5
+)
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-printable-expectsymbolssm
+    FACET_PKG xo_printable2
+    INPUT idl/IPrintable_DExpectSymbolSsm.json5
+)
+
+# ----------------------------------------------------------------
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-expecttypessm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DExpectTypeSsm.json5
+)
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-printable-expecttypessm
+    FACET_PKG xo_printable2
+    INPUT idl/IPrintable_DExpectTypeSsm.json5
+)
+
+# ----------------------------------------------------------------
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-expectlisttypessm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DExpectListTypeSsm.json5
+)
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-printable-expectlisttypessm
+    FACET_PKG xo_printable2
+    INPUT idl/IPrintable_DExpectListTypeSsm.json5
+)
+
+# ----------------------------------------------------------------
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-expectexprssm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DExpectExprSsm.json5
+)
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-printable-expectexprssm
+    FACET_PKG xo_printable2
+    INPUT idl/IPrintable_DExpectExprSsm.json5
+)
+
+# ----------------------------------------------------------------
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-progressssm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DProgressSsm.json5
+)
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-printable-progressssm
+    FACET_PKG xo_printable2
+    INPUT idl/IPrintable_DProgressSsm.json5
+)
+
+# ----------------------------------------------------------------
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-quotessm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DQuoteSsm.json5
+)
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-printable-quotessm
+    FACET_PKG xo_printable2
+    INPUT idl/IPrintable_DQuoteSsm.json5
+)
+
+# ----------------------------------------------------------------
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-expectqliteralssm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DExpectQLiteralSsm.json5
+)
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-printable-expectqliteralssm
+    FACET_PKG xo_printable2
+    INPUT idl/IPrintable_DExpectQLiteralSsm.json5
+)
+
+# ----------------------------------------------------------------
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-expectqlistssm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DExpectQListSsm.json5
+)
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-printable-expectqlistssm
+    FACET_PKG xo_printable2
+    INPUT idl/IPrintable_DExpectQListSsm.json5
+)
+
+# ----------------------------------------------------------------
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-expectqdictssm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DExpectQDictSsm.json5
+)
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-printable-expectqdictssm
+    FACET_PKG xo_printable2
+    INPUT idl/IPrintable_DExpectQDictSsm.json5
+)
+
+# ----------------------------------------------------------------
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-syntaxstatemachine-expectqarrayssm
+    FACET_PKG xo_reader2
+    INPUT idl/ISyntaxStateMachine_DExpectQArraySsm.json5
+)
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-printable-expectqarrayssm
+    FACET_PKG xo_printable2
+    INPUT idl/IPrintable_DExpectQArraySsm.json5
+)
+
+# ----------------------------------------------------------------
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-gcobject-globalenv
+    FACET_PKG xo_alloc2
+    INPUT idl/IGCObject_DGlobalEnv.json5
+)
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-reader2-facetimpl-printable-globalenv
+    FACET_PKG xo_printable2
+    INPUT idl/IPrintable_DGlobalEnv.json5
+)
+
+# ----------------------------------------------------------------
+
+xo_add_genfacet_all(xo-reader2-genfacet-all)
 
 # ----------------------------------------------------------------
 # shared library
 
-add_subdirectory(src/expression2)
+add_subdirectory(src/reader2)
 
 # ----------------------------------------------------------------
-# cmake helper (for external xo-expression2 users)
+# example programs
+
+add_subdirectory(example)
+
+# ----------------------------------------------------------------
+# cmake helper (for external xo-reader2 users)
 
 xo_export_cmake_config(${PROJECT_NAME} ${PROJECT_VERSION} ${PROJECT_NAME}Targets)
 

DESIGN.md

@@ -0,0 +1,21 @@
+Uses arena allocators for fast+efficient parsing.
+
+Composition of nested state machines.
+
+## SchematikaParser
+
+Parser to convert schematika text to expressions.
+
+### Details
+
+Partial GCObject facet support, so a SchmeatikaParser instance can
+be a gc root.
+
+## SyntaxStateMachine
+
+a state machine dedicated to some particular Schematika syntax.
+Examples: if-expression, type declaration, function call
+
+## DToplevelSeqSsm
+
+top-level expression sequence

cmake/xo_reader2Config.cmake.in

@@ -6,14 +6,13 @@ include(CMakeFindDependencyMacro)
 #       must coordinate with xo_dependency() calls
 #       in CMakeLists.txt
 #
-find_dependency(xo_type)
-find_dependency(xo_gc)
-find_dependency(reflect)
+find_dependency(xo_numeric)
 find_dependency(xo_procedure2)
-find_dependency(xo_printable2)
-find_dependency(xo_flatstring)
-find_dependency(cmake)
-find_dependency(indentlog)
+find_dependency(xo_gc)
+find_dependency(xo_type)
+find_dependency(xo_tokenizer2)
+find_dependency(xo_expression2)
+find_dependency(subsys)
 
 include("${CMAKE_CURRENT_LIST_DIR}/@PROJECT_NAME@Targets.cmake")
 include("${CMAKE_CURRENT_LIST_DIR}/@PROJECT_NAME@Share.cmake")

doc/README.md

@@ -0,0 +1,6 @@
+diagram for parsing stack.
+stack growing down for nested ssm's
+
+`on_if_token` etc going to same state
+
+`on_parsed_xxx` going back up the stack

doc/glossary.rst

@@ -0,0 +1,3 @@
+ssm = syntax state machine
+psm = parser state machine
+ckp = checkpoint

example/CMakeLists.txt

@@ -0,0 +1 @@
+add_subdirectory(readerreplxx)

example/readerreplxx/CMakeLists.txt

@@ -0,0 +1,14 @@
+# xo-reader2/example/readerreplxx/CMakeLists.txt
+
+set(SELF_EXE xo_reader2_readereplxx)
+set(SELF_SRCS readerreplxx.cpp)
+
+if (XO_ENABLE_EXAMPLES)
+    xo_add_executable(${SELF_EXE} ${SELF_SRCS})
+    xo_self_dependency(${SELF_EXE} xo_reader2)
+    xo_external_target_dependency(${SELF_EXE} replxx replxx::replxx)
+
+    # replxx requires this
+    find_package(Threads REQUIRED)
+    target_link_libraries(${SELF_EXE} PUBLIC Threads::Threads)
+endif()

example/readerreplxx/readerreplxx.cpp

@@ -0,0 +1,248 @@
+/** @file readerreplxx.cpp **/
+
+#include <xo/reader2/init_reader2.hpp>
+#include <xo/reader2/SchematikaReader.hpp>
+#include <xo/gc/X1Collector.hpp>
+#include <xo/gc/detail/IAllocator_DX1Collector.hpp>
+#include <xo/alloc2/Arena.hpp>
+#include <xo/alloc2/Allocator.hpp>
+#include <xo/printable2/Printable.hpp>
+#include <xo/facet/FacetRegistry.hpp>
+#include <xo/facet/obj.hpp>
+#include <xo/subsys/Subsystem.hpp>
+#include <replxx.hxx>
+#include <iostream>
+#include <unistd.h> // for isatty
+
+// presumeably replxx assumes input is a tty
+//
+bool replxx_getline(bool interactive,
+                    bool is_at_toplevel,
+                    replxx::Replxx & rx,
+                    const char ** p_input)
+{
+    using namespace std;
+
+    char const * prompt = "";
+
+    if (interactive) {
+        prompt = ((is_at_toplevel) ? "> " : ". ");
+    }
+
+    const char * input_cstr = rx.input(prompt);
+
+    bool retval = (input_cstr != nullptr);
+
+    if (retval)
+        *p_input = input_cstr;
+
+    if (input_cstr)
+        rx.history_add(input_cstr);
+
+    return retval;
+}
+
+void
+welcome(std::ostream & os)
+{
+    using namespace std;
+
+    os << "read-eval-print loop for schematika expressions" << endl;
+    os << "  ctrl-a/ctrl-e   beginning/end of line" << endl;
+    os << "  ctrl-u          delete entire line" << endl;
+    os << "  ctrl-k          delete to end of line" << endl;
+    os << "  meta-<bs>       backward delete word" << endl;
+    os << "  <up>|meta-p     previous command from history" << endl;
+    os << "  <down>|meta-n   next command from history" << endl;
+    os << "  <pgup>/<pgdown> page through history faster" << endl;
+    os << "  ctrl-s/ctrl-r   forward/backward history search" << endl;
+    os << endl;
+}
+
+namespace {
+    using xo::scm::SchematikaReader;
+    using xo::scm::AExpression;
+    using xo::print::APrintable;
+    using xo::print::ppstate_standalone;
+    using xo::print::ppconfig;
+    using xo::facet::FacetRegistry;
+    using xo::facet::obj;
+    using xo::xtag;
+    using xo::scope;
+    using std::cout;
+    using std::endl;
+
+    /** body of read-parse-print loop
+     *
+     *  true -> no errors;
+     *  false -> reader encountered error
+     **/
+    bool
+    reader_seq(SchematikaReader * p_reader,
+               SchematikaReader::span_type * p_input,
+               bool eof,
+               bool debug_flag)
+    {
+        scope log(XO_DEBUG(debug_flag));
+
+        if (!p_input || p_input->empty())
+            return true;
+
+        auto [expr, remaining, error] = p_reader->read_expr(*p_input, eof);
+
+        obj<APrintable> expr_pr;
+
+        if (expr) {
+            expr_pr = FacetRegistry::instance().variant<APrintable,AExpression>(expr);
+            assert(expr_pr);
+        }
+
+        if (log) {
+            if (expr_pr) {
+                log(xtag("expr", expr_pr));
+            }
+            log(xtag("remaining", remaining));
+            log(xtag("error", error));
+        }
+
+        if (expr) {
+            ppconfig ppc;
+            ppstate_standalone pps(&cout, 0, &ppc);
+
+            pps.prettyn(expr_pr);
+
+            p_reader->reset_result();
+
+            *p_input = remaining;
+
+            return true;
+        } else if (error.is_error()) {
+            cout << "parsing error (detected in " << error.src_function() << "): " << endl;
+            error.report(cout);
+
+            /* discard stashed remainder of input line
+             * (for nicely-formatted errors)
+             */
+            p_reader->reset_to_idle_toplevel();
+
+            return false;
+        } else {
+            *p_input = remaining;
+
+            /* partial expression or whitespace input, no error */
+            return true;
+        }
+    }
+}
+
+struct AppConfig {
+    using ReaderConfig = xo::scm::ReaderConfig;
+    using X1CollectorConfig = xo::mm::X1CollectorConfig;
+    using ArenaConfig = xo::mm::ArenaConfig;
+
+    AppConfig() {
+        rdr_config_.reader_debug_flag_ = true;
+        //rdr_config.parser_debug_flag_ = true;
+        //rdr_config.tk_debug_flag_ = true;
+    }
+
+    std::size_t max_history_size_ = 1000;
+    std::string repl_history_fname_ = "repl_history.txt";;
+    ReaderConfig rdr_config_;
+    X1CollectorConfig x1_config_ = (X1CollectorConfig().with_name("gc").with_size(4*1024*1024));
+    ArenaConfig fixed_config_ = (ArenaConfig().with_name("fixed").with_size(4*1024));
+};
+
+struct AppContext {
+    using AAllocator = xo::mm::AAllocator;
+    using DX1Collector = xo::mm::DX1Collector;
+    using X1CollectorConfig = xo::mm::X1CollectorConfig;
+    using DArena = xo::mm::DArena;
+    using ArenaConfig = xo::mm::ArenaConfig;
+    using Replxx = replxx::Replxx;
+
+    AppContext(const AppConfig & cfg = AppConfig()) : config_{cfg},
+                                                      x1_{cfg.x1_config_},
+                                                      fixed_{cfg.fixed_config_},
+                                                      rdr_{config_.rdr_config_,
+                                                           x1_.ref(),
+                                                           obj<AAllocator,DArena>(&fixed_)}
+    {
+        rx_.set_max_history_size(config_.max_history_size_);
+        rx_.history_load(config_.repl_history_fname_);
+        //    rx.bind_key_internal(Replxx::KEY::control('p'), "history_previous");
+        //    rx.bind_key_internal(Replxx::KEY::control('n'), "history_next");
+    }
+
+    AppConfig config_;
+    Replxx rx_;
+    /** collector/allocator for schematika expressions **/
+    DX1Collector x1_;
+    /** e.g. for DArenaHashMap within global symtab **/
+    DArena fixed_;
+    SchematikaReader rdr_;
+};
+
+int
+main()
+{
+    using namespace replxx;
+
+    using xo::scm::SchematikaReader;
+    using xo::scm::ReaderConfig;
+    using xo::mm::AAllocator;
+    using xo::mm::DX1Collector;
+    using xo::mm::DArena;
+    using xo::facet::with_facet;
+    using xo::facet::obj;
+    using xo::S_reader2_tag;
+    using xo::InitSubsys;
+    using xo::Subsystem;
+    using xo::scope;
+    using namespace std;
+
+    bool interactive = isatty(STDIN_FILENO);
+
+    InitSubsys<S_reader2_tag>::require();
+    Subsystem::initialize_all();
+
+    AppConfig cfg;
+    AppContext cx(cfg);
+
+    constexpr bool c_debug_flag = false;
+    scope log(XO_DEBUG(c_debug_flag));
+
+    using span_type = SchematikaReader::span_type;
+
+    welcome(cerr);
+
+    cx.rdr_.begin_interactive_session();
+
+    bool eof = false;
+    const char * input_str = nullptr;
+    span_type input;
+
+    while (replxx_getline(interactive, cx.rdr_.is_at_toplevel(), cx.rx_, &input_str)) {
+        if (input_str && *input_str) {
+            input = span_type::from_cstr(input_str);
+
+            while (!input.empty()
+                   && reader_seq(&cx.rdr_, &input, false /*eof*/, c_debug_flag))
+                {
+                    ;
+                }
+
+            /* here: either:
+             * 1. input.empty() or
+             * 2. error encountered
+             */
+        }
+    }
+
+    /* reminder: eof can complete at most one token */
+    reader_seq(&cx.rdr_, &input, true /*eof*/, c_debug_flag);
+
+    cx.rx_.history_save(cx.config_.repl_history_fname_);
+}
+
+/* end readerreplxx.cpp */

idl/Expression.json5

@@ -1,74 +0,0 @@
-{
-    mode: "facet",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
-    includes: [ "\"TypeRef.hpp\"",
-                "\"exprtype.hpp\"",
-                "<xo/reflect/TypeDescr.hpp>"],
-    // extra includes in Expression.hpp, if any
-    user_hpp_includes: [],
-    namespace1: "xo",
-    namespace2: "scm",
-    // text after includes, before AExpression
-    pretext: [ "// {pretext} here" ],
-    facet: "Expression",
-    detail_subdir: "detail",
-    brief: "a schematika expression",
-    using_doxygen: true,
-    doc: [
-        "Representation for executable Schematika expressions"
-    ],
-    types: [
-        // using TypeDescr = xo::reflect::TypeDescr;
-        {
-            name: "TypeDescr",
-            doc: ["struct describing a type"],
-            definition: "xo::reflect::TypeDescr"
-        },
-    ],
-    const_methods: [
-        {
-            name: "extype",
-            doc: ["expression type (constant | apply | ..)"],
-            return_type: "exprtype",
-            args: [],
-            const: true,
-            noexcept: true,
-            attributes: [],
-        },
-        {
-            name: "typeref",
-            doc: ["placeholder for type giving possible values for this expression"],
-            return_type: "TypeRef",
-            args: [],
-            const: true,
-            noexcept: true,
-            attributes: [],
-        },
-        {
-            name: "valuetype",
-            doc: ["type giving possible values for this expression. Maybe null before typecheck"],
-            return_type: "TypeDescr",
-            args: [],
-            const: true,
-            noexcept: true,
-            attributes: [],
-        },
-    ],
-    nonconst_methods: [
-        {
-            name: "assign_valuetype",
-            doc: ["assing to valuetype member. Useful when scaffolding expressions"],
-            return_type: "void",
-            args: [
-                // void assign_valuetype(TypeDescr td)
-                {type: "TypeDescr", name: "td"},
-            ],
-            const: false,
-            noexcept: true,
-            attributes: [],
-        }
-    ],
-    router_facet_explicit_content: [ ],
-}

idl/IExpression_DApplyExpr.json5

@@ -1,15 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
-    includes: [ "\"Expression.hpp\"" ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/Expression.json5",
-    brief: "provide AExpression interface for DApplyExpr state",
-    using_doxygen: true,
-    repr: "DApplyExpr",
-    doc: ["doc for IExpression+DApplyExpr" ],
-}

idl/IExpression_DConstant.json5

@@ -1,15 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
-    includes: [ "\"Expression.hpp\"" ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/Expression.json5",
-    brief: "provide AExpression interface for DConstant state",
-    using_doxygen: true,
-    repr: "DConstant",
-    doc: ["doc for something or other IExpression+DConstant" ],
-}

idl/IExpression_DDefineExpr.json5

@@ -1,15 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
-    includes: [ "\"Expression.hpp\"" ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/Expression.json5",
-    brief: "provide AExpression interface for DDefineExpr state",
-    using_doxygen: true,
-    repr: "DDefineExpr",
-    doc: ["doc for IExpression+DDefineExpr" ],
-}

idl/IExpression_DIfElseExpr.json5

@@ -1,15 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
-    includes: [ "\"Expression.hpp\"" ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/Expression.json5",
-    brief: "provide AExpression interface for DIfElseExpr state",
-    using_doxygen: true,
-    repr: "DIfElseExpr",
-    doc: ["doc for IExpression+DIfElseExpr" ],
-}

idl/IExpression_DLambdaExpr.json5

@@ -1,15 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
-    includes: [ "\"Expression.hpp\"" ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/Expression.json5",
-    brief: "provide AExpression interface for DLambdaExpr state",
-    using_doxygen: true,
-    repr: "DLambdaExpr",
-    doc: ["doc for IExpression+DLambdaExpr" ],
-}

idl/IExpression_DSequenceExpr.json5

@@ -1,15 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
-    includes: [ "\"Expression.hpp\"" ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/Expression.json5",
-    brief: "provide AExpression interface for DSequenceExpr state",
-    using_doxygen: true,
-    repr: "DSequenceExpr",
-    doc: ["doc for something or other IExpression+DSequenceExpr" ],
-}

idl/IExpression_DVarRef.json5

@@ -1,15 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
-    includes: [ "\"Expression.hpp\"" ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/Expression.json5",
-    brief: "provide AExpression interface for DVarRef state",
-    using_doxygen: true,
-    repr: "DVarRef",
-    doc: ["doc for IExpression+DVarRef" ],
-}

idl/IExpression_DVariable.json5

@@ -1,15 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2/facet",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "variable",
-    includes: [ "\"Expression.hpp\"" ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/Expression.json5",
-    brief: "provide AExpression interface for DVariable state",
-    using_doxygen: true,
-    repr: "DVariable",
-    doc: ["doc for IExpression+DVariable" ],
-}

idl/IGCObject_DApplyExpr.json5

@@ -1,18 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
-    includes: [
-        "<xo/alloc2/GCObject.hpp>",
-        "<xo/alloc2/Allocator.hpp>"
-    ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/GCObject.json5",
-    brief: "provide AGCObject interface for DApplyExpr",
-    using_doxygen: true,
-    repr: "DApplyExpr",
-    doc: [ "implement AGCObject for DApplyExpr" ],
-}

idl/IGCObject_DConstant.json5

@@ -1,18 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
-    includes: [
-        "<xo/alloc2/GCObject.hpp>",
-        "<xo/alloc2/Allocator.hpp>"
-    ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/GCObject.json5",
-    brief: "provide AGCObject interface for DConstant",
-    using_doxygen: true,
-    repr: "DConstant",
-    doc: [ "implement AGCObject for DConstant" ],
-}

idl/IGCObject_DDefineExpr.json5

@@ -1,18 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "define",
-    includes: [
-        "<xo/alloc2/GCObject.hpp>",
-        "<xo/alloc2/Allocator.hpp>"
-    ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/GCObject.json5",
-    brief: "provide AGCObject interface for DDefineExpr",
-    using_doxygen: true,
-    repr: "DDefineExpr",
-    doc: [ "implement AGCObject for DDefineExpr" ],
-}

idl/IGCObject_DGlobalEnv.json5

@@ -1,8 +1,8 @@
 {
     mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "env",
     includes: [
         "<xo/alloc2/GCObject.hpp>",
         "<xo/alloc2/Allocator.hpp>"
@@ -11,8 +11,8 @@
     namespace1: "xo",
     namespace2: "scm",
     facet_idl: "idl/GCObject.json5",
-    brief: "provide AGCObject interface for DVarRef",
+    brief: "provide AGCObject interface for GlobalEnv",
     using_doxygen: true,
-    repr: "DVarRef",
-    doc: [ "implement AGCObject for DVarRef" ],
+    repr: "DGlobalEnv",
+    doc: [ "implement AGCObject for DGlobalEnv" ],
 }

idl/IGCObject_DGlobalSymtab.json5

@@ -1,18 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "symtab",
-    includes: [
-        "<xo/alloc2/GCObject.hpp>",
-        "<xo/alloc2/Allocator.hpp>"
-    ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/GCObject.json5",
-    brief: "provide AGCObject interface for DGlobalSymtab",
-    using_doxygen: true,
-    repr: "DGlobalSymtab",
-    doc: [ "implement AGCObject for DGlobalSymtab" ],
-}

idl/IGCObject_DIfElseExpr.json5

@@ -1,18 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
-    includes: [
-        "<xo/alloc2/GCObject.hpp>",
-        "<xo/alloc2/Allocator.hpp>"
-    ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/GCObject.json5",
-    brief: "provide AGCObject interface for DIfElseExpr",
-    using_doxygen: true,
-    repr: "DIfElseExpr",
-    doc: [ "implement AGCObject for DIfElseExpr" ],
-}

idl/IGCObject_DLambdaExpr.json5

@@ -1,18 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
-    includes: [
-        "<xo/alloc2/GCObject.hpp>",
-        "<xo/alloc2/Allocator.hpp>"
-    ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/GCObject.json5",
-    brief: "provide AGCObject interface for DLambdaExpr",
-    using_doxygen: true,
-    repr: "DLambdaExpr",
-    doc: [ "implement AGCObject for DLambdaExpr" ],
-}

idl/IGCObject_DLocalSymtab.json5

@@ -1,18 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "symtab",
-    includes: [
-        "<xo/alloc2/GCObject.hpp>",
-        "<xo/alloc2/Allocator.hpp>"
-    ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/GCObject.json5",
-    brief: "provide AGCObject interface for DLocalSymtab",
-    using_doxygen: true,
-    repr: "DLocalSymtab",
-    doc: [ "implement AGCObject for DLocalSymtab" ],
-}

idl/IGCObject_DSchematikaParser.json5

@@ -0,0 +1,18 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "parser",
+    includes: [
+        "<xo/alloc2/GCObject.hpp>",
+        "<xo/alloc2/Allocator.hpp>"
+    ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/GCObject.json5",
+    brief: "provide AGCObject interface for SchematikaParser",
+    using_doxygen: true,
+    repr: "DSchematikaParser",
+    doc: [ "implement AGCObject for DSchematikaParser" ],
+}

idl/IGCObject_DSequenceExpr.json5

@@ -1,18 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
-    includes: [
-        "<xo/alloc2/GCObject.hpp>",
-        "<xo/alloc2/Allocator.hpp>"
-    ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/GCObject.json5",
-    brief: "provide AGCObject interface for DSequenceExpr",
-    using_doxygen: true,
-    repr: "DSequenceExpr",
-    doc: [ "implement AGCObject for DSequenceExpr" ],
-}

idl/IGCObject_DTypename.json5

@@ -1,18 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "typename",
-    includes: [
-//        "<xo/alloc2/GCObject.hpp>",
-//        "<xo/alloc2/Allocator.hpp>"
-    ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/GCObject.json5",
-    brief: "provide AGCObject interface for DTypename",
-    using_doxygen: true,
-    repr: "DTypename",
-    doc: [ "implement AGCObject for DTypename" ],
-}

idl/IGCObject_DVariable.json5

@@ -1,18 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2/facet",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "variable",
-    includes: [
-        "<xo/alloc2/GCObject.hpp>",
-        "<xo/alloc2/Allocator.hpp>"
-    ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/GCObject.json5",
-    brief: "provide AGCObject interface for DVariable",
-    using_doxygen: true,
-    repr: "DVariable",
-    doc: [ "implement AGCObject for DVariable" ],
-}

idl/IPrintable_DApplyExpr.json5

@@ -1,16 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
-    includes: [ "<xo/printable2/Printable.hpp>",
-                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/Printable.json5",
-    brief: "provide APrintable interface for DApplyExpr",
-    using_doxygen: true,
-    repr: "DApplyExpr",
-    doc: [ "implement APrintable for DApplyExpr" ],
-}

idl/IPrintable_DApplySsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "apply",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DApplySsm",
+    using_doxygen: true,
+    repr: "DApplySsm",
+    doc: [ "implement APrintable for DApplySsm" ],
+}

idl/IPrintable_DConstant.json5

@@ -1,16 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
-    includes: [ "<xo/printable2/Printable.hpp>",
-                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/Printable.json5",
-    brief: "provide APrintable interface for DConstant",
-    using_doxygen: true,
-    repr: "DConstant",
-    doc: [ "implement APrintable for DConstant" ],
-}

idl/IPrintable_DDefineExpr.json5

@@ -1,16 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
-    includes: [ "<xo/printable2/Printable.hpp>",
-                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/Printable.json5",
-    brief: "provide APrintable interface for DDefineExpr",
-    using_doxygen: true,
-    repr: "DDefineExpr",
-    doc: [ "implement APrintable for DDefineExpr" ],
-}

idl/IPrintable_DDefineSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "define",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DDefineSsm",
+    using_doxygen: true,
+    repr: "DDefineSsm",
+    doc: [ "implement APrintable for DDefineSsm" ],
+}

idl/IPrintable_DDeftypeSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "deftype",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DDeftypeSsm",
+    using_doxygen: true,
+    repr: "DDeftypeSsm",
+    doc: [ "implement APrintable for DDeftypeSsm" ],
+}

idl/IPrintable_DExpectExprSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DExpectExprSsm",
+    using_doxygen: true,
+    repr: "DExpectExprSsm",
+    doc: [ "implement APrintable for DExpectExprSsm" ],
+}

idl/IPrintable_DExpectFormalArgSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "expect_formal_arg",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DExpectFormalArgSsm",
+    using_doxygen: true,
+    repr: "DExpectFormalArgSsm",
+    doc: [ "implement APrintable for DExpectFormalArgSsm" ],
+}

idl/IPrintable_DExpectFormalArglistSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DExpectFormalArglistSsm",
+    using_doxygen: true,
+    repr: "DExpectFormalArglistSsm",
+    doc: [ "implement APrintable for DExpectFormalArglistSsm" ],
+}

idl/IPrintable_DExpectListTypeSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "expect_listtype",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DExpectListTypeSsm",
+    using_doxygen: true,
+    repr: "DExpectListTypeSsm",
+    doc: [ "implement APrintable for DExpectListTypeSsm" ],
+}

idl/IPrintable_DExpectQArraySsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DExpectQArraySsm",
+    using_doxygen: true,
+    repr: "DExpectQArraySsm",
+    doc: [ "implement APrintable for DExpectQArraySsm" ],
+}

idl/IPrintable_DExpectQDictSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "expect_qdict",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DExpectQDictSsm",
+    using_doxygen: true,
+    repr: "DExpectQDictSsm",
+    doc: [ "implement APrintable for DExpectQDictSsm" ],
+}

idl/IPrintable_DExpectQListSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DExpectQListSsm",
+    using_doxygen: true,
+    repr: "DExpectQListSsm",
+    doc: [ "implement APrintable for DExpectQListSsm" ],
+}

idl/IPrintable_DExpectQLiteralSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DExpectQLiteralSsm",
+    using_doxygen: true,
+    repr: "DExpectQLiteralSsm",
+    doc: [ "implement APrintable for DExpectQLiteralSsm" ],
+}

idl/IPrintable_DExpectSymbolSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DExpectSymbolSsm",
+    using_doxygen: true,
+    repr: "DExpectSymbolSsm",
+    doc: [ "implement APrintable for DExpectSymbolSsm" ],
+}

idl/IPrintable_DExpectTypeSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DExpectTypeSsm",
+    using_doxygen: true,
+    repr: "DExpectTypeSsm",
+    doc: [ "implement APrintable for DExpectTypeSsm" ],
+}

idl/IPrintable_DGlobalEnv.json5

@@ -1,16 +1,16 @@
 {
     mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "env",
     includes: [ "<xo/printable2/Printable.hpp>",
                 "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
     local_types: [ ],
     namespace1: "xo",
     namespace2: "scm",
     facet_idl: "idl/Printable.json5",
-    brief: "provide APrintable interface for DVarRef",
+    brief: "provide APrintable interface for DGlobalEnv",
     using_doxygen: true,
-    repr: "DVarRef",
-    doc: [ "implement APrintable for DVarRef" ],
+    repr: "DGlobalEnv",
+    doc: [ "implement APrintable for DGlobalEnv" ],
 }

idl/IPrintable_DGlobalSymtab.json5

@@ -1,16 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "symtab",
-    includes: [ "<xo/printable2/Printable.hpp>",
-                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/Printable.json5",
-    brief: "provide APrintable interface for DGlobalSymtab",
-    using_doxygen: true,
-    repr: "DGlobalSymtab",
-    doc: [ "implement APrintable for DGlobalSymtab" ],
-}

idl/IPrintable_DIfElseExpr.json5

@@ -1,16 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
-    includes: [ "<xo/printable2/Printable.hpp>",
-                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/Printable.json5",
-    brief: "provide APrintable interface for DIfElseExpr",
-    using_doxygen: true,
-    repr: "DIfElseExpr",
-    doc: [ "implement APrintable for DIfElseExpr" ],
-}

idl/IPrintable_DIfElseSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ifelse",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DIfElseSsm",
+    using_doxygen: true,
+    repr: "DIfElseSsm",
+    doc: [ "implement APrintable for DIfElseSsm" ],
+}

idl/IPrintable_DLambdaExpr.json5

@@ -1,16 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
-    includes: [ "<xo/printable2/Printable.hpp>",
-                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/Printable.json5",
-    brief: "provide APrintable interface for DLambdaExpr",
-    using_doxygen: true,
-    repr: "DLambdaExpr",
-    doc: [ "implement APrintable for DLambdaExpr" ],
-}

idl/IPrintable_DLambdaSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "lambda",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DLambdaSsm",
+    using_doxygen: true,
+    repr: "DLambdaSsm",
+    doc: [ "implement APrintable for DLambdaSsm" ],
+}

idl/IPrintable_DLocalSymtab.json5

@@ -1,16 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "symtab",
-    includes: [ "<xo/printable2/Printable.hpp>",
-                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/Printable.json5",
-    brief: "provide APrintable interface for DLocalSymtab",
-    using_doxygen: true,
-    repr: "DLocalSymtab",
-    doc: [ "implement APrintable for DLocalSymtab" ],
-}

idl/IPrintable_DParenSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "paren",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DParenSsm",
+    using_doxygen: true,
+    repr: "DParenSsm",
+    doc: [ "implement APrintable for DParenSsm" ],
+}

idl/IPrintable_DProgressSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DProgressSsm",
+    using_doxygen: true,
+    repr: "DProgressSsm",
+    doc: [ "implement APrintable for DProgressSsm" ],
+}

idl/IPrintable_DQuoteSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "quote",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DQuoteSsm",
+    using_doxygen: true,
+    repr: "DQuoteSsm",
+    doc: [ "implement APrintable for DQuoteSsm" ],
+}

idl/IPrintable_DSequenceExpr.json5

@@ -1,16 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "detail",
-    includes: [ "<xo/printable2/Printable.hpp>",
-                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/Printable.json5",
-    brief: "provide APrintable interface for DSequenceExpr",
-    using_doxygen: true,
-    repr: "DSequenceExpr",
-    doc: [ "implement APrintable for DSequenceExpr" ],
-}

idl/IPrintable_DSequenceSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DSequenceSsm",
+    using_doxygen: true,
+    repr: "DSequenceSsm",
+    doc: [ "implement APrintable for DSequenceSsm" ],
+}

idl/IPrintable_DToplevelSeqSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "<xo/printable2/Printable.hpp>",
+                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
+    local_types: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Printable.json5",
+    brief: "provide APrintable interface for DToplevelSeqSsm",
+    using_doxygen: true,
+    repr: "DToplevelSeqSsm",
+    doc: [ "implement APrintable for DToplevelSeqSsm" ],
+}

idl/IPrintable_DTypename.json5

@@ -1,16 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "typename",
-    includes: [ "<xo/printable2/Printable.hpp>",
-                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/Printable.json5",
-    brief: "provide APrintable interface for DTypename",
-    using_doxygen: true,
-    repr: "DTypename",
-    doc: [ "implement APrintable for DTypename" ],
-}

idl/IPrintable_DVariable.json5

@@ -1,16 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2/facet",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "variable",
-    includes: [ "<xo/printable2/Printable.hpp>",
-                "<xo/printable2/detail/IPrintable_Xfer.hpp>" ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/Printable.json5",
-    brief: "provide APrintable interface for DVariable",
-    using_doxygen: true,
-    repr: "DVariable",
-    doc: [ "implement APrintable for DVariable" ],
-}

idl/ISymbolTable_DGlobalSymtab.json5

@@ -1,15 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "symtab",
-    includes: [ ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/SymbolTable.json5",
-    brief: "provide ASymbolTable interface for DGlobalSymtab",
-    using_doxygen: true,
-    repr: "DGlobalSymtab",
-    doc: [ "implement ASymbolTable for DGlobalSymtab" ],
-}

idl/ISymbolTable_DLocalSymtab.json5

@@ -1,15 +0,0 @@
-{
-    mode: "implementation",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "symtab",
-    includes: [ ],
-    local_types: [ ],
-    namespace1: "xo",
-    namespace2: "scm",
-    facet_idl: "idl/SymbolTable.json5",
-    brief: "provide ASymbolTable interface for DLocalSymtab",
-    using_doxygen: true,
-    repr: "DLocalSymtab",
-    doc: [ "implement ASymbolTable for DLocalSymtab" ],
-}

idl/ISyntaxStateMachine_DApplySsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "apply",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DApplySsm",
+    using_doxygen: true,
+    repr: "DApplySsm",
+    doc: [ "implement ASyntaxStateMachine for DApplySsm" ],
+}

idl/ISyntaxStateMachine_DDefineSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "define",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DDefineSsm",
+    using_doxygen: true,
+    repr: "DDefineSsm",
+    doc: [ "implement ASyntaxStateMachine for DDefineSsm" ],
+}

idl/ISyntaxStateMachine_DDeftypeSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "deftype",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DDeftypeSsm",
+    using_doxygen: true,
+    repr: "DDeftypeSsm",
+    doc: [ "implement ASyntaxStateMachine for DDeftypeSsm" ],
+}

idl/ISyntaxStateMachine_DExpectExprSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DExpectExprSsm",
+    using_doxygen: true,
+    repr: "DExpectExprSsm",
+    doc: [ "implement ASyntaxStateMachine for DExpectExprSsm" ],
+}

idl/ISyntaxStateMachine_DExpectFormalArgSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "expect_formal_arg",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DExpectFormalArgSsm",
+    using_doxygen: true,
+    repr: "DExpectFormalArgSsm",
+    doc: [ "implement ASyntaxStateMachine for DExpectFormalArgSsm" ],
+}

idl/ISyntaxStateMachine_DExpectFormalArglistSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DExpectFormalArglistSsm",
+    using_doxygen: true,
+    repr: "DExpectFormalArglistSsm",
+    doc: [ "implement ASyntaxStateMachine for DExpectFormalArglistSsm" ],
+}

idl/ISyntaxStateMachine_DExpectListTypeSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "expect_listtype",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DExpectListTypeSsm",
+    using_doxygen: true,
+    repr: "DExpectListTypeSsm",
+    doc: [ "implement ASyntaxStateMachine for DExpectListTypeSsm" ],
+}

idl/ISyntaxStateMachine_DExpectQArraySsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DExpectQArraySsm",
+    using_doxygen: true,
+    repr: "DExpectQArraySsm",
+    doc: [ "implement ASyntaxStateMachine for DExpectQArraySsm" ],
+}

idl/ISyntaxStateMachine_DExpectQDictSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "expect_qdict",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DExpectQDictSsm",
+    using_doxygen: true,
+    repr: "DExpectQDictSsm",
+    doc: [ "implement ASyntaxStateMachine for DExpectQDictSsm" ],
+}

idl/ISyntaxStateMachine_DExpectQListSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DExpectQListSsm",
+    using_doxygen: true,
+    repr: "DExpectQListSsm",
+    doc: [ "implement ASyntaxStateMachine for DExpectQListSsm" ],
+}

idl/ISyntaxStateMachine_DExpectQLiteralSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DExpectQLiteralSsm",
+    using_doxygen: true,
+    repr: "DExpectQLiteralSsm",
+    doc: [ "implement ASyntaxStateMachine for DExpectQLiteralSsm" ],
+}

idl/ISyntaxStateMachine_DExpectSymbolSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DExpectSymbolSsm",
+    using_doxygen: true,
+    repr: "DExpectSymbolSsm",
+    doc: [ "implement ASyntaxStateMachine for DExpectSymbolSsm" ],
+}

idl/ISyntaxStateMachine_DExpectTypeSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DExpectTypeSsm",
+    using_doxygen: true,
+    repr: "DExpectTypeSsm",
+    doc: [ "implement ASyntaxStateMachine for DExpectTypeSsm" ],
+}

idl/ISyntaxStateMachine_DIfElseSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ifelse",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DIfElseSsm",
+    using_doxygen: true,
+    repr: "DIfElseSsm",
+    doc: [ "implement ASyntaxStateMachine for DIfElseSsm" ],
+}

idl/ISyntaxStateMachine_DLambdaSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "lambda",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DLambdaSsm",
+    using_doxygen: true,
+    repr: "DLambdaSsm",
+    doc: [ "implement ASyntaxStateMachine for DLambdaSsm" ],
+}

idl/ISyntaxStateMachine_DParenSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "paren",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DParenSsm",
+    using_doxygen: true,
+    repr: "DParenSsm",
+    doc: [ "implement ASyntaxStateMachine for DParenSsm" ],
+}

idl/ISyntaxStateMachine_DProgressSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DProgressSsm",
+    using_doxygen: true,
+    repr: "DProgressSsm",
+    doc: [ "implement ASyntaxStateMachine for DProgressSsm" ],
+}

idl/ISyntaxStateMachine_DQuoteSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2/facet",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "quote",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DQuoteSsm",
+    using_doxygen: true,
+    repr: "DQuoteSsm",
+    doc: [ "implement ASyntaxStateMachine for DQuoteSsm" ],
+}

idl/ISyntaxStateMachine_DSequenceSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DSequenceSsm",
+    using_doxygen: true,
+    repr: "DSequenceSsm",
+    doc: [ "implement ASyntaxStateMachine for DSequenceSsm" ],
+}

idl/ISyntaxStateMachine_DToplevelSeqSsm.json5

@@ -0,0 +1,16 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    includes: [ "\"SyntaxStateMachine.hpp\"",
+                "\"ssm/ISyntaxStateMachine_Xfer.hpp\"" ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/SyntaxStateMachine.json5",
+    brief: "provide ASyntaxStateMachine interface for DToplevelSeqSsm",
+    using_doxygen: true,
+    repr: "DToplevelSeqSsm",
+    doc: [ "implement ASyntaxStateMachine for DToplevelSeqSsm" ],
+}

idl/SymbolTable.json5

@@ -1,63 +0,0 @@
-{
-    mode: "facet",
-    output_cpp_dir: "src/expression2",
-    output_hpp_dir: "include/xo/expression2",
-    output_impl_subdir: "symtab",
-    includes: [
-        "\"Binding.hpp\"",
-        "\"DUniqueString.hpp\""
-    ],
-    // extra includes in SymbolTable.hpp, if any
-    user_hpp_includes: [],
-    namespace1: "xo",
-    namespace2: "scm",
-    // text after includes, before ASymbolTable
-    pretext: [ "// {pretext} here" ],
-    facet: "SymbolTable",
-    detail_subdir: "symtab",
-    brief: "symbol table derived from a set of schematika expressions",
-    using_doxygen: true,
-    doc: [
-        "Map symbols to schematika expressions. Output of schematika parser"
-    ],
-    types: [
-        // { name: string, doc: [ string ], definition: string },
-    ],
-    const_methods: [
-
-        {
-            // bool is_global_symtab() const noexcept;
-            name: "is_global_symtab",
-            doc: ["true iff this is toplevel (global) symbol table."],
-            return_type: "bool",
-            args: [],
-            const: true,
-            noexcept: true,
-            attributes: [],
-        },
-
-        {
-            // Binding lookup_binding(const DUniqueString * sym) const noexcept;
-            name: "lookup_binding",
-            doc: ["report ingredients needed to address variable at runtime."],
-            return_type: "Binding",
-            args: [
-                {type: "const DUniqueString *", name: "sym"},
-            ],
-            const: true,
-            noexcept: true,
-            attributes: [],
-        },
-
-        // //
-        // obj<AExpression> lookup_var(const DUniqueString * sym) const noexcept;
-
-        // //
-        // obj<AExpression> lookup_local(const DUniqueString * sym) const noexcept;
-    ],
-    nonconst_methods: [
-        // // Variable gives both {name, type}
-        // void upsert_local(DVariable * target) = 0;
-    ],
-    router_facet_explicit_content: [ ],
-}

idl/SyntaxStateMachine.json5

@@ -0,0 +1,160 @@
+{
+    mode: "facet",
+    output_cpp_dir: "src/reader2",
+    output_hpp_dir: "include/xo/reader2",
+    output_impl_subdir: "ssm",
+    // includes in ASyntaxStateMachine.hpp
+    includes: [
+        "\"ParserStateMachine.hpp\"",
+        "\"syntaxstatetype.hpp\"",
+        "<xo/type/Type.hpp>",
+        "<xo/tokenizer2/Token.hpp>",
+        "<xo/reflect/TypeDescr.hpp>",
+        "<xo/alloc2/GCObjectVisitor.hpp>"
+    ],
+    // extra includes in SyntaxStateMachine.hpp, if any
+    user_hpp_includes: [],
+    namespace1: "xo",
+    namespace2: "scm",
+    // text after includes, before ASyntaxStateMachine
+    pretext: ["// {pretext} here"],
+    facet: "SyntaxStateMachine",
+    detail_subdir: "ssm",
+    brief: "specialized state machine for parsing some particular schematika syntax",
+    using_doxygen: true,
+    doc: [
+        "Assistant to schematika parser dedicated to particular syntax"
+    ],
+    types: [
+        { name: "TypeDescr", doc: [ "reflected c++ type" ], definition: "xo::reflect::TypeDescr" },
+        { name: "AGCObjectVisitor", doc: [ "gc visitor interface" ], definition: "xo::mm::AGCObjectVisitor" },
+        { name: "AGCObject", doc: [ "gc-aware object" ], definition: "xo::mm::AGCObject" },
+        { name: "VisitReason", doc: [ "hint when traversing gco graph" ], definition: "xo::mm::VisitReason" },
+    ],
+    const_methods: [
+        {
+            name: "ssm_type",
+            doc: ["identify a type of syntax state machine"],
+            return_type: "syntaxstatetype",
+            args: [],
+            const: true,
+            noexcept: true,
+            attributes: [],
+        },
+        {
+            name: "get_expect_str",
+            doc: ["text describing expected/allowed input to this ssm in current state"],
+            return_type: "std::string_view",
+            args: [],
+            const: true,
+            noexcept: true,
+            attributes: [],
+        },
+    ],
+    nonconst_methods: [
+        {
+            name: "on_token",
+            doc: ["operate state machine for incoming token @p tk"],
+            return_type: "void",
+            args: [
+                {type: "const Token &", name: "tk"},
+                {type: "ParserStateMachine *", name: "p_psm"},
+            ],
+        },
+        {
+            name: "on_parsed_symbol",
+            doc: ["update  stat machine for incoming parsed symbol @p sym"],
+            return_type: "void",
+            args: [
+                {type: "std::string_view", name: "sym"},
+                {type: "ParserStateMachine *", name: "p_psm"},
+            ],
+        },
+        {
+            name: "on_parsed_typedescr",
+            doc: ["operate state machine for incoming type description @p td"],
+            return_type: "void",
+            args: [
+                {type: "TypeDescr", name: "td"},
+                {type: "ParserStateMachine *", name: "p_psm"},
+            ],
+        },
+        {
+            name: "on_parsed_type",
+            doc: ["update state machine for type emitted by nested ssm"],
+            return_type: "void",
+            args: [
+                {type: "obj<AType>", name: "type"},
+                {type: "ParserStateMachine *", name: "p_psm"},
+            ],
+        },
+        {
+            name: "on_parsed_formal",
+            doc: ["operate state machine for formal emitted by nested ssm"],
+            return_type: "void",
+            args: [
+                {type: "const DUniqueString *", name: "param_name"},
+                {type: "TypeDescr", name: "param_type"},
+                {type: "ParserStateMachine *", name: "p_psm"},
+            ],
+        },
+        {
+            name: "on_parsed_formal_with_token",
+            doc: ["operate state machine for formal emitted by nested ssm"],
+            return_type: "void",
+            args: [
+                {type: "const DUniqueString *", name: "param_name"},
+                {type: "TypeDescr", name: "param_type"},
+                {type: "const Token &", name: "tk"},
+                {type: "ParserStateMachine *", name: "p_psm"},
+            ],
+        },
+        {
+            name: "on_parsed_formal_arglist",
+            doc: ["consume formal arglist emitted by nested ssm"],
+            return_type: "void",
+            args: [
+                {type: "DArray *", name: "arglist"},
+                {type: "ParserStateMachine *", name: "p_psm"},
+            ],
+        },
+        {
+            name: "on_parsed_expression",
+            doc: ["update state machine for nested parsed expression @p expr"],
+            return_type: "void",
+            args: [
+                {type: "obj<AExpression>", name: "expr"},
+                {type: "ParserStateMachine *", name: "p_psm"},
+            ],
+        },
+        {
+            name: "on_parsed_expression_with_token",
+            doc: ["update state machine @p p_psm for incoming parsed expression @p expr followed by token @p tk"],
+            return_type: "void",
+            args: [
+                {type: "obj<AExpression>", name: "expr"},
+                {type: "const Token &", name: "tk"},
+                {type: "ParserStateMachine *", name: "p_psm"},
+            ],
+        },
+        {
+            name: "on_quoted_literal",
+            doc: ["update state machine for nested quoted literal @p lit"],
+            return_type: "void",
+            args: [
+                {type: "obj<AGCObject>", name: "lit"},
+                {type: "ParserStateMachine *", name: "p_psm"},
+            ],
+        },
+        {
+            name: "visit_gco_children",
+            doc: ["gc support: visit immediate gc-aware child pointers with @p gc.  Call gc.visit_child() for each"],
+            return_type: "void",
+            args: [
+                {type: "VisitReason", name: "reason"},
+                {type: "obj<AGCObjectVisitor>", name: "gc"},
+            ],
+        }
+    ],
+    router_facet_explicit_content: [ ],
+}

include/xo/expression2/ApplyExpr.hpp

@@ -1,13 +0,0 @@
-/** @file ApplyExpr.hpp
- *
- *  @author Roland Conybeare, Feb 2026
- **/
-
-#pragma once
-
-#include "DApplyExpr.hpp"
-#include "detail/IExpression_DApplyExpr.hpp"
-#include "detail/IGCObject_DApplyExpr.hpp"
-#include "detail/IPrintable_DApplyExpr.hpp"
-
-/* end ApplyExpr.hpp */

include/xo/expression2/Binding.hpp

@@ -1,65 +0,0 @@
-/** @file Binding.hpp
- *
- *  @author Roland Conybeare, Jan 2026
- **/
-
-#pragma once
-
-#include <iostream>
-#include <cstdint>
-
-namespace xo {
-    namespace scm {
-        class Binding {
-        public:
-            using slot_type = int32_t;
-
-            static constexpr int32_t c_link_sentinel = -2;
-            static constexpr int32_t c_link_global = -1;
-
-        public:
-            Binding() : i_link_{-2}, j_slot_{-1} {}
-            Binding(int32_t i_link, int32_t j_slot)
-                : i_link_{i_link}, j_slot_{j_slot} {}
-
-            static Binding null() { return Binding(); }
-            /** global bindings are located by symbol name **/
-            static Binding global(int32_t j_slot) { return Binding(c_link_global, j_slot); }
-            static Binding local(int32_t j_slot) { return Binding(0, j_slot); }
-            static Binding relative(int32_t i_link, Binding def);
-
-            bool is_null() const {
-                return (i_link_ == c_link_sentinel) && (j_slot_ == -1);
-            }
-            bool is_global() const { return i_link_ == c_link_global; }
-            bool is_local() const { return (i_link_ == 0) && (j_slot_ >= 0); }
-
-            int32_t i_link() const noexcept { return i_link_; }
-            int32_t j_slot() const noexcept { return j_slot_; }
-
-            /** print human-readable repr to stream @p os **/
-            void print(std::ostream & os) const;
-
-        private:
-            /**
-             *  >= 0: number of parent links to traverse
-             *        to a fixed-size frame
-             *    -1: resolve globally
-             *    -2: sentinel (binding info not computed)
-             **/
-            int32_t i_link_ = c_link_sentinel;
-            /** if @ref i_link_ >= 0, frame offset
-             *  (in 'variables' not bytes).
-             *  ignored if @ref i_link_ is global
-             **/
-            int32_t j_slot_ = -1;
-        };
-
-        inline std::ostream & operator<< (std::ostream & os, Binding x) {
-            x.print(os);
-            return os;
-        }
-    } /*namespace scm*/
-} /*namespace xo*/
-
-/* Binding.hpp */

include/xo/expression2/Constant.hpp

@@ -1,13 +0,0 @@
-/** @file Constant.hpp
- *
- *  @author Roland Conybeare, Feb 2026
- **/
-
-#pragma once
-
-#include "DConstant.hpp"
-#include "detail/IExpression_DConstant.hpp"
-#include "detail/IGCObject_DConstant.hpp"
-#include "detail/IPrintable_DConstant.hpp"
-
-/* end Constant.hpp */

include/xo/expression2/DApplyExpr.hpp

@@ -1,113 +0,0 @@
-/** @file DApplyExpr.hpp
- *
- *  @author Roland Conybeare, Jan 2026
- **/
-
-#pragma once
-
-#include "Expression.hpp"
-#include "TypeRef.hpp"
-#include "exprtype.hpp"
-#include <xo/alloc2/GCObjectVisitor.hpp>
-#include <xo/object2/DArray.hpp>
-#include <xo/reflect/TypeDescr.hpp>
-#include <xo/indentlog/print/pretty.hpp>
-
-namespace xo {
-    namespace scm {
-
-        /** @class DApplyExpr
-         *  @brief syntax for a procedure/function call
-         **/
-        class DApplyExpr {
-        public:
-            using AGCObjectVisitor = xo::mm::AGCObjectVisitor;
-            using VisitReason = xo::mm::VisitReason;
-            using AAllocator = xo::mm::AAllocator;
-            using TypeDescr = xo::reflect::TypeDescr;
-            using ppindentinfo = xo::print::ppindentinfo;
-            using size_type = std::uint32_t;
-
-        public:
-            /** @defgroup scm-applyexpr-constructors **/
-            ///@{
-
-            /** construct empty instance, but with argument expressions empty **/
-            DApplyExpr(TypeRef typeref,
-                       obj<AExpression> fn_expr,
-                       size_type n_args);
-
-            /** create apply for function with 2 arguments **/
-            static obj<AExpression,DApplyExpr> make2(obj<AAllocator> mm,
-                                                     TypeRef typeref,
-                                                     obj<AExpression> fn_expr,
-                                                     obj<AExpression> arg1,
-                                                     obj<AExpression> arg2);
-
-            /** create apply for function with 2 arguments **/
-            static DApplyExpr * _make2(obj<AAllocator> mm,
-                                       TypeRef typeref,
-                                       obj<AExpression> fn_expr,
-                                       obj<AExpression> arg1,
-                                       obj<AExpression> arg2);
-
-            /** scaffold incomplete instance.
-             *  apply-expr using memory from @p mm.
-             *  will construct instance with space for @p n_args arguments
-             *  but expressions left empty.
-             *  use @ref assign_arg for all arguments to complete.
-             **/
-            static DApplyExpr * scaffold(obj<AAllocator> mm,
-                                         TypeRef typeref,
-                                         obj<AExpression> fn_expr,
-                                         size_type n_args);
-            void assign_arg(size_type i_arg, obj<AExpression> expr);
-
-            ///@}
-            /** @defgroup scm-applyexpr-access-methods **/
-            ///@{
-
-            obj<AExpression>  fn() const noexcept { return fn_; }
-            size_type n_args() const noexcept { return n_args_; }
-            obj<AExpression> arg(size_type i) const;
-
-            ///@}
-            /** @defgroup scm-applyexpr-expression-facet **/
-            ///@{
-
-            exprtype extype() const noexcept { return exprtype::apply; }
-            TypeRef typeref() const noexcept { return typeref_; }
-            TypeDescr valuetype() const noexcept { return typeref_.td(); }
-            void assign_valuetype(TypeDescr td) noexcept;
-
-            ///@}
-            /** @defgroup scm-applyexpr-gcobject-facet **/
-            ///@{
-
-            DApplyExpr * gco_shallow_move(obj<AGCObjectVisitor> gc) noexcept;
-            void visit_gco_children(VisitReason reason, obj<AGCObjectVisitor> gc) noexcept;
-
-            ///@}
-            /** @defgroup scm-applyexpr-printable-facet **/
-            ///@{
-
-            bool pretty(const ppindentinfo & ppii) const;
-
-            ///@}
-
-        private:
-            /** expression value always has type consistent
-             *  with this description
-             **/
-            TypeRef typeref_;
-            /** expression for function/procedure to invoke **/
-            obj<AExpression> fn_;
-            /** number of arguments (not counting @ref fn_ **/
-            size_type n_args_ = 0;
-            /** args_[i] is expression for i'th argument to @ref fn_ **/
-            obj<AExpression> args_[];
-        };
-    }
-}
-
-/* end DApplyExpr.hpp */

include/xo/expression2/DConstant.hpp

@@ -1,91 +0,0 @@
-/** @file DConstant.hpp
- *
- *  @author Roland Conybeare, Jan 2026
- **/
-
-#pragma once
-
-#include "Expression.hpp"
-#include "TypeRef.hpp"
-#include "exprtype.hpp"
-#include <xo/alloc2/GCObject.hpp>
-#include <xo/alloc2/GCObjectVisitor.hpp>
-#include <xo/reflect/TaggedPtr.hpp>
-
-namespace xo {
-    namespace scm {
-        /** @class DConstant
-         *  @brief Schematika expression respresenting a literal constant
-         **/
-        struct DConstant {
-        public:
-            using TaggedPtr = xo::reflect::TaggedPtr;
-            using TypeDescr = xo::reflect::TypeDescr;
-            using AGCObject = xo::mm::AGCObject;
-            using VisitReason = xo::mm::VisitReason;
-            using AGCObjectVisitor = xo::mm::AGCObjectVisitor;
-            using AAllocator = xo::mm::AAllocator;
-            using typeseq = xo::reflect::typeseq;
-            using ppindentinfo = xo::print::ppindentinfo;
-
-        public:
-            explicit DConstant(obj<AGCObject> value) noexcept;
-
-            /** create isntance
-             *  @p mm     memory allocator
-             *  @p value  literal constant
-             **/
-            static obj<AExpression,DConstant> make(obj<AAllocator> mm,
-                                                   obj<AGCObject> value);
-
-            /** create instance
-             *  @p mm     memory allocator
-             *  @p value  literal constant
-             **/
-            static DConstant * _make(obj<AAllocator> mm,
-                                     obj<AGCObject> value);
-
-            bool is_resolved() const noexcept { return typeref_.is_resolved(); }
-
-            obj<AGCObject> value() const noexcept { return value_; }
-            TypeDescr value_td() const noexcept { return typeref_.td(); }
-            TaggedPtr value_tp() const noexcept { return TaggedPtr(typeref_.td(), value_.data()); }
-
-            /** @defgroup scm-constant-expression-facet **/
-            ///@{
-
-            exprtype extype() const noexcept { return exprtype::constant; }
-            TypeRef typeref() const noexcept { return typeref_; }
-            TypeDescr valuetype() const noexcept { return typeref_.td(); }
-            void assign_valuetype(TypeDescr td) noexcept { typeref_.resolve(td); }
-
-            ///@}
-            /** @defgroup scm-constant-gcobject-facet **/
-            ///@{
-
-            DConstant * gco_shallow_move(obj<AGCObjectVisitor> gc) noexcept;
-            void visit_gco_children(VisitReason reason, obj<AGCObjectVisitor> gc) noexcept;
-
-            ///@}
-            /** @defgroup scm-constant-printable-facet **/
-            ///@{
-
-            bool pretty(const ppindentinfo & ppii) const;
-
-            ///@}
-
-        private:
-            static TypeDescr _lookup_td(typeseq tseq);
-
-        private:
-            /** type for value of this expression
-             *  or unification breadcrumb before unification
-             **/
-            TypeRef typeref_;
-            /** literal value **/
-            obj<AGCObject> value_;
-        };
-    } /*namespace scm*/
-} /*namespace xo*/
-
-/* end DConstant.hpp */

include/xo/expression2/DDefineExpr.hpp

@@ -1,108 +0,0 @@
-/** @file DDefineExpr.hpp
- *
- *  @author Roland Conybeare, Jan 2026
- **/
-
-#pragma once
-
-#include "Expression.hpp"
-#include "DVariable.hpp"
-#include <xo/alloc2/Allocator.hpp>
-#include <xo/alloc2/GCObjectVisitor.hpp>
-#include <xo/indentlog/print/pretty.hpp>
-
-namespace xo {
-    namespace scm {
-        class DUniqueString; // see DUniqueString.hpp
-
-        /** @class DDefineExpr
-         *  @brief an expression that introduces a variable.
-         *
-         *  Variable may optionally be declared with a type,
-         *  and may come with an expression specifying an initial value
-         **/
-        class DDefineExpr {
-        public:
-            using ppindentinfo = xo::print::ppindentinfo;
-            using ACollector = xo::mm::ACollector;
-            using AGCObjectVisitor = xo::mm::AGCObjectVisitor;
-            using VisitReason = xo::mm::VisitReason;
-            using AAllocator = xo::mm::AAllocator;
-            using TypeDescr = xo::reflect::TypeDescr;
-
-        public:
-            /** @defgroup scm-defineexpr-constructors **/
-            ///@{
-
-            /** create instance: define-expr using memory from @p mm
-             *  with lhs name @p lhs_name and rhs expression @p rhs_expr
-             **/
-            static DDefineExpr * make(obj<AAllocator> mm,
-                                      const DUniqueString * lhs_name,
-                                      obj<AExpression> rhs_expr);
-            /** create empty skeleton. Rely on this for parsing
-             **/
-            static DDefineExpr * make_empty(obj<AAllocator> mm);
-
-            DDefineExpr(DVariable * lhs_var,
-                        obj<AExpression> rhs);
-
-            ///@}
-            /** @defgroup scm-definexpr-access-methods **/
-            ///@{
-
-            DVariable * lhs() const { return lhs_var_; }
-            obj<AExpression> rhs() const noexcept { return rhs_; }
-            const DUniqueString * name() const noexcept;
-
-            ///@}
-            /** @defgroup scm-definexpr-bookkeeping-methods **/
-            ///@{
-
-            void assign_lhs_name(const DUniqueString * name);
-            void assign_rhs(obj<AExpression> rhs);
-
-            ///@}
-            /** @defgroup scm-defineexpr-expression-facet **/
-            ///@{
-
-            exprtype extype() const noexcept { return exprtype::define; }
-            TypeRef typeref() const noexcept { return lhs_var_->typeref(); }
-            TypeDescr valuetype() const noexcept { return lhs_var_->typeref().td(); }
-            void assign_valuetype(TypeDescr td) noexcept;
-
-            ///@}
-            /** @defgroup scm-defineexpr-gcobject-facet **/
-            ///@{
-
-            DDefineExpr * gco_shallow_move(obj<AGCObjectVisitor> gc) noexcept;
-            void visit_gco_children(VisitReason reason, obj<AGCObjectVisitor> gc) noexcept;
-
-            ///@}
-            /** @defgroup scm-defineexpr-printable-facet **/
-            ///@{
-
-            bool pretty(const ppindentinfo & ppii) const;
-
-            ///@}
-
-        private:
-            /** @defgrouop scm-defineexpr-instance-vars **/
-            ///@{
-
-            /** variable being defined by this expression.
-             **/
-            DVariable * lhs_var_ = nullptr;
-
-            /** expression for initial value of this expression
-             **/
-            obj<AExpression> rhs_;
-
-            // std::set<std::string> free_var_set_;
-
-            ///@}
-        };
-    } /*namespace scm*/
-} /*namespace xo*/
-
-/* end DDefineExpr.hpp */

include/xo/expression2/DGlobalSymtab.hpp

@@ -1,161 +0,0 @@
-/** @file DGlobalSymtab.hpp
-*
- *  @author Roland Conybeare, Jan 2026
- **/
-
-#pragma once
-
-#include "Binding.hpp"
-#include "DVariable.hpp"
-#include "DTypename.hpp"
-#include <xo/object2/DArray.hpp>
-#include <xo/alloc2/GCObjectVisitor.hpp>
-#include <xo/alloc2/dp.hpp>
-#include <xo/arena/DArenaHashMap.hpp>
-
-namespace xo {
-    namespace scm {
-        class DUniqueString;
-
-        /** @class DGlobalSymtab
-         *  @brief symbol table for toplevel environment
-         *
-         *  We're using DArenaHashMap to store <key,binding> pairs.
-         *  Both of these are outside GC-space, so we don't need collector
-         *  to traverse these.
-         **/
-        class DGlobalSymtab {
-        public:
-            using key_type = const DUniqueString *;
-            using value_type = Binding;
-            using ArenaHashMapConfig = xo::map::ArenaHashMapConfig;
-            using repr_type = xo::map::DArenaHashMap<key_type, Binding::slot_type>;
-            using AGCObject = xo::mm::AGCObject;
-            using AGCObjectVisitor = xo::mm::AGCObjectVisitor;
-            using VisitReason = xo::mm::VisitReason;
-            using AAllocator = xo::mm::AAllocator;
-            using MemorySizeVisitor = xo::mm::MemorySizeVisitor;
-            using ppindentinfo = xo::print::ppindentinfo;
-            using size_type = std::uint32_t;
-
-        public:
-            /** @defgroup scm-globalsymtab-ctors constructors **/
-            ///@{
-
-            DGlobalSymtab(dp<repr_type> var_map, DArray * vars,
-                          dp<repr_type> type_map, DArray * types);
-
-            /** move constructor (needed because dp<> deletes copy ctor) **/
-            DGlobalSymtab(DGlobalSymtab && other);
-
-            /** create instance.
-             *  Use memory from @p fixed_mm for @ref map_.
-             *  Use memory from @p mm for DGlobalSymtab instance.
-             *  Hashmap for variables per @p var_cfg; for types per @p type_cfg.
-             **/
-            static DGlobalSymtab * _make(obj<AAllocator> mm,
-                                         obj<AAllocator> fixed_mm,
-                                         const ArenaHashMapConfig & var_cfg,
-                                         const ArenaHashMapConfig & type_cfg);
-
-            /** like _make(..), but create fop **/
-            static obj<AGCObject,DGlobalSymtab> make(obj<AAllocator> mm,
-                                                     obj<AAllocator> fixed_mm,
-                                                     const ArenaHashMapConfig & var_cfg,
-                                                     const ArenaHashMapConfig & type_cfg);
-
-            /** non-trivial destructor for @ref map_ **/
-            ~DGlobalSymtab() = default;
-
-            ///@}
-            /** @defgroup scm-globalsymtab-access-methods access methods **/
-            ///@{
-
-            size_type n_vars() const noexcept { return var_map_->size(); }
-            size_type var_capacity() const noexcept { return var_map_->capacity(); }
-
-            /** visit symtab-owned memory pools; call visitor(info) for each **/
-            void visit_pools(const MemorySizeVisitor & visitor) const;
-
-            /** lookup global symbol with name @p sym **/
-            DVariable * lookup_variable(const DUniqueString * sym) const noexcept;
-
-            /** lookup global typename with name @p sym **/
-            DTypename * lookup_typename(const DUniqueString * sym) const noexcept;
-
-            ///@}
-            /** @defgroup scm-globalsymtab-general-methods general methods **/
-            ///@{
-
-            /** update this symtab to associate @p var with @c var->name().
-             *  If there was a previous variable with the same name,
-             *  replace it with @p var.
-             **/
-            void upsert_variable(obj<AAllocator> mm,
-                                 DVariable * var);
-
-            /** update this symtab to associate typename @p type with @c type->name().
-             *  If there was a previous type with the same name, replace it with
-             *  @p type.
-             **/
-            void upsert_typename(obj<AAllocator> mm,
-                                 DTypename * type);
-
-            ///@}
-            /** @defgroup scm-globalsymtab-symboltable-facet symboltable facet **/
-            ///@{
-
-            /** true for global symbol table **/
-            bool is_global_symtab() const noexcept { return true; }
-
-            /** lookup binding for variable @p sym **/
-            Binding lookup_binding(const DUniqueString * sym) const noexcept;
-
-            ///@}
-            /** @defgroup scm-globalsymtab-gcobject-facet gcobject facet **/
-            ///@{
-
-            DGlobalSymtab * gco_shallow_move(obj<AGCObjectVisitor> gc) noexcept;
-            void visit_gco_children(VisitReason reason, obj<AGCObjectVisitor> gc) noexcept;
-
-            ///@}
-            /** @defgroup scm-globalsymtab-printable-facet printable facet **/
-            ///@{
-
-            /** pretty-printing support **/
-            bool pretty(const ppindentinfo & ppii) const;
-
-            ///@}
-
-        private:
-            /** map variable symbol -> index into @ref vars_.
-             *  Minor point: storing offsets instead of Variables allows us to:
-             *  omit hash-map iteration during GC.
-             *  Savings when map_ slots sparsely populated.
-             **/
-            dp<repr_type> var_map_;
-
-            /** array of variables.
-             *  When S is a unique-string for a global symbol, then:
-             *  1. var_map_[S] is unique global index i(S) for S.
-             *  2. vars_[i(S)] is variable-expr var(S) for S
-             *  3. var(S)->name == S
-             **/
-            DArray * vars_ = nullptr;
-
-            /** map type name -> index values into @ref types_ **/
-            dp<repr_type> type_map_;
-
-            /** array of types.
-             *  When T is a unique-string for a globally-defined type, then:
-             *  1. type_map_[T] is unique global index i(T) for T.
-             *  2. types_[i(T)] is type type(T) for T
-             *  3. type(T)->name == T
-             **/
-            DArray * types_ = nullptr;
-        };
-
-    } /*namespace scm*/
-} /*namespace xo*/
-
-/* end DGlobalSymtab.hpp */

include/xo/expression2/DIfElseExpr.hpp

@@ -1,248 +0,0 @@
-/** @file DIfElseExpr.hpp
- *
- *  @author Roland Conybeare, Jan 2026
- **/
-
-#pragma once
-
-#include "Expression.hpp"
-#include "TypeRef.hpp"
-#include "exprtype.hpp"
-#include <xo/alloc2/GCObjectVisitor.hpp>
-#include <xo/alloc2/Allocator.hpp>
-#include <string>
-
-namespace xo {
-    namespace scm {
-
-        /** @class DIfExpr
-         *  @brief abstract syntax tree for a function definition
-         **/
-        class DIfElseExpr {
-        public:
-            using AGCObjectVisitor = xo::mm::AGCObjectVisitor;
-            using VisitReason = xo::mm::VisitReason;
-            using AAllocator = xo::mm::AAllocator;
-            using TypeDescr = xo::reflect::TypeDescr;
-            using ppindentinfo = xo::print::ppindentinfo;
-
-        public:
-            /** @defgroup scm-ifelseexpr-constructors **/
-            ///@{
-
-            /**
-             *  @p ifexpr_type  type for value produced by if-expression.
-             *                  same as both when_true->valuetype() and
-             *                  when_false->valuetype().
-             *  @p test   test-expression;  always execute
-             *  @p when_true  then-branch;  executes only when test succeeds
-             *  @p when_false else-branch;  executes only when test fails
-             **/
-            DIfElseExpr(TypeRef ifexpr_type,
-                        obj<AExpression> test_expr,
-                        obj<AExpression> when_true,
-                        obj<AExpression> when_false);
-
-            /** create if-else expression using memory from @p mm.
-             *  @p when_false can be null
-             **/
-            static obj<AExpression,DIfElseExpr> make(obj<AAllocator> mm,
-                                                     obj<AExpression> test,
-                                                     obj<AExpression> when_true,
-                                                     obj<AExpression> when_false);
-
-            /** create expression for conditional execution of
-             *  @p when_true or @p when_false, depending on result
-             *  of evaluating expression @p test
-             **/
-            static DIfElseExpr * _make(obj<AAllocator> mm,
-                                       obj<AExpression> test,
-                                       obj<AExpression> when_true,
-                                       obj<AExpression> when_false);
-
-            /** create empty if-else expression using memory from @p mm **/
-            static obj<AExpression,DIfElseExpr> make_empty(obj<AAllocator> mm);
-
-            /** create empty if-else expression using memory from @p mm **/
-            static DIfElseExpr * _make_empty(obj<AAllocator> mm);
-
-            ///@}
-            /** @defgroup scm-ifelseexpr-access-methods **/
-            ///@{
-
-            obj<AExpression> test() const noexcept { return test_; }
-            obj<AExpression> when_true() const noexcept { return when_true_; }
-            obj<AExpression> when_false() const noexcept { return when_false_; }
-
-            void assign_test(obj<AExpression> x) { this->test_ = x; }
-            void assign_when_true(obj<AExpression> x) { this->when_true_ = x; }
-            void assign_when_false(obj<AExpression> x) { this->when_false_ = x; }
-
-            ///@}
-            /** @defgroup scm-ifelseexpr-expression-facet **/
-            ///@{
-
-            exprtype extype() const noexcept { return exprtype::ifexpr; }
-            TypeRef typeref() const noexcept { return typeref_; }
-            TypeDescr valuetype() const noexcept { return typeref_.td(); }
-            void assign_valuetype(TypeDescr td) noexcept;
-
-            ///@}
-            /** @defgroup scm-ifelseexpr-printable-facet **/
-            ///@{
-
-            bool pretty(const ppindentinfo & ppii) const;
-
-            ///@}
-            /** @defgroup scm-ifelseexpr-gcobject-facet **/
-            ///@{
-
-            DIfElseExpr * gco_shallow_move(obj<AGCObjectVisitor> gc) noexcept;
-            void visit_gco_children(VisitReason reason, obj<AGCObjectVisitor> gc) noexcept;
-
-            ///@}
-
-#ifdef NOT_YET
-            virtual std::set<std::string> get_free_variables() const override {
-                std::set<std::string> retval = test_->get_free_variables();
-
-                std::set<std::string> free_vars;
-                free_vars = when_true_->get_free_variables();
-                for (const auto & s : free_vars)
-                    retval.insert(s);
-
-                free_vars = when_false_->get_free_variables();
-                for (const auto & s : free_vars)
-                    retval.insert(s);
-
-                return retval;
-            }
-
-            virtual std::size_t visit_preorder(VisitFn visitor_fn) override {
-                std::size_t n = 1;
-
-                visitor_fn(this);
-
-                n += this->test_->visit_preorder(visitor_fn);
-                n += this->when_true_->visit_preorder(visitor_fn);
-                n += this->when_false_->visit_preorder(visitor_fn);
-
-                return n;
-            }
-
-            virtual std::size_t visit_layer(VisitFn visitor_fn) override {
-                std::size_t n = 1;
-
-                visitor_fn(this);
-
-                n += this->test_->visit_layer(visitor_fn);
-                n += this->when_true_->visit_layer(visitor_fn);
-                n += this->when_false_->visit_layer(visitor_fn);
-
-                return n;
-            }
-
-            virtual rp<Expression> xform_layer(TransformFn xform_fn) override {
-                this->test_ = this->test_->xform_layer(xform_fn);
-                this->when_true_ = this->when_true_->xform_layer(xform_fn);
-                this->when_false_= this->when_false_->xform_layer(xform_fn);
-
-                return xform_fn(this);
-            }
-
-            virtual void attach_envs(bp<SymbolTable> p) override {
-                test_->attach_envs(p);
-                when_true_->attach_envs(p);
-                when_false_->attach_envs(p);
-            }
-#endif
-
-#ifdef NOT_USING
-            virtual std::int32_t find_free_vars(std::set<bp<Variable>> * p_set) override {
-                return (test_->find_free_vars(p_set)
-                        + when_true_->find_free_vars(p_set)
-                        + when_false_->find_free_vars(p_set));
-            }
-#endif
-
-#ifdef NOPE
-            virtual void display(std::ostream & os) const override;
-            virtual std::uint32_t pretty_print(const ppindentinfo & ppi) const override;
-#endif
-
-        protected:
-#ifdef NOT_YET
-            /**
-             *  @p ifexpr_type  type for value produced by if-expression.
-             *                  same as both when_true->valuetype() and
-             *                  when_false->valuetype().
-             *  @p test   test-expression;  always execute
-             *  @p when_true  then-branch;  executes only when test succeeds
-             *  @p when_false else-branch;  executes only when test fails
-             **/
-            IfExpr(TypeDescr ifexpr_type,
-                   rp<Expression> test,
-                   rp<Expression> when_true,
-                   rp<Expression> when_false)
-                : Expression(exprtype::ifexpr, ifexpr_type),
-                  test_{std::move(test)},
-                  when_true_{std::move(when_true)},
-                  when_false_{std::move(when_false)} {}
-
-            static TypeDescr check_consistent_valuetype(const rp<Expression> & when_true,
-                                                        const rp<Expression> & when_false);
-
-            /** determine if-expr valuetype **/
-            void establish_valuetype();
-#endif
-
-        private:
-            /** expression value always has type consistent
-             *  with this description
-             **/
-            TypeRef typeref_;
-            /** if:
-             *    (if x y z)
-             *
-             *  executes x;  if true execute y; otherwise execute z
-             **/
-            obj<AExpression> test_;
-            obj<AExpression> when_true_;
-            obj<AExpression> when_false_;
-        }; /*IfExpr*/
-
-#ifdef NOPE
-        inline rp<IfExpr>
-        make_ifexpr(const rp<Expression> & test,
-                    const rp<Expression> & when_true,
-                    const rp<Expression> & when_false)
-        {
-            return IfExpr::make(test, when_true, when_false);
-        }
-
-        class IfExprAccess : public IfExpr {
-        public:
-            static rp<IfExprAccess> make(rp<Expression> test,
-                                         rp<Expression> when_true,
-                                         rp<Expression> when_false);
-            static rp<IfExprAccess> make_empty();
-
-            void assign_test(rp<Expression> x) { test_ = std::move(x); }
-            void assign_when_true(rp<Expression> x);
-            void assign_when_false(rp<Expression> x);
-
-        private:
-            IfExprAccess(TypeDescr ifexpr_type,
-                         rp<Expression> test,
-                         rp<Expression> when_true,
-                         rp<Expression> when_false)
-                : IfExpr(ifexpr_type,
-                         std::move(test),
-                         std::move(when_true),
-                         std::move(when_false)) {}
-        };
-#endif
-    } /*namespace scm*/
-} /*namespace xo*/
-
-/* end DIfElseExpr.hpp */

include/xo/expression2/DLambdaExpr.hpp

@@ -1,133 +0,0 @@
-/** @file DLambdaExpr.hpp
- *
- *  @author Roland Conybeare, Jan 2026
- **/
-
-#pragma once
-
-#include "Expression.hpp"
-#include "TypeRef.hpp"
-#include "exprtype.hpp"
-#include "DLocalSymtab.hpp"
-#include "DString.hpp"
-#include <xo/alloc2/GCObjectVisitor.hpp>
-#include <xo/facet/obj.hpp>
-
-namespace xo {
-    namespace scm {
-        /** @class DLambdaExpr
-         *  @brief syntax tree for a function/procedure definition
-         *
-         **/
-        class DLambdaExpr {
-        public:
-            using AGCObjectVisitor = xo::mm::AGCObjectVisitor;
-            using VisitReason = xo::mm::VisitReason;
-            using AAllocator = xo::mm::AAllocator;
-            using TypeDescr = xo::reflect::TypeDescr;
-            using ppindentinfo = xo::print::ppindentinfo;
-            using size_type = DLocalSymtab::size_type;
-
-        public:
-
-            /** @defgroup scm-lambdaexpr-ctors **/
-            ///@{
-
-            DLambdaExpr(TypeRef typeref,
-                        const DUniqueString * name,
-                        DLocalSymtab * local_symtab,
-                        obj<AExpression> body);
-
-            /** create instance using memory from @p mm **/
-            static obj<AExpression,DLambdaExpr> make(obj<AAllocator> mm,
-                                                     TypeRef typeref,
-                                                     const DUniqueString * name,
-                                                     DLocalSymtab * local_symtab,
-                                                     obj<AExpression> body);
-
-            /** create instance, using memory from @p mm **/
-            static DLambdaExpr * _make(obj<AAllocator> mm,
-                                       TypeRef typeref,
-                                       const DUniqueString * name,
-                                       DLocalSymtab * local_symtab,
-                                       obj<AExpression> body);
-
-            /** create type description for lambda with arguments described by @p symtab
-             *  and return type @p return_td.
-             *  Load-bearing for DLambdaSsm in xo-reader2/
-             **/
-            static TypeDescr assemble_lambda_td(DLocalSymtab * symtab,
-                                                TypeDescr return_td);
-
-            ///@}
-            /** @defgroup scm-lambdaexpr-methods **/
-            ///@{
-
-            DLocalSymtab * local_symtab() const noexcept { return local_symtab_; }
-            size_type n_args() const noexcept { return local_symtab_->n_vars(); }
-            obj<AExpression> body_expr() const noexcept { return body_expr_; }
-
-            // get_free_variables()
-            // visit_preorder()
-            // visit_layer()
-            // xform_layer()
-            // attach_envs(SymbolTable*)
-
-            ///@}
-            /** @defgroup scm-lambdaexpr-expression-facet **/
-            ///@{
-
-            exprtype extype() const noexcept;
-            TypeRef typeref() const noexcept;
-            TypeDescr valuetype() const noexcept;
-            void assign_valuetype(TypeDescr td) noexcept;
-
-            ///@}
-            /** @defgroup scm-lambdaexpr-gcobject-facet **/
-            ///@{
-
-            std::size_t shallow_size() const noexcept;
-            DLambdaExpr * gco_shallow_move(obj<AGCObjectVisitor> gc) noexcept;
-            void visit_gco_children(VisitReason reason, obj<AGCObjectVisitor> gc) noexcept;
-
-            ///@}
-            /** @defgroup scm-lambdaexpr-printable-facet **/
-            ///@{
-
-            bool pretty(const ppindentinfo & ppii) const;
-
-            ///@}
-
-        private:
-            /** expression value always has type consistent
-             *  with description here
-             **/
-            TypeRef typeref_;
-
-            /** name for this lambda (generated if necessary) **/
-            const DUniqueString * name_ = nullptr;
-
-#ifdef NOT_YET // when enabled, need to visit forward_children()
-            /** e.g.
-             *    i64(f64,string)
-             *  for function of two arguments with types (f64, string) respectively,
-             *  that returns an i64.
-             **/
-            const DUniqueString * type_name_str_ = nullptr;
-#endif
-
-            /** symbol table for lambda arguments **/
-            DLocalSymtab * local_symtab_ = nullptr;;
-
-            /** expression for function body **/
-            obj<AExpression> body_expr_;
-
-            // free_var_set
-            // captured_var_set
-            // layer_var_map
-            // nested_lambda_map
-        };
-    } /*namespace scm*/
-} /*namespace xo*/
-
-/* end DLambdaExpr.hpp */

include/xo/expression2/DLocalSymtab.hpp

@@ -1,128 +0,0 @@
-/** @file DLocalSymtab.hpp
- *
- *  @author Roland Conybeare, Jan 2026
- **/
-
-#pragma once
-
-#include "Binding.hpp"
-#include "DVariable.hpp"
-#include "DUniqueString.hpp"
-#include <xo/object2/DArray.hpp>
-#include <xo/alloc2/GCObjectVisitor.hpp>
-
-namespace xo {
-    namespace scm {
-        /** @class DLocalSymtab
-         *  @brief symbol table for a local stack frame
-         **/
-        struct DLocalSymtab {
-        public:
-            using DArray = xo::scm::DArray;
-            using ppindentinfo = xo::print::ppindentinfo;
-            using AGCObject = xo::mm::AGCObject;
-            using VisitReason = xo::mm::VisitReason;
-            using AGCObjectVisitor = xo::mm::AGCObjectVisitor;
-            using AAllocator = xo::mm::AAllocator;
-            /* note: uint16_t would be fine too */
-            using size_type = std::uint32_t;
-
-            struct Slot {
-                Slot() = default;
-                explicit Slot(DVariable * var) : var_{var} {}
-
-                /** variable representing a formal argument.
-                 *  binding will be correct only within the same layer
-                 *  as top-level lambda body
-                 *  (i.e. up to the doorstep of each and every nested lambda)
-                 **/
-                DVariable * var_ = nullptr;
-            };
-
-        public:
-            /** @defgroup scm-lambdaexpr-constructors **/
-            ///@{
-
-            /** empty instance with parent @p p, using arrays @p vars for variables
-             *  and @p types for type definitions.
-             **/
-            DLocalSymtab(DLocalSymtab * p, DArray * nv, DArray * nt);
-
-            /** scaffold empty symtab instance,
-             *  capacity for @p nv vars and @p nt types,
-             *  using memory from allocator @p mm.
-             *  Symtab chains to parent @p p.
-             **/
-            static DLocalSymtab * _make_empty(obj<AAllocator> mm,
-                                              DLocalSymtab * p,
-                                              size_type nv,
-                                              size_type nt);
-
-            ///@}
-            /** @defgroup scm-lambdaexpr-methods **/
-            ///@{
-
-            DLocalSymtab * parent() const noexcept { return parent_; }
-            //size_type capacity() const noexcept { return capacity_; }
-            size_type n_vars() const noexcept { return vars_->size(); }
-            size_type n_types() const noexcept { return types_->size(); }
-
-            DVariable * lookup_var(Binding ix) noexcept;
-
-            /** increase slot size (provided below capacity) to append
-             *  binding for one local variable.  Local variable will be allocated
-             *  from @p mm, named @p name, with type described by @p typeref.
-             **/
-            Binding append_var(obj<AAllocator> mm,
-                               const DUniqueString * name,
-                               TypeRef typeref);
-
-            /** increase slot size (provided below capacity) to append
-             *  binding for one local type.  Local type will be allocated
-             *  from @p mm, named @p name, with type described by @p type.
-             **/
-            void append_type(obj<AAllocator> mm,
-                             const DUniqueString * name,
-                             obj<AType> type);
-
-            ///@}
-            /** @defgroup xo-localsymtab-symboltable-facet symboltable facet**/
-            ///@{
-
-            /** true for global symbol table **/
-            bool is_global_symtab() const noexcept { return false; }
-
-            /** lookup binding for variable @p sym **/
-            Binding lookup_binding(const DUniqueString * sym) const noexcept;
-
-            ///@}
-            /** @defgroup xo-localsymtab-gcobject-facet gcobject facet **/
-            ///@{
-
-            DLocalSymtab * gco_shallow_move(obj<AGCObjectVisitor> gc) noexcept;
-            void visit_gco_children(VisitReason reason, obj<AGCObjectVisitor> gc) noexcept;
-
-            ///@}
-            /** @defgroup xo-localsymtab-printable-facet printable facet **/
-            ///@{
-
-            bool pretty(const ppindentinfo & ppii) const;
-
-            ///@}
-
-        private:
-            /** parent symbol table from scoping surrounding this one **/
-            DLocalSymtab * parent_ = nullptr;
-            /** variables owned by (declared in) this symbol table
-             *   vars_[i] is convertible to obj<AGCObject>
-             **/
-            DArray * vars_ = nullptr;
-            /** types owned by (defined in) this symbol table
-             *   types_[i] is convertible to obj<AType>
-             **/
-            DArray * types_ = nullptr;
-        };
-    } /*namespace scm*/
-} /*namespace xo*/
-
-/* end DLocalSymtab.hpp */

include/xo/expression2/DSequenceExpr.hpp

@@ -1,93 +0,0 @@
-/** @file DSequenceExpr.hpp
- *
- *  @author Roland Conybeare, Jan 2026
- **/
-
-#pragma once
-
-#include "Expression.hpp"
-#include "TypeRef.hpp"
-#include <xo/object2/DArray.hpp>
-#include <xo/alloc2/GCObjectVisitor.hpp>
-
-namespace xo {
-    namespace scm {
-
-        /** syntax for a sequence of expressions
-         *   {
-         *      expr(1);
-         *      expr(2);
-         *      ...
-         *      expr(n);
-         *   }
-         **/
-        class DSequenceExpr {
-        public:
-            using AGCObjectVisitor = xo::mm::AGCObjectVisitor;
-            using VisitReason = xo::mm::VisitReason;
-            using AAllocator = xo::mm::AAllocator;
-            using TypeDescr = xo::reflect::TypeDescr;
-            using size_type = DArray::size_type;
-            using ppindentinfo = xo::print::ppindentinfo;
-
-        public:
-            DSequenceExpr() ;
-            DSequenceExpr(DArray * xv);
-
-            /** create empty sequence using memory from @p mm **/
-            static obj<AExpression,DSequenceExpr> make_empty(obj<AAllocator> mm);
-
-            /** create empty sequence expression using mmeory from @p mm **/
-            static DSequenceExpr * _make_empty(obj<AAllocator> mm);
-
-            size_type size() const noexcept;
-            obj<AExpression> operator[](std::size_t i) const;
-
-            /** append @p expr to the end of this sequence;
-             *  use memory from @p mm if need to expand storage
-             **/
-            void push_back(obj<AAllocator> mm,
-                           obj<AExpression> expr);
-
-            // get_free_variables();
-            // visit_preorder();
-            // visit_layer();
-            // xform_layer()
-            // attach_envs()
-
-            /** @defgroup scm-ifelseexpr-expression-facets **/
-            ///@{
-
-            exprtype extype() const noexcept { return exprtype::sequence; }
-            TypeRef typeref() const noexcept { return typeref_; }
-            TypeDescr valuetype() const noexcept { return typeref_.td(); }
-            void assign_valuetype(TypeDescr td) noexcept;
-
-            ///@}
-            /** @defgroup scm-sequenceexpr-printable-facet printable facet methods **/
-            ///@{
-
-            /** pretty-printing driver; combine layout+printing **/
-            bool pretty(const ppindentinfo & ppii) const;
-
-            ///@}
-            /** @defgroup scm-sequenceexpr-gcobject-facet gcobject facet methods **/
-            ///@{
-
-            DSequenceExpr * gco_shallow_move(obj<AGCObjectVisitor> gc) noexcept;
-            void visit_gco_children(VisitReason reason, obj<AGCObjectVisitor> gc) noexcept;
-
-            ///@}
-
-        private:
-            /** expression value always has type consistent with this description
-             **/
-            TypeRef typeref_;
-            /** array of expressions **/
-            DArray * expr_v_ = nullptr;
-        };
-
-    } /*namespace scm*/
-} /*namespace xo*/
-
-/* end DSequenceExpr.hpp */

include/xo/expression2/DTypename.hpp

@@ -1,78 +0,0 @@
-/** @file DTypename.hpp
- *
- *  @author Roland Conybeare, Mar 2026
- **/
-
-#pragma once
-
-#include "DUniqueString.hpp"
-#include <xo/type/Type.hpp>
-#include <xo/alloc2/GCObjectVisitor.hpp>
-#include <xo/printable2/Printable.hpp>
-#include <xo/indentlog/print/pretty.hpp>
-
-namespace xo {
-    namespace scm {
-
-        /** @class DTypename
-         *  @brief Container for a named type
-         *
-         *  Represents the result of syntax like
-         *  1. deftype Foo :: i64;
-         *  2. deftype FooAlias :: Foo;
-         **/
-        class DTypename {
-        public:
-            using ppindentinfo = xo::print::ppindentinfo;
-            using AGCObjectVisitor = xo::mm::AGCObjectVisitor;
-            using VisitReason = xo::mm::VisitReason;
-            using AGCObject = xo::mm::AGCObject;
-            using AAllocator = xo::mm::AAllocator;
-
-        public:
-            DTypename(const DUniqueString * name,
-                      obj<AType> type);
-
-            /** create instance
-             *  @p mm      memory allocator
-             *  @p name    type name
-             *  @p type    type definition
-             **/
-            static DTypename * _make(obj<AAllocator> mm,
-                                     const DUniqueString * name,
-                                     obj<AType> type);
-            /** create fop for new instance **/
-            static obj<AGCObject,DTypename> make(obj<AAllocator> mm,
-                                                 const DUniqueString * name,
-                                                 obj<AType> type);
-
-            const DUniqueString * name() const noexcept { return name_; }
-            obj<AType> type() const noexcept { return type_; }
-
-            void assign_name(const DUniqueString * name) { this->name_ = name; }
-
-
-            /** @defgroup scm-typename-gcobject-facet **/
-            ///@{
-
-            DTypename * gco_shallow_move(obj<AGCObjectVisitor> gc) noexcept;
-            void visit_gco_children(VisitReason reason, obj<AGCObjectVisitor> gc) noexcept;
-
-            ///@}
-            /** @defgroup scm-typename-printable-facet **/
-            ///@{
-
-            bool pretty(const ppindentinfo & ppii) const;
-
-            ///@}
-
-        private:
-            /** symbol name **/
-            const DUniqueString * name_ = nullptr;
-            /** type defintion.  Everything but the name **/
-            obj<AType> type_;
-        };
-    } /*namespace scm*/
-} /*namespace xo*/
-
-/* end DTypename.hpp */

include/xo/expression2/DVarRef.hpp

@@ -1,85 +0,0 @@
-/** @file DVarRef.hpp
- *
- *  @author Roland Conybeare, Feb 2026
- **/
-
-#pragma once
-
-#include "Variable.hpp"
-#include <xo/alloc2/GCObjectVisitor.hpp>
-
-namespace xo {
-    namespace scm {
-
-        /** @class DVarRef
-         *  @brief syntax for a variable reference
-         *
-         *  Reference to a known variable possibly
-         *  defined in another scope.
-         *  For non-local non-global variables,
-         **/
-        class DVarRef {
-        public:
-            using ppindentinfo = xo::print::ppindentinfo;
-            using AGCObjectVisitor = xo::mm::AGCObjectVisitor;
-            using VisitReason = xo::mm::VisitReason;
-            using AAllocator = xo::mm::AAllocator;
-            using TypeDescr = xo::reflect::TypeDescr;
-
-        public:
-            DVarRef(DVariable * vardef,
-                    Binding path);
-
-            /** create instance
-             *  @p mm      memory allocator
-             *  @p vardef  variable definition (name, typeref, binding)
-             *  @p link    number of lexical scope boundaries we must cross
-             *             to reach scope containing @p vardef.
-             *             Only relevant for non-global vardef
-             **/
-            static DVarRef * make(obj<AAllocator> mm,
-                                  DVariable * vardef,
-                                  int32_t link);
-
-            const DUniqueString * name() const;
-            Binding path() const { return path_; }
-
-            /** @defgroup scm-variable-expression-facet **/
-            ///@{
-
-            exprtype extype() const noexcept { return exprtype::varref; }
-            TypeRef typeref() const noexcept;
-            TypeDescr valuetype() const noexcept;
-            void assign_valuetype(TypeDescr td) noexcept;
-
-            ///@}
-            /** @defgroup scm-variable-gcobject-facet **/
-            ///@{
-
-            DVarRef * gco_shallow_move(obj<AGCObjectVisitor> gc) noexcept;
-            void visit_gco_children(VisitReason reason, obj<AGCObjectVisitor> gc) noexcept;
-
-            ///@}
-            /** @defgroup scm-variable-printable-facet **/
-            ///@{
-
-            bool pretty(const ppindentinfo & ppii) const;
-
-            ///@}
-
-        private:
-            /** variable definition. Created in the sccope where variable introduced.
-             *  Has an associated @ref Binding, but that binding is only correct
-             *  around any nested scopes.
-             **/
-            DVariable * vardef_ = nullptr;
-
-            /** at runtime: navigate environemnt via this path to get
-             *  runtime memory location for this variable
-             **/
-            Binding path_;
-        };
-    } /*namespace scm*/
-} /*namespace xo*/
-
-/* end DVarRef.hpp */

include/xo/expression2/DVariable.hpp

@@ -1,93 +0,0 @@
-/** @file DVariable.hpp
- *
- *  @author Roland Conybeare, Jan 2026
- **/
-
-#pragma once
-
-#include "DUniqueString.hpp"
-#include "Binding.hpp"
-#include "TypeRef.hpp"
-#include "exprtype.hpp"
-#include <xo/alloc2/GCObjectVisitor.hpp>
-#include <xo/reflect/TypeDescr.hpp>
-#include <xo/indentlog/print/pretty.hpp>
-
-namespace xo {
-    namespace scm {
-
-        /** @class DVariable
-         *  @brief syntax for a variable reference
-         **/
-        class DVariable {
-        public:
-            using ppindentinfo = xo::print::ppindentinfo;
-            using AGCObjectVisitor = xo::mm::AGCObjectVisitor;
-            using VisitReason = xo::mm::VisitReason;
-            using AAllocator = xo::mm::AAllocator;
-            using TypeDescr = xo::reflect::TypeDescr;
-
-        public:
-            /** create instance
-             *  @p mm      memory allocator
-             *  @p name    variable name
-             *  @p typeref type information for legal values
-             *             (possibly just placeholder when relying on inference)
-             *  @p path    binding path to runtime value.
-             *             This may be computed after parsing;
-             *             mnust be resolved before execution.
-             **/
-            static DVariable * make(obj<AAllocator> mm,
-                                    const DUniqueString * name,
-                                    const TypeRef & typeref,
-                                    Binding path = Binding());
-
-            DVariable(const DUniqueString * name,
-                      const TypeRef & typeref,
-                      Binding path);
-
-            const DUniqueString * name() const { return name_; }
-            Binding path() const { return path_; }
-
-            void assign_name(const DUniqueString * name) { this->name_ = name; }
-            void assign_path(Binding b) { this->path_ = b; }
-
-            /** @defgroup scm-variable-expression-facet **/
-            ///@{
-
-            exprtype extype() const noexcept { return exprtype::variable; }
-            TypeRef typeref() const noexcept { return typeref_; }
-            TypeDescr valuetype() const noexcept { return typeref_.td(); };
-            void assign_valuetype(TypeDescr td) noexcept;
-
-            ///@}
-            /** @defgroup scm-variable-gcobject-facet **/
-            ///@{
-
-            DVariable * gco_shallow_move(obj<AGCObjectVisitor> gc) noexcept;
-            void visit_gco_children(VisitReason reason, obj<AGCObjectVisitor> gc) noexcept;
-
-            ///@}
-            /** @defgroup scm-variable-printable-facet **/
-            ///@{
-
-            bool pretty(const ppindentinfo & ppii) const;
-
-            ///@}
-
-        private:
-            /** symbol name **/
-            const DUniqueString * name_ = nullptr;
-            /** variable value always has type consistent
-             *  with this description
-             **/
-            TypeRef typeref_;
-            /** at runtime: navigate environemnt via this path to get
-             *  runtime memory location for this variable
-             **/
-            Binding path_;
-        };
-    } /*namespace scm*/
-} /*namespace xo*/
-
-/* end DVariable.hpp */

include/xo/expression2/DefineExpr.hpp

@@ -1,13 +0,0 @@
-/** @file DefineExpr.hpp
- *
- *  @author Roland Conybeare, Feb 2026
- **/
-
-#pragma once
-
-#include "DDefineExpr.hpp"
-#include "detail/IExpression_DDefineExpr.hpp"
-#include "define/IGCObject_DDefineExpr.hpp"
-#include "detail/IPrintable_DDefineExpr.hpp"
-
-/* end DefineExpr.hpp */