xo-reader2 stack: top-level lambda w/ apply parses

src/expression2/Binding.cpp

@@ -0,0 +1,41 @@
+/** @file Binding.cpp
+ *
+ *  @author Roland Conybeare, Feb 2026
+ **/
+
+#include "Binding.hpp"
+#include <cassert>
+
+namespace xo {
+    namespace scm {
+
+        Binding
+        Binding::relative(int32_t i_link, Binding def)
+        {
+            if (def.i_link_ == Binding::c_link_global) {
+                // for globally defined vars, i_link always -1
+                return def;
+            } else if (def.i_link_ >= 0) {
+                return Binding(i_link + def.i_link_, def.j_slot_);
+            } else {
+                assert(false);
+                return Binding();
+            }
+        }
+
+        void
+        Binding::print(std::ostream & os) const
+        {
+            if (i_link_ == c_link_global) {
+                os << "{path:global}";
+            } else if (i_link_ == c_link_sentinel) {
+                os << "{path}";
+            } else {
+                os << "{path:" << i_link_ << ":" << j_slot_ << "}";
+            }
+        }
+
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end Binding.cpp */

src/expression2/CMakeLists.txt

@@ -3,9 +3,12 @@
 set(SELF_LIB xo_expression2)
 set(SELF_SRCS
     init_expression2.cpp
+    expression2_register_facets.cpp
+    expression2_register_types.cpp
 
     DConstant.cpp
     DVariable.cpp
+    DVarRef.cpp
     DDefineExpr.cpp
     DLambdaExpr.cpp
     DApplyExpr.cpp
@@ -13,6 +16,7 @@ set(SELF_SRCS
     DSequenceExpr.cpp
 
     TypeRef.cpp
+    Binding.cpp
 
     IExpression_Any.cpp
 
@@ -24,10 +28,15 @@ set(SELF_SRCS
     IGCObject_DVariable.cpp
     IPrintable_DVariable.cpp
 
+    IExpression_DVarRef.cpp
+    IGCObject_DVarRef.cpp
+    IPrintable_DVarRef.cpp
+
     IExpression_DDefineExpr.cpp
     IPrintable_DDefineExpr.cpp
 
     IExpression_DApplyExpr.cpp
+    IGCObject_DApplyExpr.cpp
     IPrintable_DApplyExpr.cpp
 
     IExpression_DLambdaExpr.cpp
@@ -55,8 +64,6 @@ set(SELF_SRCS
     IGCObject_DUniqueString.cpp
     IPrintable_DUniqueString.cpp
 
-    expression2_register_facets.cpp
-    expression2_register_types.cpp
     )
 
 xo_add_shared_library4(${SELF_LIB} ${PROJECT_NAME}Targets ${PROJECT_VERSION} 1 ${SELF_SRCS})

src/expression2/DApplyExpr.cpp

@@ -102,6 +102,48 @@ namespace xo {
             typeref_.resolve(td);
         }
 
+        // ----- gcobject facet -----
+
+        std::size_t
+        DApplyExpr::shallow_size() const noexcept {
+            return sizeof(DApplyExpr) + (n_args_ * sizeof(obj<AExpression>));
+        }
+
+        DApplyExpr *
+        DApplyExpr::shallow_copy(obj<AAllocator> mm) const noexcept {
+            DApplyExpr * copy = (DApplyExpr *)mm.alloc_copy((std::byte *)this);
+
+            if (copy) {
+                copy->typeref_ = typeref_;
+                copy->fn_ = fn_;
+                copy->n_args_ = n_args_;
+
+                constexpr auto c_obj_z = sizeof(obj<AExpression>);
+
+                ::memcpy((void*)&(copy->args_[0]), (void*)&(args_[0]), n_args_ * c_obj_z);
+            }
+
+            return copy;
+        }
+
+        std::size_t
+        DApplyExpr::forward_children(obj<ACollector> gc) noexcept
+        {
+            for (size_type i = 0; i < n_args_; ++i) {
+                obj<AExpression> & arg = args_[i];
+
+                // runtime poly here
+                obj<AGCObject> arg_gco = arg.to_facet<AGCObject>();
+
+                // need the data address within *this
+                gc.forward_inplace(arg_gco.iface(), (void **)(&arg.data_));
+            }
+
+            return shallow_size();
+        }
+
+        // ----- printable facet -----
+
         bool
         DApplyExpr::pretty(const ppindentinfo & ppii) const {
             using xo::print::ppstate;

src/expression2/DVarRef.cpp

@@ -0,0 +1,105 @@
+/** @file DVarRef.cpp
+ *
+ *  @author Roland Conybeare, Feb 2026
+ **/
+
+#include "DVarRef.hpp"
+
+namespace xo {
+    using xo::mm::AGCObject;
+    using xo::reflect::TypeDescr;
+
+    namespace scm {
+
+        DVarRef::DVarRef(DVariable * vardef,
+                         Binding path)
+                : vardef_{vardef},
+                  path_{path}
+        {}
+
+        DVarRef *
+        DVarRef::make(obj<AAllocator> mm,
+                      DVariable * vardef,
+                      int32_t link)
+        {
+            assert(vardef);
+
+            void * mem = mm.alloc_for<DVarRef>();
+
+            return new (mem) DVarRef(vardef,
+                                     Binding::relative(link,
+                                                       vardef->path()));
+        }
+
+        const DUniqueString *
+        DVarRef::name() const {
+            return vardef_->name();
+        }
+
+        TypeRef
+        DVarRef::typeref() const noexcept {
+            assert(vardef_);
+
+            return vardef_->typeref();
+        }
+
+        TypeDescr
+        DVarRef::valuetype() const noexcept
+        {
+            return this->typeref().td();
+        }
+
+        void
+        DVarRef::assign_valuetype(TypeDescr td) noexcept
+        {
+            assert(vardef_);
+            vardef_->assign_valuetype(td);
+        }
+
+        // gcobject facet
+
+        std::size_t
+        DVarRef::shallow_size() const noexcept
+        {
+            return sizeof(DVarRef);
+        }
+
+        DVarRef *
+        DVarRef::shallow_copy(obj<AAllocator> mm) const noexcept
+        {
+            DVarRef * copy = (DVarRef *)mm.alloc_copy((std::byte *)this);
+
+            if (copy)
+                *copy = *this;
+
+            return copy;
+        }
+
+        std::size_t
+        DVarRef::forward_children(obj<ACollector> gc) noexcept
+        {
+            // TODO: this can be helper in RCollector interface
+            auto iface = xo::facet::impl_for<AGCObject,DVariable>();
+            gc.forward_inplace(&iface, (void **)vardef_);
+
+            // TODO: concept to indicate that no gc pointers in Binding
+
+            return shallow_size();
+        }
+
+        // printable facet
+
+        bool
+        DVarRef::pretty(const ppindentinfo & ppii) const
+        {
+            return ppii.pps()->pretty_struct
+                       (ppii,
+                        "DVarRef",
+                        refrtag("name", std::string_view(*(this->name()))),
+                        refrtag("path", this->path_));
+        }
+
+    }
+} /*namespace xo*/
+
+/* end DVarRef.cpp */

src/expression2/IExpression_DVarRef.cpp

@@ -0,0 +1,45 @@
+/** @file IExpression_DVarRef.cpp
+ *
+ *  Generated automagically from ingredients:
+ *  1. code generator:
+ *       [xo-facet/codegen/genfacet]
+ *     arguments:
+ *       --input [idl/IExpression_DVarRef.json5]
+ *  2. jinja2 template for abstract facet .hpp file:
+ *       [iface_facet_any.hpp.j2]
+ *  3. idl for facet methods
+ *       [idl/IExpression_DVarRef.json5]
+**/
+
+#include "detail/IExpression_DVarRef.hpp"
+
+namespace xo {
+    namespace scm {
+        auto
+        IExpression_DVarRef::extype(const DVarRef & self) noexcept -> exprtype
+        {
+            return self.extype();
+        }
+
+        auto
+        IExpression_DVarRef::typeref(const DVarRef & self) noexcept -> TypeRef
+        {
+            return self.typeref();
+        }
+
+        auto
+        IExpression_DVarRef::valuetype(const DVarRef & self) noexcept -> TypeDescr
+        {
+            return self.valuetype();
+        }
+
+        auto
+        IExpression_DVarRef::assign_valuetype(DVarRef & self, TypeDescr td) noexcept -> void
+        {
+            self.assign_valuetype(td);
+        }
+
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end IExpression_DVarRef.cpp */

src/expression2/IGCObject_DApplyExpr.cpp

@@ -0,0 +1,39 @@
+/** @file IGCObject_DApplyExpr.cpp
+ *
+ *  Generated automagically from ingredients:
+ *  1. code generator:
+ *       [xo-facet/codegen/genfacet]
+ *     arguments:
+ *       --input [idl/IGCObject_DApplyExpr.json5]
+ *  2. jinja2 template for abstract facet .hpp file:
+ *       [iface_facet_any.hpp.j2]
+ *  3. idl for facet methods
+ *       [idl/IGCObject_DApplyExpr.json5]
+**/
+
+#include "detail/IGCObject_DApplyExpr.hpp"
+
+namespace xo {
+    namespace scm {
+        auto
+        IGCObject_DApplyExpr::shallow_size(const DApplyExpr & self) noexcept -> size_type
+        {
+            return self.shallow_size();
+        }
+
+        auto
+        IGCObject_DApplyExpr::shallow_copy(const DApplyExpr & self, obj<AAllocator> mm) noexcept -> Opaque
+        {
+            return self.shallow_copy(mm);
+        }
+
+        auto
+        IGCObject_DApplyExpr::forward_children(DApplyExpr & self, obj<ACollector> gc) noexcept -> size_type
+        {
+            return self.forward_children(gc);
+        }
+
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end IGCObject_DApplyExpr.cpp */

src/expression2/IGCObject_DVarRef.cpp

@@ -0,0 +1,39 @@
+/** @file IGCObject_DVarRef.cpp
+ *
+ *  Generated automagically from ingredients:
+ *  1. code generator:
+ *       [xo-facet/codegen/genfacet]
+ *     arguments:
+ *       --input [idl/IGCObject_DVarRef.json5]
+ *  2. jinja2 template for abstract facet .hpp file:
+ *       [iface_facet_any.hpp.j2]
+ *  3. idl for facet methods
+ *       [idl/IGCObject_DVarRef.json5]
+**/
+
+#include "detail/IGCObject_DVarRef.hpp"
+
+namespace xo {
+    namespace scm {
+        auto
+        IGCObject_DVarRef::shallow_size(const DVarRef & self) noexcept -> size_type
+        {
+            return self.shallow_size();
+        }
+
+        auto
+        IGCObject_DVarRef::shallow_copy(const DVarRef & self, obj<AAllocator> mm) noexcept -> Opaque
+        {
+            return self.shallow_copy(mm);
+        }
+
+        auto
+        IGCObject_DVarRef::forward_children(DVarRef & self, obj<ACollector> gc) noexcept -> size_type
+        {
+            return self.forward_children(gc);
+        }
+
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end IGCObject_DVarRef.cpp */

src/expression2/IPrintable_DVarRef.cpp

@@ -0,0 +1,28 @@
+/** @file IPrintable_DVarRef.cpp
+ *
+ *  Generated automagically from ingredients:
+ *  1. code generator:
+ *       [xo-facet/codegen/genfacet]
+ *     arguments:
+ *       --input [idl/IPrintable_DVarRef.json5]
+ *  2. jinja2 template for abstract facet .hpp file:
+ *       [iface_facet_any.hpp.j2]
+ *  3. idl for facet methods
+ *       [idl/IPrintable_DVarRef.json5]
+**/
+
+#include "detail/IPrintable_DVarRef.hpp"
+
+namespace xo {
+    namespace scm {
+        auto
+        IPrintable_DVarRef::pretty(const DVarRef & self, const ppindentinfo & ppii) -> bool
+        {
+            return self.pretty(ppii);
+        }
+
+
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end IPrintable_DVarRef.cpp */

src/expression2/expression2_register_facets.cpp

@@ -16,13 +16,13 @@
 #include <xo/expression2/detail/IGCObject_DVariable.hpp>
 #include <xo/expression2/detail/IPrintable_DVariable.hpp>
 
+#include <xo/expression2/VarRef.hpp>
+
 #include <xo/expression2/detail/IExpression_DConstant.hpp>
 #include <xo/expression2/detail/IGCObject_DConstant.hpp>
 #include <xo/expression2/detail/IPrintable_DConstant.hpp>
 
-#include <xo/expression2/detail/IExpression_DApplyExpr.hpp>
-//#include <xo/expression2/detail/IGCObject_DApplyExpr.hpp>
-#include <xo/expression2/detail/IPrintable_DApplyExpr.hpp>
+#include <xo/expression2/ApplyExpr.hpp>
 
 #include <xo/expression2/detail/IExpression_DLambdaExpr.hpp>
 //#include <xo/expression2/detail/IGCObject_DLambdaExpr.hpp>
@@ -63,6 +63,7 @@ namespace xo {
             // Expression
             // +- Constant
             // +- Variable
+            // +- VarRef
             // +- DefineExpr
             // +- ApplyExpr
             // +- LambdaExpr
@@ -77,13 +78,20 @@ namespace xo {
             FacetRegistry::register_impl<AGCObject, DVariable>();
             FacetRegistry::register_impl<APrintable, DVariable>();
 
+            FacetRegistry::register_impl<AExpression, DVarRef>();
+            FacetRegistry::register_impl<AGCObject, DVarRef>();
+            FacetRegistry::register_impl<APrintable, DVarRef>();
+
             FacetRegistry::register_impl<AExpression, DDefineExpr>();
+            //FacetRegistry::register_impl<AGCObject, DDefineExpr>();
             FacetRegistry::register_impl<APrintable, DDefineExpr>();
 
             FacetRegistry::register_impl<AExpression, DApplyExpr>();
+            FacetRegistry::register_impl<AGCObject, DApplyExpr>();
             FacetRegistry::register_impl<APrintable, DApplyExpr>();
 
             FacetRegistry::register_impl<AExpression, DLambdaExpr>();
+            //FacetRegistry::register_impl<AGCObject, DLambdaExpr>();
             FacetRegistry::register_impl<APrintable, DLambdaExpr>();
 
             FacetRegistry::register_impl<AExpression, DIfElseExpr>();
@@ -95,11 +103,13 @@ namespace xo {
             FacetRegistry::register_impl<APrintable, DSequenceExpr>();
 
             FacetRegistry::register_impl<ASymbolTable, DLocalSymtab>();
+            //FacetRegistry::register_impl<AGCObject, DLocalSymtab>();
             FacetRegistry::register_impl<APrintable, DLocalSymtab>();
 
             log && log(xtag("DUniqueString.tseq", typeseq::id<DUniqueString>()));
             log && log(xtag("DDefineExpr.tseq", typeseq::id<DDefineExpr>()));
             log && log(xtag("DVariable.tseq", typeseq::id<DVariable>()));
+            log && log(xtag("DVarRef.tseq", typeseq::id<DVarRef>()));
             log && log(xtag("DConstant.tseq", typeseq::id<DConstant>()));
             log && log(xtag("DApplyExpr.tseq", typeseq::id<DApplyExpr>()));
             log && log(xtag("DLambdaExpr.tseq", typeseq::id<DLambdaExpr>()));
@@ -108,7 +118,7 @@ namespace xo {
 
             log && log(xtag("DLocalSymtab.tseq", typeseq::id<DLocalSymtab>()));
 
-            log && log(xtag("AExpression.tqseq", typeseq::id<AExpression>()));
+            log && log(xtag("AExpression.tseq", typeseq::id<AExpression>()));
             log && log(xtag("ASymbolTable.tseq", typeseq::id<ASymbolTable>()));
 
             return true;