xo-reader2 stack: + xo-numeric + setup multi dispatch for *,/

CMakeLists.txt

@@ -99,11 +99,11 @@ add_subdirectory(xo-callback)
 add_subdirectory(xo-printable2)  # experiment w/ facet object model
 add_subdirectory(xo-alloc)
 add_subdirectory(xo-alloc2)   # experiment w/ facet object model
-add_subdirectory(xo-numeric)  # experiment w/ facet object model
 add_subdirectory(xo-gc)
 add_subdirectory(xo-object)
 add_subdirectory(xo-object2)  # experiment w/ facet object model
 add_subdirectory(xo-procedure2)  # schematika procedure abstraction + runtime context (fomo)
+add_subdirectory(xo-numeric)  # experiment w/ facet object model
 add_subdirectory(xo-ordinaltree)
 #
 add_subdirectory(xo-tokenizer2)  # schematika tokenizer (fomo)

xo-facet/include/xo/facet/FacetRegistry.hpp

@@ -50,7 +50,8 @@ namespace xo {
                     // combine the two seqno values
                     std::size_t h1 = std::hash<int32_t>{}(k.first.seqno());
                     std::size_t h2 = std::hash<int32_t>{}(k.second.seqno());
-                    return h1 ^ (h2 << 1);
+
+                    return h1 ^ (h2 << 3);
                 }
             };
 

xo-interpreter2/src/skrepl/skreplxx.cpp

@@ -9,6 +9,9 @@
 #include <xo/facet/FacetRegistry.hpp>
 #include <replxx.hxx>
 #include <iostream>
+#ifdef __APPLE__
+#include <unistd.h> // for STDIN_FILENO on OSX
+#endif
 
 namespace xo {
     using xo::scm::VirtualSchematikaMachine;
@@ -85,7 +88,7 @@ namespace xo {
 
         AppConfig(const ReplConfig & repl_cfg = ReplConfig(),
                   const ArenaConfig & app_arena_cfg = ArenaConfig().with_name("skreplxx").with_size(16 * 1024),
-                  const VsmConfig & vsm_cfg = VsmConfig()) 
+                  const VsmConfig & vsm_cfg = VsmConfig())
         : repl_config_{repl_cfg}, app_arena_config_{app_arena_cfg}, vsm_config_{vsm_cfg}
         {
             //rdr_config_.reader_debug_flag_ = true;
@@ -239,4 +242,3 @@ main (int argc, char * argv[])
 } /*main*/
 
 /* end skreplxx.cpp */
-

xo-interpreter2/utest/VirtualSchematikaMachine.test.cpp

@@ -73,8 +73,8 @@ namespace xo {
                 };
 
                 aux_mm_.arena_.visit_pools(visitor);
-                FacetRegistry::instance().visit_pools(visitor);
                 TypeRegistry::instance().visit_pools(visitor);
+                FacetRegistry::instance().visit_pools(visitor);
                 vsm_.visit_pools(visitor);
 
                 return true;
@@ -189,6 +189,37 @@ namespace xo {
             log && vsm_fixture.log_memory_layout(&log);
         }
 
+        TEST_CASE("VirtualSchematikaMachine-arith2", "[interpreter2][VSM]")
+        {
+            const auto & testname = Catch::getResultCapture().getCurrentTestName();
+
+            constexpr bool c_debug_flag = true;
+            scope log(XO_DEBUG(c_debug_flag), xtag("test", testname));
+
+            VsmFixture vsm_fixture(testname, c_debug_flag);
+            auto & vsm = vsm_fixture.vsm_;
+
+            bool eof_flag = false;
+
+            vsm.begin_interactive_session();
+            VsmResultExt res = vsm.read_eval_print(span_type::from_cstr("3.14159265 / 0.5;"), eof_flag);
+
+            REQUIRE(res.is_value());
+            REQUIRE(res.value());
+
+            log && log(xtag("res.tseq", res.value()->_typeseq()));
+
+            auto x = obj<AGCObject,DFloat>::from(*res.value());
+
+            REQUIRE(x);
+            REQUIRE(x.data()->value() == 6.2831853);
+
+            REQUIRE(res.remaining_.size() == 1);
+            REQUIRE(*res.remaining_.lo() == '\n');
+
+            log && vsm_fixture.log_memory_layout(&log);
+        }
+
         TEST_CASE("VirtualSchematikaMachine-cmp1", "[interpreter2][VSM]")
         {
             const auto & testname = Catch::getResultCapture().getCurrentTestName();

xo-numeric/CMakeLists.txt

@@ -29,14 +29,32 @@ xo_add_genfacet(
 
 # ----------------------------------------------------------------
 
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-numeric-facetimpl-numeric-float
+    FACET_PKG xo_numeric
+    FACET Numeric
+    REPR Float
+    INPUT idl/INumeric_DFloat.json5
+)
+
+# note: manual target; generated code committed to git
+xo_add_genfacetimpl(
+    TARGET xo-numeric-facetimpl-numeric-integer
+    FACET_PKG xo_numeric
+    FACET Numeric
+    REPR Integer
+    INPUT idl/INumeric_DInteger.json5
+)
+
+# ----------------------------------------------------------------
+
 xo_add_genfacet_all(xo-numeric-genfacet-all)
 
 # ----------------------------------------------------------------
 
-#add_subdirectory(src/numeric)   # NOTE: will need cmake export here
-#add_subdirectory(utest)
+add_subdirectory(src/numeric)
+add_subdirectory(utest)
 
 # ----------------------------------------------------------------
 # cmake export
-
-

xo-numeric/NumericDispatch.hpp

@@ -1,44 +0,0 @@
-/** @file NumericDispatch.hpp
- *
- *  @author Roland Conybeare, Feb 2026
- **/
-
-#pragma once
-
-//#include <xo/facet/FacetRegistry.hpp>  // probably will need this at some point?
-#include <xo/arena/DArenaHashMap.hpp>
-#include <utility>
-
-namespace xo {
-    namespace scm {
-
-        /** type-erased arithmetic dispatch.
-         **/
-        struct NumericOps {
-            obj<ANumeric>
-        };
-
-        class NumericDispatch {
-        public:
-            using KeyType = std::pair<typeseq, typeseq>;
-            using MapType = xo::map::DArenaHashMap<KeyType, MappedType, KeyHash>
-
-            /** combine two typeseq's to get hash value **/
-            struct KeyHash {
-                std::size_t operator()(const key_type & k) const noexcept {
-                    // combine the two seqno values
-                    std::size_t h1 = std::hash<int32_t>{}(k.first.seqno());
-                    std::size_t h2 = std::hash<int32_t>{}(k.second.seqno());
-                    return h1 ^ (h2 << 1);
-                }
-            };
-
-
-        };
-
-    } /*namespace scm*/
-} /*namespace xo*/
-
-/* end NumericDispqatch.hpp */
-
-

xo-numeric/cmake/xo_numericConfig.cmake.in

@@ -7,7 +7,7 @@ include(CMakeFindDependencyMacro)
 #       in CMakeLists.txt
 #
 #find_dependency(xo_gc)
-find_dependency(xo_facet)
+find_dependency(xo_procedure2)
 find_dependency(subsys)
 #find_dependency(indentlog)
 

xo-numeric/idl/INumeric_DFloat.json5

@@ -0,0 +1,18 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/numeric",
+    output_hpp_dir: "include/xo/numeric",
+    output_impl_subdir: "float",
+    includes: [
+//      "<xo/printable2/Printable.hpp>",
+//      "<xo/printable2/detail/IPrintable_Xfer.hpp>"
+    ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Numeric.json5",
+    brief: "provide ANumeric interface for DFloat",
+    using_doxygen: true,
+    repr: "DFloat",
+    doc: [ "implement ANumeric for DFloat" ],
+}

xo-numeric/idl/INumeric_DInteger.json5

@@ -0,0 +1,18 @@
+{
+    mode: "implementation",
+    output_cpp_dir: "src/numeric",
+    output_hpp_dir: "include/xo/numeric",
+    output_impl_subdir: "integer",
+    includes: [
+//      "<xo/printable2/Printable.hpp>",
+//      "<xo/printable2/detail/IPrintable_Xfer.hpp>"
+    ],
+    local_types: [ ],
+    namespace1: "xo",
+    namespace2: "scm",
+    facet_idl: "idl/Numeric.json5",
+    brief: "provide ANumeric interface for DInteger",
+    using_doxygen: true,
+    repr: "DInteger",
+    doc: [ "implement ANumeric for DInteger" ],
+}

xo-numeric/include/xo/numeric/FloatIntegerOps.hpp

@@ -0,0 +1,42 @@
+/** @file FloatIntegerOps.hpp
+ *
+ *  @author Roland Conybeare, Feb 2026
+ **/
+
+#pragma once
+
+#include "Numeric.hpp"
+#include <xo/procedure2/RuntimeContext.hpp>
+#include <xo/object2/Float.hpp>
+#include <xo/object2/Integer.hpp>
+
+
+namespace xo {
+    namespace scm {
+
+        class FloatIntegerOps {
+        public:
+            using AGCObject = xo::mm::AGCObject;
+
+        public:
+            static obj<AGCObject> multiply(obj<ARuntimeContext> rcx,
+                                           DFloat * x, DInteger * y);
+            static obj<AGCObject> divide(obj<ARuntimeContext> rcx,
+                                         DFloat * x, DInteger * y);
+        };
+
+        class IntegerFloatOps {
+        public:
+            using AGCObject = xo::mm::AGCObject;
+
+        public:
+            static obj<AGCObject> multiply(obj<ARuntimeContext> rcx,
+                                           DInteger * x, DFloat * y);
+            static obj<AGCObject> divide(obj<ARuntimeContext> rcx,
+                                         DInteger * x, DFloat * y);
+        };
+
+    }
+}
+
+/* end FloatIntegerOps.hpp */

xo-numeric/include/xo/numeric/FloatOps.hpp

@@ -0,0 +1,30 @@
+/** @file FloatOps.hpp
+ *
+ *  @author Roland Conybeare, Feb 2026
+ **/
+
+#pragma once
+
+#include "Numeric.hpp"
+#include <xo/procedure2/RuntimeContext.hpp>
+#include <xo/object2/Float.hpp>
+
+
+namespace xo {
+    namespace scm {
+
+        class FloatOps {
+        public:
+            using AGCObject = xo::mm::AGCObject;
+
+        public:
+            static obj<AGCObject> multiply(obj<ARuntimeContext> rcx,
+                                           DFloat * x, DFloat * y);
+            static obj<AGCObject> divide(obj<ARuntimeContext> rcx,
+                                         DFloat * x, DFloat * y);
+        };
+
+    }
+}
+
+/* end FloatOps.hpp */

xo-numeric/include/xo/numeric/IntegerOps.hpp

@@ -0,0 +1,31 @@
+/** @file IntegerOps.hpp
+ *
+ *  @author Roland Conybeare, Feb 2026
+ **/
+
+#pragma once
+
+#include "Numeric.hpp"
+#include <xo/procedure2/RuntimeContext.hpp>
+#include <xo/object2/Integer.hpp>
+
+namespace xo {
+    namespace scm {
+
+        class IntegerOps {
+        public:
+            using AGCObject = xo::mm::AGCObject;
+
+        public:
+            static obj<AGCObject> multiply(obj<ARuntimeContext> rcx,
+                                           DInteger * x, DInteger * y);
+
+            static obj<AGCObject> divide(obj<ARuntimeContext> rcx,
+                                         DInteger * x, DInteger * y);
+
+        };
+
+    }
+}
+
+/* end IntegerOps.hpp */

xo-numeric/include/xo/numeric/NumericDispatch.hpp

@@ -5,13 +5,93 @@
 
 #pragma once
 
+#include "NumericOps.hpp"
+#include <xo/procedure2/RuntimeContext.hpp>
+#include <xo/gc/GCObject.hpp>
+#include <xo/arena/DArenaHashMap.hpp>
+#include <xo/reflectutil/typeseq.hpp>
+
 namespace xo {
     namespace scm {
 
+        /** Runtime polymoprhic multimethod dispatch.
+         *  Hash on argument types to get function table
+         **/
         class NumericDispatch {
         public:
+            //using AAllocator = xo::mm::AAllocator;
+            using AGCObject = xo::mm::AGCObject;
+            using MemorySizeVisitor = xo::mm::MemorySizeVisitor;
+            using typeseq = xo::reflect::typeseq;
+            using KeyType = std::pair<typeseq, typeseq>;
+            using MappedType = AnonymizedNumericOps;
 
-            
+            /** hash function for key_type **/
+            struct KeyHash {
+
+                std::size_t operator()(const KeyType & k) const noexcept {
+                    // combine the two seqno values
+                    std::size_t h1 = std::hash<int32_t>{}(k.first.seqno());
+                    std::size_t h2 = std::hash<int32_t>{}(k.second.seqno());
+
+                    return h1 ^ (h2 << 7);
+                }
+
+            };
+
+            using MapType = xo::map::DArenaHashMap<KeyType,
+                                                   MappedType,
+                                                   KeyHash,
+                                                   std::equal_to<void>>;
+
+        public:
+            NumericDispatch(uint32_t hint_max_capacity)
+                : dispatch_{"numeric-dispatch",
+                hint_max_capacity,
+                false /*!debug_flag*/} {}
+
+            /** @p hint_max_capacity only honored the first time instance()
+             *  is called.
+             **/
+            static NumericDispatch & instance(uint32_t hint_max_capacity = 64) {
+                static NumericDispatch s_instance(hint_max_capacity);
+                return s_instance;
+            }
+
+            /** multiply w/ runtime polymorphism (double-dispatch)
+             **/
+            static obj<AGCObject> multiply(obj<ARuntimeContext> rcx,
+                                           obj<AGCObject> x,
+                                           obj<AGCObject> y);
+
+            /** divide w/ runtime polymorphism (double-dispatch)
+             **/
+            static obj<AGCObject> divide(obj<ARuntimeContext> rcx,
+                                         obj<AGCObject> x,
+                                         obj<AGCObject> y);
+
+            /** report memory use for owned arenas to @p visitor **/
+            void visit_pools(const MemorySizeVisitor & visitor);
+
+            /** Use:
+             *  Need to have overload
+             *    multiply(obj<AAllocator>, DRepr1, DRepr2) -> obj<ANumeric>
+             *  available
+             **/
+            template <typename DRepr1, typename DRepr2>
+            void register_impl(typename NumericOps<DRepr1, DRepr2>::BinaryOp_Impl mul_fn,
+                               typename NumericOps<DRepr1, DRepr2>::BinaryOp_Impl div_fn) {
+
+                KeyType key(typeseq::id<DRepr1>().seqno(),
+                            typeseq::id<DRepr2>().seqno());
+
+                // note: copying op table so they're in proximity
+                this->dispatch_[key] = NumericOps<DRepr1, DRepr2>::make(mul_fn, div_fn);
+            }
+
+        private:
+            /** 2d dispatch for arithmetic **/
+            MapType dispatch_;
         };
 
     } /*namespace scm*/

xo-numeric/include/xo/numeric/NumericOps.hpp

@@ -1,44 +1,52 @@
 /** @file NumericOps.hpp
-*
+ *
  *  @author Roland Conybeare, Feb 2026
  **/
 
 #pragma once
 
-#include "Numeric.hpp"
+#include <xo/numeric/Numeric.hpp>
+#include <xo/procedure2/RuntimeContext.hpp>
+#include <xo/gc/GCObject.hpp>
+#include <xo/facet/obj.hpp>
 
 namespace xo {
     namespace scm {
-
-        class INumericOps {
+        class AnonymizedNumericOps {
         public:
-            using BinaryOp1 = obj<ANumeric> (*)(obj<AAllocator> mm, void * x, void * y);
+            using ARuntimeContext = xo::scm::ARuntimeContext;
+            using AGCObject = xo::mm::AGCObject;
+            using BinaryOp = obj<AGCObject> (*)(obj<ARuntimeContext> mm, void * x, void * y);
 
         public:
-            explicit INumericOp9s(BinaryOp1 multiply) : multiply_{multiply} {}
+            /** note: null ctor load-bearing for membership in DArenaHashTable **/
+            AnonymizedNumericOps() = default;
+            /** @p multiply to multiply (x,y); allocate from mm **/
+            explicit AnonymizedNumericOps(BinaryOp multiply,
+                                          BinaryOp divide)
+                : multiply_{multiply}, divide_{divide} {}
 
-            /** multiply (x,y); allocate from mm **/
-            BinaryOp1 multiply_;
+            BinaryOp multiply_ = nullptr;
+            BinaryOp divide_ = nullptr;
         };
 
-        /** Convenience template. To use, provide implementation
-         *  for
-         *    _multiply() ...
-         *  
-         **/
         template <typename DRepr1, typename DRepr2>
-        class NumericOps : public INumericOps {
+        class NumericOps {
         public:
-            using BinaryOp1_Impl = obj<ANumeric> (*)(obj<AAllocator> mm, DRepr1 * x, DRepr2 * y);
+            using ARuntimeContext = xo::scm::ARuntimeContext;
+            using AGCObject = xo::mm::AGCObject;
+            using BinaryOp_Impl = obj<AGCObject> (*)(obj<ARuntimeContext> rcx, DRepr1 * x, DRepr2 * y);
+            using BinaryOp_Anon = AnonymizedNumericOps::BinaryOp;
 
         public:
-            explicit NumericOps(BinaryOp1_Impl multiply)
-                    : INumericOps(reinterpret_cast<INumericOps::BinaryOp1>(multiply))
-            {}
+            static AnonymizedNumericOps make(BinaryOp_Impl multiply,
+                                             BinaryOp_Impl divide) {
+                return AnonymizedNumericOps(reinterpret_cast<BinaryOp_Anon>(multiply),
+                                            reinterpret_cast<BinaryOp_Anon>(divide));
+            }
         };
 
     } /*namespace scm*/
 } /*namespace xo*/
 
 /* end NumericOps.hpp */
-

xo-numeric/include/xo/numeric/NumericPrimitives.hpp

@@ -0,0 +1,23 @@
+/** @file NumericDispatch.hpp
+ *
+ *  @author Roland Conybeare, Feb 2026
+ **/
+
+#pragma once
+
+#include <xo/procedure2/DPrimitive_gco_2_gco_gco.hpp>
+
+namespace xo {
+    namespace scm {
+
+        /** @brief primitives using multidispatch
+         **/
+        class NumericPrimitives {
+        public:
+            /** poly divide **/
+            static DPrimitive_gco_2_gco_gco s_div_gco_gco_pm;
+        };
+    }
+}
+
+/* end NumericDispatch.hpp */

xo-numeric/include/xo/numeric/float/INumeric_DFloat.hpp

@@ -0,0 +1,56 @@
+/** @file INumeric_DFloat.hpp
+ *
+ *  Generated automagically from ingredients:
+ *  1. code generator:
+ *       [xo-facet/codegen/genfacet]
+ *     arguments:
+ *       --input [idl/INumeric_DFloat.json5]
+ *  2. jinja2 template for abstract facet .hpp file:
+ *       [iface_facet_repr.hpp.j2]
+ *  3. idl for facet methods
+ *       [idl/INumeric_DFloat.json5]
+ **/
+
+#pragma once
+
+#include "Numeric.hpp"
+#include "DFloat.hpp"
+
+namespace xo { namespace scm { class INumeric_DFloat; } }
+
+namespace xo {
+    namespace facet {
+        template <>
+        struct FacetImplementation<xo::scm::ANumeric,
+                                   xo::scm::DFloat>
+        {
+            using ImplType = xo::scm::INumeric_Xfer
+              <xo::scm::DFloat,
+               xo::scm::INumeric_DFloat>;
+        };
+    }
+}
+
+namespace xo {
+    namespace scm {
+        /** @class INumeric_DFloat
+         **/
+        class INumeric_DFloat {
+        public:
+            /** @defgroup scm-numeric-dfloat-type-traits **/
+            ///@{
+            using Copaque = xo::scm::ANumeric::Copaque;
+            using Opaque = xo::scm::ANumeric::Opaque;
+            ///@}
+            /** @defgroup scm-numeric-dfloat-methods **/
+            ///@{
+            // const methods
+
+            // non-const methods
+            ///@}
+        };
+
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end */

xo-numeric/include/xo/numeric/init_numeric.hpp

@@ -0,0 +1,21 @@
+/** @file init_numeric.hpp
+ *
+ *  @author Roland Conybeare, Feb 2026
+ **/
+
+#pragma once
+
+#include <xo/subsys/Subsystem.hpp>
+
+namespace xo {
+    /* tag to represent the xo-numeric/ subsystem within ordered initialization */
+    enum S_numeric_tag {};
+
+    template <>
+    struct InitSubsys<S_numeric_tag> {
+        static void init();
+        static InitEvidence require();
+    };
+}
+
+/* end init_numeric.hpp */

xo-numeric/include/xo/numeric/integer/INumeric_DInteger.hpp

@@ -0,0 +1,56 @@
+/** @file INumeric_DInteger.hpp
+ *
+ *  Generated automagically from ingredients:
+ *  1. code generator:
+ *       [xo-facet/codegen/genfacet]
+ *     arguments:
+ *       --input [idl/INumeric_DInteger.json5]
+ *  2. jinja2 template for abstract facet .hpp file:
+ *       [iface_facet_repr.hpp.j2]
+ *  3. idl for facet methods
+ *       [idl/INumeric_DInteger.json5]
+ **/
+
+#pragma once
+
+#include "Numeric.hpp"
+#include "DInteger.hpp"
+
+namespace xo { namespace scm { class INumeric_DInteger; } }
+
+namespace xo {
+    namespace facet {
+        template <>
+        struct FacetImplementation<xo::scm::ANumeric,
+                                   xo::scm::DInteger>
+        {
+            using ImplType = xo::scm::INumeric_Xfer
+              <xo::scm::DInteger,
+               xo::scm::INumeric_DInteger>;
+        };
+    }
+}
+
+namespace xo {
+    namespace scm {
+        /** @class INumeric_DInteger
+         **/
+        class INumeric_DInteger {
+        public:
+            /** @defgroup scm-numeric-dinteger-type-traits **/
+            ///@{
+            using Copaque = xo::scm::ANumeric::Copaque;
+            using Opaque = xo::scm::ANumeric::Opaque;
+            ///@}
+            /** @defgroup scm-numeric-dinteger-methods **/
+            ///@{
+            // const methods
+
+            // non-const methods
+            ///@}
+        };
+
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end */

xo-numeric/include/xo/numeric/numeric_register_facets.hpp

@@ -0,0 +1,16 @@
+/** @file numeric_register_facets.hpp
+ *
+ *  @author Roland Conybeare, Feb 2026
+ **/
+
+#pragma once
+
+namespace xo {
+    namespace scm {
+        /** Setup numeric facet dispatch **/
+        bool numeric_register_facets();
+
+    }
+}
+
+/* end numeric_register_facets.hpp */

xo-numeric/src/numeric/CMakeLists.txt

@@ -0,0 +1,25 @@
+# numeric/CMakeLists.txt
+
+set(SELF_LIB xo_numeric)
+set(SELF_SRCS
+    init_numeric.cpp
+    numeric_register_facets.cpp
+    NumericPrimitives.cpp
+    NumericDispatch.cpp
+    INumeric_Any.cpp
+    FloatIntegerOps.cpp
+    FloatOps.cpp
+    IntegerOps.cpp
+)
+
+xo_add_shared_library4(${SELF_LIB} ${PROJECT_NAME}Targets ${PROJECT_VERSION} 1 ${SELF_SRCS})
+xo_dependency(${SELF_LIB} xo_procedure2)
+xo_dependency(${SELF_LIB} subsys)
+
+xo_export_cmake_config(${PROJECT_NAME} ${PROJECT_VERSION} ${PROJECT_NAME}Targets)
+
+# ----------------------------------------------------------------
+# docs targets depend on other library/utest/exec targets above,
+# --> must come after them.
+#
+#add_subdirectory(docs)

xo-numeric/src/numeric/FloatIntegerOps.cpp

@@ -0,0 +1,48 @@
+/** @file FloatIntegerOps.cp
+ *
+ *  @author Roland Conybeare, Feb 2206
+ **/
+
+#include "FloatIntegerOps.hpp"
+#include "float/INumeric_DFloat.hpp"
+
+namespace xo {
+    using xo::mm::AGCObject;
+
+    namespace scm {
+
+        // ----- Float op Integer -----
+
+        obj<AGCObject>
+        FloatIntegerOps::multiply(obj<ARuntimeContext> rcx,
+                                  DFloat * x, DInteger * y)
+        {
+            return DFloat::box<AGCObject>(rcx.allocator(), x->value() * y->value());
+        }
+
+        obj<AGCObject>
+        FloatIntegerOps::divide(obj<ARuntimeContext> rcx,
+                                DFloat * x, DInteger * y)
+        {
+            return DFloat::box<AGCObject>(rcx.allocator(), x->value() / y->value());
+        }
+
+        // ----- Integer op Float -----
+
+        obj<AGCObject>
+        IntegerFloatOps::multiply(obj<ARuntimeContext> rcx,
+                                  DInteger * x, DFloat * y)
+        {
+            return DFloat::box<AGCObject>(rcx.allocator(), x->value() * y->value());
+        }
+
+        obj<AGCObject>
+        IntegerFloatOps::divide(obj<ARuntimeContext> rcx,
+                                DInteger * x, DFloat * y)
+        {
+            return DFloat::box<AGCObject>(rcx.allocator(), x->value() / y->value());
+        }
+    }
+}
+
+/* end FloatIntegerOps.cpp */

xo-numeric/src/numeric/FloatOps.cpp

@@ -0,0 +1,31 @@
+/** @file FloatOps.cp
+ *
+ *  @author Roland Conybeare, Feb 2206
+ **/
+
+#include "FloatOps.hpp"
+#include "float/INumeric_DFloat.hpp"
+
+namespace xo {
+    using xo::mm::AGCObject;
+
+    namespace scm {
+
+        obj<AGCObject>
+        FloatOps::multiply(obj<ARuntimeContext> rcx,
+                           DFloat * x, DFloat * y)
+        {
+            return DFloat::box<AGCObject>(rcx.allocator(), x->value() * y->value());
+        }
+
+        obj<AGCObject>
+        FloatOps::divide(obj<ARuntimeContext> rcx,
+                           DFloat * x, DFloat * y)
+        {
+            return DFloat::box<AGCObject>(rcx.allocator(), x->value() / y->value());
+        }
+
+    }
+}
+
+/* end FloatOps.cpp */

xo-numeric/src/numeric/INumeric_DFloat.cpp

@@ -0,0 +1,22 @@
+/** @file INumeric_DFloat.cpp
+ *
+ *  Generated automagically from ingredients:
+ *  1. code generator:
+ *       [xo-facet/codegen/genfacet]
+ *     arguments:
+ *       --input [idl/INumeric_DFloat.json5]
+ *  2. jinja2 template for abstract facet .hpp file:
+ *       [iface_facet_any.hpp.j2]
+ *  3. idl for facet methods
+ *       [idl/INumeric_DFloat.json5]
+**/
+
+#include "float/INumeric_DFloat.hpp"
+
+namespace xo {
+    namespace scm {
+
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end INumeric_DFloat.cpp */

xo-numeric/src/numeric/INumeric_DInteger.cpp

@@ -0,0 +1,22 @@
+/** @file INumeric_DInteger.cpp
+ *
+ *  Generated automagically from ingredients:
+ *  1. code generator:
+ *       [xo-facet/codegen/genfacet]
+ *     arguments:
+ *       --input [idl/INumeric_DInteger.json5]
+ *  2. jinja2 template for abstract facet .hpp file:
+ *       [iface_facet_any.hpp.j2]
+ *  3. idl for facet methods
+ *       [idl/INumeric_DInteger.json5]
+**/
+
+#include "integer/INumeric_DInteger.hpp"
+
+namespace xo {
+    namespace scm {
+
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end INumeric_DInteger.cpp */

xo-numeric/src/numeric/IntegerOps.cpp

@@ -0,0 +1,31 @@
+/** @file IntegerOps.cpp
+ *
+ *  @author Roland Conybeare, Feb 2026
+ **/
+
+#include "IntegerOps.hpp"
+#include "integer/INumeric_DInteger.hpp"
+
+namespace xo {
+    using xo::mm::AGCObject;
+
+    namespace scm {
+
+        obj<AGCObject>
+        IntegerOps::multiply(obj<ARuntimeContext> rcx,
+                             DInteger * x, DInteger * y)
+        {
+            return DInteger::box<AGCObject>(rcx.allocator(), x->value() * y->value());
+        }
+
+        obj<AGCObject>
+        IntegerOps::divide(obj<ARuntimeContext> rcx,
+                           DInteger * x, DInteger * y)
+        {
+            return DInteger::box<AGCObject>(rcx.allocator(), x->value() / y->value());
+        }
+
+    }
+}
+
+/* end IntegerOps.cpp */

xo-numeric/src/numeric/NumericDispatch.cpp

@@ -0,0 +1,59 @@
+/** @file NumericDispatch.cpp
+ *
+ *  @author Roland Conybeare, Feb 2026
+ **/
+
+#include "NumericDispatch.hpp"
+#include <xo/indentlog/scope.hpp>
+
+namespace xo {
+    using xo::mm::AGCObject;
+
+    namespace scm {
+
+        void
+        NumericDispatch::visit_pools(const MemorySizeVisitor & visitor)
+        {
+            dispatch_.visit_pools(visitor);
+        }
+
+        obj<AGCObject>
+        NumericDispatch::multiply(obj<ARuntimeContext> rcx,
+                                  obj<AGCObject> x,
+                                  obj<AGCObject> y)
+        {
+            KeyType key(x._typeseq(), y._typeseq());
+
+            auto target_fn
+                = NumericDispatch::instance().dispatch_[key].multiply_;
+
+            return (*target_fn)(rcx, x.data(), y.data());
+        }
+
+        obj<AGCObject>
+        NumericDispatch::divide(obj<ARuntimeContext> rcx,
+                                obj<AGCObject> x,
+                                obj<AGCObject> y)
+        {
+            scope log(XO_DEBUG(true));
+
+            KeyType key(x._typeseq(), y._typeseq());
+
+            log && log(xtag("x.tseq", x._typeseq().seqno()),
+                       xtag("y.tseq", y._typeseq().seqno()));
+
+            auto target_fn
+                = NumericDispatch::instance().dispatch_[key].divide_;
+
+            log && log(xtag("target_fn", target_fn));
+
+            assert(target_fn);
+
+            return (*target_fn)(rcx, x.data(), y.data());
+        }
+
+
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end NumericDispatch.cpp **/

xo-numeric/src/numeric/NumericPrimitives.cpp

@@ -0,0 +1,22 @@
+/** @file NumericPrimitives.cpp
+ *
+ *  @author Roland Conybeare, Feb 2026
+ **/
+
+#include "NumericPrimitives.hpp"
+#include "NumericDispatch.hpp"
+
+namespace xo {
+    using xo::mm::AGCObject;
+
+    namespace scm {
+
+        DPrimitive_gco_2_gco_gco
+        NumericPrimitives::s_div_gco_gco_pm("_div",
+                                            &NumericDispatch::divide);
+
+
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end NumericDispatch.cpp */

xo-numeric/src/numeric/init_numeric.cpp

@@ -0,0 +1,36 @@
+/** @file init_numeric.cpp
+ *
+ *  @author Roland Conybeare, Feb 2026
+ **/
+
+#include "init_numeric.hpp"
+#include <xo/procedure2/init_procedure2.hpp>
+#include "Subsystem.hpp"
+#include "numeric_register_facets.hpp"
+
+namespace xo {
+    using xo::scm::numeric_register_facets;
+
+    void
+    InitSubsys<S_numeric_tag>::init()
+    {
+        numeric_register_facets();
+    }
+
+    InitEvidence
+    InitSubsys<S_numeric_tag>::require()
+    {
+        InitEvidence retval;
+
+        /* direct subsystem deps for xo-numeric/ */
+        retval ^= InitSubsys<S_procedure2_tag>::require();
+
+        /* xo-numeric/'s own initialization code */
+        retval ^= Subsystem::provide<S_numeric_tag>("numeric", &init);
+
+        return retval;
+    }
+
+} /*namespace xo*/
+
+/* end init_numeric.cpp */

xo-numeric/src/numeric/numeric_register_facets.cpp

@@ -0,0 +1,61 @@
+/** @file numeric_register_facets.cpp
+ *
+ *  @author Roland Conybeare, Feb 2026
+ **/
+
+#include "numeric_register_facets.hpp"
+#include "NumericDispatch.hpp"
+#include "Numeric.hpp"
+
+#include "FloatIntegerOps.hpp"
+#include "FloatOps.hpp"
+#include "float/INumeric_DFloat.hpp"
+
+#include "IntegerOps.hpp"
+#include "integer/INumeric_DInteger.hpp"
+
+#include <xo/object2/DFloat.hpp>
+#include <xo/object2/Integer.hpp>
+
+#include <xo/facet/FacetRegistry.hpp>
+#include <xo/reflectutil/typeseq.hpp>
+#include <xo/indentlog/scope.hpp>
+
+namespace xo {
+    using xo::facet::FacetRegistry;
+    using xo::reflect::typeseq;
+
+    namespace scm {
+
+        bool
+        numeric_register_facets()
+        {
+            scope log(XO_DEBUG(true));
+
+            FacetRegistry::register_impl<ANumeric, DInteger>();
+
+            NumericDispatch::instance().register_impl<DFloat, DFloat>
+                (&FloatOps::multiply,
+                 &FloatOps::divide);
+
+            NumericDispatch::instance().register_impl<DFloat, DInteger>
+                (&FloatIntegerOps::multiply,
+                 &FloatIntegerOps::divide);
+
+            NumericDispatch::instance().register_impl<DInteger, DFloat>
+                (&IntegerFloatOps::multiply,
+                 &IntegerFloatOps::divide);
+
+            NumericDispatch::instance().register_impl<DInteger, DInteger>
+                (&IntegerOps::multiply,
+                 &IntegerOps::divide);
+
+            log && log(xtag("ANumeric.tseq", typeseq::id<ANumeric>()));
+
+            return true;
+        }
+
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end numeric_register_facets.cpp */

xo-numeric/utest/CMakeLists.txt

@@ -0,0 +1,12 @@
+# built unittest xo-numeric/utest
+
+set(UTEST_EXE utest.numeric)
+set(UTEST_SRCS
+    numeric_utest_main.cpp
+    Numeric.test.cpp
+)
+
+xo_add_utest_executable(${UTEST_EXE} ${UTEST_SRCS})
+xo_self_dependency(${UTEST_EXE} xo_numeric)
+#xo_dependency(${UTEST_EXE} randomgen)
+xo_external_target_dependency(${UTEST_EXE} Catch2 Catch2::Catch2)

xo-numeric/utest/Numeric.test.cpp

@@ -0,0 +1,76 @@
+/** @file Numeric.test.cpp
+ *
+ *  @author Roland Conybeare, Feb 2026
+ **/
+
+#include "init_numeric.hpp"
+#include "NumericDispatch.hpp"
+#include <xo/facet/FacetRegistry.hpp>
+#include <xo/facet/TypeRegistry.hpp>
+#include <catch2/catch.hpp>
+
+namespace xo {
+    using xo::scm::NumericDispatch;
+    //using xo::mm::AAllocator;
+    using xo::mm::DArena;
+    using xo::mm::ArenaConfig;;
+    using xo::mm::MemorySizeInfo;
+    using xo::facet::FacetRegistry;
+    using xo::facet::TypeRegistry;
+    //using xo::facet::with_facet;
+    //using xo::facet::obj;
+
+    namespace ut {
+
+        namespace {
+            struct Fixture {
+                explicit Fixture(const std::string & testname,
+                                 std::size_t aux_arena_size = 16 * 1024)
+                    : aux_arena_(
+                        ArenaConfig().with_name(testname).with_size(aux_arena_size))
+                    {}
+
+
+                bool log_memory_layout(scope * p_log) {
+                    auto visitor = [p_log](const MemorySizeInfo & info) {
+                        *p_log && (*p_log)(xtag("resource", info.resource_name_),
+                                           xtag("used", info.used_),
+                                           xtag("alloc", info.allocated_),
+                                           xtag("commit", info.committed_),
+                                           xtag("resv", info.reserved_));
+                    };
+
+                    aux_arena_.visit_pools(visitor);
+                    TypeRegistry::instance().visit_pools(visitor);
+                    FacetRegistry::instance().visit_pools(visitor);
+                    NumericDispatch::instance().visit_pools(visitor);
+
+                    return true;
+                }
+
+                DArena aux_arena_;
+            };
+        } /*namespace*/
+
+        static InitEvidence s_init = (InitSubsys<S_numeric_tag>::require());
+
+        TEST_CASE("Numeric-init" "[numeric]")
+        {
+            const auto & testname = Catch::getResultCapture().getCurrentTestName();
+
+            constexpr bool c_debug_flag = true;
+            scope log(XO_DEBUG(c_debug_flag), xtag("test", testname));
+
+            Fixture fixture(testname);
+            {
+                // real purpose: ensure s_init sutvives static linking
+                REQUIRE(s_init.evidence());
+            }
+
+            log && fixture.log_memory_layout(&log);
+        }
+
+    } /*namespace ut*/
+} /*namespace xo*/
+
+/* end Numeric.test.cpp */

xo-numeric/utest/numeric_utest_main.cpp

@@ -0,0 +1,24 @@
+/* file numeric_utest_main.cpp */
+
+#include <xo/subsys/Subsystem.hpp>
+
+#define CATCH_CONFIG_RUNNER
+#include "catch2/catch.hpp"
+
+int
+main(int argc, char* argv[])
+{
+    using xo::Subsystem;
+
+    // Your custom initialization code here
+    Subsystem::initialize_all();
+
+    // Run Catch2's test session
+    int result = Catch::Session().run(argc, argv);
+
+    // cleanup here, if any
+
+    return result;
+}
+
+/* end numeric_utest_main.cpp */

xo-reader2/cmake/xo_reader2Config.cmake.in

@@ -6,6 +6,7 @@ include(CMakeFindDependencyMacro)
 #       must coordinate with xo_dependency() calls
 #       in CMakeLists.txt
 #
+find_dependency(xo_numeric)
 find_dependency(xo_procedure2)
 find_dependency(xo_gc)
 find_dependency(xo_tokenizer2)

xo-reader2/src/reader2/CMakeLists.txt

@@ -73,6 +73,7 @@ set(SELF_SRCS
 
 xo_add_shared_library4(${SELF_LIB} ${PROJECT_NAME}Targets ${PROJECT_VERSION} 1 ${SELF_SRCS})
 # note: deps here must also appear in cmake/xo_expression2Config.cmake.in
+xo_dependency(${SELF_LIB} xo_numeric)
 xo_dependency(${SELF_LIB} xo_procedure2)
 xo_dependency(${SELF_LIB} xo_gc)
 xo_dependency(${SELF_LIB} xo_tokenizer2)

xo-reader2/src/reader2/DProgressSsm.cpp

@@ -12,6 +12,8 @@
 #include "ApplySsm.hpp"
 #include "ParenSsm.hpp"
 
+#include <xo/numeric/NumericPrimitives.hpp>
+
 #include <xo/expression2/DApplyExpr.hpp>
 #include <xo/expression2/detail/IExpression_DApplyExpr.hpp>
 
@@ -118,15 +120,15 @@ namespace xo {
                 switch (tktype) {
                 case tokentype::tk_assign:
                     return optype::op_assign;
-                case tokentype::tk_plus:
+                case tokentype::tk_plus:        // [+]
                     return optype::op_add;
-                case tokentype::tk_minus:
+                case tokentype::tk_minus:       // [-]
                     return optype::op_subtract;
-                case tokentype::tk_star:
+                case tokentype::tk_star:        // [*]
                     return optype::op_multiply;
-                case tokentype::tk_slash:
+                case tokentype::tk_slash:       // [/]
                     return optype::op_divide;
-                case tokentype::tk_cmpeq:
+                case tokentype::tk_cmpeq:       // [==]
                     return optype::op_equal;
                 case tokentype::tk_cmpne:
                     return optype::op_not_equal;
@@ -297,12 +299,12 @@ namespace xo {
                 break;
 
             case tokentype::tk_star:
+            case tokentype::tk_slash:
             case tokentype::tk_minus:
             case tokentype::tk_cmpeq:
                 this->on_operator_token(tk, p_psm);
                 return;
 
-            case tokentype::tk_slash:
             case tokentype::tk_cmpne:
             case tokentype::tk_type:
             case tokentype::tk_lambda:
@@ -1283,9 +1285,40 @@ namespace xo {
 
                 break;
             case optype::op_divide:
-                // TODO: implement binary operator expression assembly
-                assert(false);
+                {
+                    auto pm_obj  = (with_facet<AGCObject>::mkobj
+                                    (&NumericPrimitives::s_div_gco_gco_pm));
+                    auto fn_expr = (DConstant::make
+                                    (p_psm->expr_alloc(), pm_obj));
+
+                    /* note:
+                     * 1. don't assume we know lhs_ / rhs_ value types yet.
+                     *    perhaps have expression like
+                     *      f(..) * g(..)
+                     *    where f is the function that contains current ssm.
+                     *
+                     * 2. consequence: we need representation for
+                     *    polymorphic multiply on unknown numeric arguments.
+                     *
+                     * 3. TypeRef::dwim(..) is a placeholder.
+                     *    Plan to later provide abstract interpreter
+                     *    (ie compiler pass :) to drive type inference/unification
+                     *
+                     * 4. Alternatively could supply type-annotation syntax
+                     *    so human can assist inference; context here is we want
+                     *    to automate the boring stuff
+                     */
+
+                    TypeRef tref = TypeRef::dwim
+                                       (TypeRef::prefix_type::from_chars("_div_gco"),
+                                        nullptr);
+
+                    return DApplyExpr::make2(p_psm->expr_alloc(),
+                                             tref, fn_expr, lhs_, rhs_);
+                }
+
                 break;
+
             case optype::op_subtract: /* editor bait: op_minus */
                 {
                     auto pm_obj = (with_facet<AGCObject>::mkobj

xo-reader2/src/reader2/init_reader2.cpp

@@ -8,6 +8,7 @@
 #include "reader2_register_types.hpp"
 
 #include <xo/expression2/init_expression2.hpp>
+#include <xo/numeric/init_numeric.hpp>
 #include <xo/gc/CollectorTypeRegistry.hpp>
 
 namespace xo {
@@ -30,6 +31,7 @@ namespace xo {
 
         /* direct subsystem deps for xo-reader2/ */
         retval ^= InitSubsys<S_expression2_tag>::require();
+        retval ^= InitSubsys<S_numeric_tag>::require();
 
         /* xo-reader2/'s own initialization code */
         retval ^= Subsystem::provide<S_reader2_tag>("reader2", &init);

xo-reader2/utest/SchematikaParser.test.cpp

@@ -578,6 +578,67 @@ namespace xo {
             log && fixture.log_memory_layout(&log);
         }
 
+        TEST_CASE("SchematikaParser-interactive-arith2", "[reader2][SchematikaParser]")
+        {
+            const auto & testname = Catch::getResultCapture().getCurrentTestName();
+
+            constexpr bool c_debug_flag = false;
+            scope log(XO_DEBUG(c_debug_flag), xtag("test", testname));
+
+            ParserFixture fixture(testname, c_debug_flag);
+            auto & parser = *(fixture.parser_);
+
+            parser.begin_interactive_session();
+
+            /** Walkthrough parsing input equivalent to:
+             *
+             *    3.14159265 / 10.0 ;
+             *
+             **/
+
+            std::vector<Token> tk_v{
+                Token::f64_token("3.14159265"),
+                Token::slash_token(),
+                Token::f64_token("10.0"),
+                Token::semicolon_token(),
+            };
+
+            INFO(testname);
+
+            utest_tokenizer_loop(&parser, tk_v, c_debug_flag);
+
+            const auto & result = parser.result();
+            {
+                auto expr = obj<AExpression,DApplyExpr>::from(result.result_expr());
+                REQUIRE(expr);
+
+                REQUIRE(expr->n_args() == 2);
+
+                auto fn = obj<AExpression,DConstant>::from(expr->fn());
+                REQUIRE(fn);
+
+                auto pm = obj<AGCObject,DPrimitive_gco_2_gco_gco>::from(fn->value());
+                REQUIRE(pm);
+                REQUIRE(pm->name() == "_div");
+
+                auto lhs = obj<AExpression,DConstant>::from(expr->arg(0));
+                REQUIRE(lhs);
+
+                auto lhs_f64 = obj<AGCObject,DFloat>::from(lhs->value());
+                REQUIRE(lhs_f64);
+                REQUIRE(lhs_f64->value() == 3.14159265);
+
+                auto rhs = obj<AExpression,DConstant>::from(expr->arg(1));
+                REQUIRE(rhs);
+
+                auto rhs_f64 = obj<AGCObject,DFloat>::from(rhs->value());
+                REQUIRE(rhs_f64);
+                REQUIRE(rhs_f64->value() == 10.0);
+            }
+
+            log && fixture.log_memory_layout(&log);
+        }
+
         TEST_CASE("SchematikaParser-interactive-cmp", "[reader2][SchematikaParser]")
         {
             const auto & testname = Catch::getResultCapture().getCurrentTestName();