From 86e332f2efeb404ac7cc6f52a6b98c609f220170 Mon Sep 17 00:00:00 2001
From: Ryan Fleury <ryan.j.fleury@gmail.com>
Date: Tue, 6 Feb 2024 11:55:51 -0800
Subject: [PATCH] allow compound macro expressions in eval system; poison used
 macro names, before descending

---
 src/eval/eval_compiler.c | 14 ++++++++------
 src/eval/eval_core.c     | 36 +++++++++++++++++++++++++++++++++++-
 src/eval/eval_core.h     |  3 +++
 3 files changed, 46 insertions(+), 7 deletions(-)

diff --git a/src/eval/eval_compiler.c b/src/eval/eval_compiler.c
index e3ffdd35..e303f29d 100644
--- a/src/eval/eval_compiler.c
+++ b/src/eval/eval_compiler.c
@@ -706,11 +706,7 @@ eval_push_leaf_ident_exprs_from_expr__in_place(Arena *arena, EVAL_String2ExprMap
     {
       EVAL_Expr *exprl = expr->children[0];
       EVAL_Expr *exprr = expr->children[1];
-      if(exprl->kind != EVAL_ExprKind_LeafIdent)
-      {
-        eval_errorf(arena, eout, EVAL_ErrorKind_MalformedInput, expr->location, "Left side of assignment must be an identifier.");
-      }
-      else
+      if(exprl->kind == EVAL_ExprKind_LeafIdent)
       {
         eval_string2expr_map_insert(arena, map, exprl->name, exprr);
       }
@@ -1540,6 +1536,10 @@ eval_irtree_and_type_from_expr(Arena *arena, TG_Graph *graph, RADDBG_Parsed *rdb
     
     case EVAL_ExprKind_Define:
     {
+      if(expr->children[0]->kind != EVAL_ExprKind_LeafIdent)
+      {
+        eval_errorf(arena, eout, EVAL_ErrorKind_MalformedInput, expr->location, "Left side of assignment must be an identifier.");
+      }
       result = eval_irtree_and_type_from_expr(arena, graph, rdbg, leaf_ident_expr_map, expr->children[1], eout);
     }break;
     case EVAL_ExprKind_LeafIdent:
@@ -1552,7 +1552,9 @@ eval_irtree_and_type_from_expr(Arena *arena, TG_Graph *graph, RADDBG_Parsed *rdb
       }
       else
       {
-        result = eval_irtree_and_type_from_expr(arena, graph, rdbg, &eval_string2expr_map_nil, leaf_ident_expr, eout);
+        eval_string2expr_map_inc_poison(leaf_ident_expr_map, name);
+        result = eval_irtree_and_type_from_expr(arena, graph, rdbg, leaf_ident_expr_map, leaf_ident_expr, eout);
+        eval_string2expr_map_dec_poison(leaf_ident_expr_map, name);
       }
     }break;
   }
diff --git a/src/eval/eval_core.c b/src/eval/eval_core.c
index 33ef9357..6c26e6e3 100644
--- a/src/eval/eval_core.c
+++ b/src/eval/eval_core.c
@@ -153,6 +153,40 @@ eval_string2expr_map_insert(Arena *arena, EVAL_String2ExprMap *map, String8 stri
   existing_node->expr = expr;
 }
 
+internal void
+eval_string2expr_map_inc_poison(EVAL_String2ExprMap *map, String8 string)
+{
+  U64 hash = eval_hash_from_string(string);
+  U64 slot_idx = hash%map->slots_count;
+  for(EVAL_String2ExprMapNode *node = map->slots[slot_idx].first;
+      node != 0;
+      node = node->hash_next)
+  {
+    if(str8_match(node->string, string, 0))
+    {
+      node->poison_count += 1;
+      break;
+    }
+  }
+}
+
+internal void
+eval_string2expr_map_dec_poison(EVAL_String2ExprMap *map, String8 string)
+{
+  U64 hash = eval_hash_from_string(string);
+  U64 slot_idx = hash%map->slots_count;
+  for(EVAL_String2ExprMapNode *node = map->slots[slot_idx].first;
+      node != 0;
+      node = node->hash_next)
+  {
+    if(str8_match(node->string, string, 0) && node->poison_count > 0)
+    {
+      node->poison_count -= 1;
+      break;
+    }
+  }
+}
+
 internal EVAL_Expr *
 eval_expr_from_string(EVAL_String2ExprMap *map, String8 string)
 {
@@ -164,7 +198,7 @@ eval_expr_from_string(EVAL_String2ExprMap *map, String8 string)
     EVAL_String2ExprMapNode *existing_node = 0;
     for(EVAL_String2ExprMapNode *node = map->slots[slot_idx].first; node != 0; node = node->hash_next)
     {
-      if(str8_match(node->string, string, 0))
+      if(str8_match(node->string, string, 0) && node->poison_count == 0)
       {
         existing_node = node;
         break;
diff --git a/src/eval/eval_core.h b/src/eval/eval_core.h
index 6213ead1..7a1d47cf 100644
--- a/src/eval/eval_core.h
+++ b/src/eval/eval_core.h
@@ -167,6 +167,7 @@ struct EVAL_String2ExprMapNode
   EVAL_String2ExprMapNode *hash_next;
   String8 string;
   EVAL_Expr *expr;
+  U64 poison_count;
 };
 
 typedef struct EVAL_String2ExprMapSlot EVAL_String2ExprMapSlot;
@@ -212,6 +213,8 @@ internal U64 eval_num_from_string(EVAL_String2NumMap *map, String8 string);
 //- rjf: string -> expr
 internal EVAL_String2ExprMap eval_string2expr_map_make(Arena *arena, U64 slot_count);
 internal void eval_string2expr_map_insert(Arena *arena, EVAL_String2NumMap *map, String8 string, EVAL_Expr *expr);
+internal void eval_string2expr_map_inc_poison(EVAL_String2ExprMap *map, String8 string);
+internal void eval_string2expr_map_dec_poison(EVAL_String2ExprMap *map, String8 string);
 internal EVAL_Expr *eval_expr_from_string(EVAL_String2ExprMap *map, String8 string);
 
 #endif // EVAL_CORE_H