From d3f14cf53cf857b90184900a726e3ee0875dea80 Mon Sep 17 00:00:00 2001
From: Bruce Hill <bruce@bruce-hill.com>
Date: Sun, 14 Jul 2024 14:13:23 -0400
Subject: Support nested lambda closures

---
 compile.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

(limited to 'compile.c')

diff --git a/compile.c b/compile.c
index a49ab29c..938c1c0c 100644
--- a/compile.c
+++ b/compile.c
@@ -62,13 +62,15 @@ static table_t *get_closed_vars(env_t *env, ast_t *lambda_ast)
 {
     auto lambda = Match(lambda_ast, Lambda);
     env_t *body_scope = fresh_scope(env);
+    body_scope->code = new(compilation_unit_t); // Don't put any code in the headers or anything
     for (arg_ast_t *arg = lambda->args; arg; arg = arg->next) {
         type_t *arg_type = get_arg_ast_type(env, arg);
         set_binding(body_scope, arg->name, new(binding_t, .type=arg_type, .code=CORD_cat("$", arg->name)));
     }
 
     fn_ctx_t fn_ctx = (fn_ctx_t){
-        .closure_scope=body_scope->locals->fallback,
+        .parent=env->fn_ctx,
+        .closure_scope=env->locals,
         .closed_vars=new(table_t),
     };
     body_scope->fn_ctx = &fn_ctx;
@@ -596,6 +598,7 @@ CORD compile_statement(env_t *env, ast_t *ast)
         }
 
         fn_ctx_t fn_ctx = (fn_ctx_t){
+            .parent=NULL,
             .return_type=ret_t,
             .closure_scope=NULL,
             .closed_vars=NULL,
@@ -717,6 +720,9 @@ CORD compile_statement(env_t *env, ast_t *ast)
             code = CORD_all(
                 code, compile_declaration(entry->b->type, defer_name), " = ", entry->b->code, ";\n");
             set_binding(defer_env, entry->name, new(binding_t, .type=entry->b->type, .code=defer_name));
+
+            if (env->fn_ctx->closed_vars)
+                Table$str_set(env->fn_ctx->closed_vars, entry->name, entry->b);
         }
         env->deferred = new(deferral_t, .defer_env=defer_env, .block=body, .next=env->deferred);
         return code;
@@ -1738,7 +1744,8 @@ CORD compile(env_t *env, ast_t *ast)
         }
 
         fn_ctx_t fn_ctx = (fn_ctx_t){
-            .closure_scope=body_scope->locals->fallback,
+            .parent=env->fn_ctx,
+            .closure_scope=env->locals,
             .closed_vars=new(table_t),
         };
         body_scope->fn_ctx = &fn_ctx;
@@ -1749,6 +1756,14 @@ CORD compile(env_t *env, ast_t *ast)
             ret_t = Match(ret_t, ReturnType)->ret;
         fn_ctx.return_type = ret_t;
 
+        if (env->fn_ctx->closed_vars) {
+            for (int64_t i = 1; i <= Table$length(*env->fn_ctx->closed_vars); i++) {
+                struct { const char *name; binding_t *b; } *entry = Table$entry(*env->fn_ctx->closed_vars, i);
+                set_binding(body_scope, entry->name, new(binding_t, .type=entry->b->type, .code=CORD_cat("userdata->", entry->name)));
+                Table$str_set(fn_ctx.closed_vars, entry->name, entry->b);
+            }
+        }
+
         CORD code = CORD_all("static ", compile_type(ret_t), " ", name, "(");
         for (arg_ast_t *arg = lambda->args; arg; arg = arg->next) {
             type_t *arg_type = get_arg_ast_type(env, arg);
@@ -1769,7 +1784,7 @@ CORD compile(env_t *env, ast_t *ast)
                 struct { const char *name; binding_t *b; } *entry = Table$entry(*closed_vars, i);
                 if (entry->b->type->tag == ModuleType)
                     continue;
-                userdata = CORD_all(userdata, ", ", entry->b->code);
+                userdata = CORD_all(userdata, ", ", get_binding(env, entry->name)->code);
             }
             userdata = CORD_all(userdata, ")");
             code = CORD_all(code, name, "$userdata_t *userdata)");
-- 
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