From f0cd7a3cab56a6f8d7b4520aaa168a271a94d6d4 Mon Sep 17 00:00:00 2001
From: Bad Diode <bd@badd10de.dev>
Date: Wed, 27 Oct 2021 10:43:30 +0200
Subject: Add initial implementation of locals

---
 src/bytecode/compiler.h | 48 +++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 41 insertions(+), 7 deletions(-)

(limited to 'src/bytecode/compiler.h')

diff --git a/src/bytecode/compiler.h b/src/bytecode/compiler.h
index 6a17beb..7497ea7 100755
--- a/src/bytecode/compiler.h
+++ b/src/bytecode/compiler.h
@@ -34,8 +34,8 @@ has_next_token(const Compiler *compiler) {
 ssize_t
 find_local_index(Chunk *chunk, Token tok) {
     // NOTE: This is dumb and potentially slow.
-    for (size_t i = 0; i < array_size(chunk->params); i++) {
-        if (sv_equal(&tok.value, &chunk->params[i])) {
+    for (size_t i = 0; i < array_size(chunk->locals); i++) {
+        if (sv_equal(&tok.value, &chunk->locals[i])) {
             return i;
         }
     }
@@ -203,9 +203,11 @@ compile_list_simple_op(Chunk *chunk, Compiler *compiler, Token start, Ops op) {
     });
 }
 
+#define STR_ARRAY(ARR) (StringView){(ARR), array_size(ARR)}
+
 void
 compile_declare_op(Chunk *chunk, Compiler *compiler, Token start, Ops op) {
-    Token name = peek_token(compiler);
+    Token name = next_token(compiler);
     if (name.type != TOKEN_SYMBOL) {
         error_push((Error){
             .type = ERR_TYPE_COMPILER,
@@ -215,9 +217,29 @@ compile_declare_op(Chunk *chunk, Compiler *compiler, Token start, Ops op) {
         });
         return;
     }
-    Object obj = make_symbol(name.value);
-    emit_constant(chunk, name, obj);
-    next_token(compiler);
+    // TODO: If we are inside a function and we are using OP_DEF, we just
+    // declare the local variable directly in the stack. No need for symbols!
+    // TODO: If we are inside a function and we are using OP_SET, check if the
+    // local variable has been defined before, if not try to read from the
+    // globals for setting.
+    if (sv_equal(&STRING(""), &STR_ARRAY(chunk->name))) {
+        Object obj = make_symbol(name.value);
+        emit_constant(chunk, name, obj);
+    } else {
+        // TODO: only do this if we are defining! not setting.
+        // Check if we already have the local
+        ssize_t idx = find_local_index(chunk, name);
+        if (idx < 0) {
+            array_push(chunk->locals, name.value);
+            idx = array_size(chunk->locals) - 1;
+        }
+        if (op == OP_DEF) {
+            op = OP_DEF_LOCAL;
+        } else if (op == OP_SET) {
+            op = OP_SET_LOCAL;
+        }
+        emit_constant(chunk, name, FIXNUM_VAL(idx));
+    }
 
     Token tok = peek_token(compiler);
     if (name.type == TOKEN_EOF || tok.type == TOKEN_EOF) {
@@ -282,7 +304,19 @@ compile_lambda(Chunk *chunk, Compiler *compiler, Token start, StringView name) {
                 });
                 return;
             }
+            // Check if parameters name already exists.
+            ssize_t idx = find_local_index(fun.chunk, tok);
+            if (idx >= 0) {
+                error_push((Error){
+                    .type = ERR_TYPE_COMPILER,
+                    .value = ERR_AMBIGUOUS_PARAMS,
+                    .line = tok.line,
+                    .col = tok.column,
+                });
+                return;
+            }
             array_push(fun.chunk->params, tok.value);
+            array_push(fun.chunk->locals, tok.value);
         }
     } else if (tok.type != TOKEN_NIL) {
         error_push((Error){
@@ -549,7 +583,7 @@ parse_tree(Chunk *chunk, Compiler *compiler) {
 Chunk *
 compile(Token *tokens) {
     Chunk *chunk = NULL;
-    chunk = NEW_CHUNK("main");
+    chunk = NEW_CHUNK("");
     Compiler compiler = (Compiler){
         .tokens = tokens,
         .current = 0,
-- 
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