Add globals and OP_DEF operation

6 files changed, 87 insertions, 5 deletions

diff --git a/src/bytecode/compiler.h b/src/bytecode/compiler.h
index ec51942..8f3fa81 100755
--- a/src/bytecode/compiler.h
+++ b/src/bytecode/compiler.h
@@ -177,6 +177,52 @@ compile_list_simple_op(Chunk *chunk, Visitor *vs, Token start, Ops op) {
 }
 
 void
+compile_define_op(Chunk *chunk, Visitor *vs, Token start) {
+    Token name = peek_token(vs);
+    if (name.type != TOKEN_SYMBOL) {
+        error_push((Error){
+            .type = ERR_TYPE_COMPILER,
+            .value = ERR_WRONG_ARG_TYPE,
+            .line = start.line,
+            .col = start.column,
+        });
+        return;
+    }
+    parse_tree(chunk, vs);
+    Token expr = peek_token(vs);
+    if (name.type == TOKEN_EOF || expr.type == TOKEN_EOF) {
+        error_push((Error){
+            .type = ERR_TYPE_COMPILER,
+            .value = ERR_UNBALANCED_PAREN,
+            .line = start.line,
+            .col = start.column,
+        });
+        return;
+    }
+    if (name.type == TOKEN_RPAREN || expr.type == TOKEN_RPAREN) {
+        error_push((Error){
+            .type = ERR_TYPE_COMPILER,
+            .value = ERR_NOT_ENOUGH_ARGS,
+            .line = start.line,
+            .col = start.column,
+        });
+        return;
+    }
+    parse_tree(chunk, vs);
+    if (peek_token(vs).type != TOKEN_RPAREN) {
+        error_push((Error){
+            .type = ERR_TYPE_COMPILER,
+            .value = ERR_TOO_MANY_ARGS,
+            .line = start.line,
+            .col = start.column,
+        });
+        return;
+    }
+    next_token(vs);
+    add_code(chunk, OP_DEF, start.line, start.column);
+}
+
+void
 parse_list(Chunk *chunk, Visitor *vs, Token start) {
     if (!has_next_token(vs)) {
         error_push((Error){
@@ -205,6 +251,7 @@ parse_list(Chunk *chunk, Visitor *vs, Token start) {
         case TOKEN_PRINT: { compile_list_unary_op(chunk, vs, start, OP_PRINT); } break;
         case TOKEN_DISPLAY: { compile_list_unary_op(chunk, vs, start, OP_DISPLAY); } break;
         case TOKEN_NEWLINE: { compile_list_simple_op(chunk, vs, start, OP_NEWLINE); } break;
+        case TOKEN_DEF: { compile_define_op(chunk, vs, start); } break;
         default: {
             error_push((Error){
                 .type = ERR_TYPE_COMPILER,
@@ -219,6 +266,9 @@ parse_list(Chunk *chunk, Visitor *vs, Token start) {
 void
 parse_tree(Chunk *chunk, Visitor *vs) {
     Token tok = next_token(vs);
+    if (errors_n != 0) {
+        return;
+    }
     switch (tok.type) {
         case TOKEN_FIXNUM: {
             parse_fixnum(chunk, tok);
diff --git a/src/bytecode/debug.h b/src/bytecode/debug.h
index 52cf431..52b237a 100755
--- a/src/bytecode/debug.h
+++ b/src/bytecode/debug.h
@@ -9,6 +9,7 @@ size_t disassemble_instruction(Chunk *chunk, size_t offset);
 static const char* ops_str[] = {
     // Load/store ops.
     [OP_CONSTANT] = "OP_CONSTANT",
+    [OP_DEF] = "OP_DEF",
     // Arithmetic ops.
     [OP_SUM] = "OP_SUM",
     [OP_SUB] = "OP_SUB",
diff --git a/src/bytecode/main.c b/src/bytecode/main.c
index f7d1f74..85882b3 100755
--- a/src/bytecode/main.c
+++ b/src/bytecode/main.c
@@ -8,13 +8,15 @@
 // Config.
 //
 
-// #define DEBUG_TRACE_EXECUTION
+#ifdef DEBUG
+#define DEBUG_TRACE_EXECUTION
+#endif
 
 #include "vm.h"
+#include "errors.c"
 #include "compiler.h"
 #include "ops.h"
 #include "debug.h"
-#include "errors.c"
 #include "lexer.c"
 #include "read_line.c"
 #include "string_view.c"
@@ -48,12 +50,14 @@ process_source(const StringView *source) {
         return;
     }
 
+#ifdef DEBUG
+    disassemble_chunk(chunk, "current chunk");
+#endif
+
     // Interpret chunk.
     vm_interpret(&vm, chunk);
-    if (errors_n != 0) {
-        disassemble_chunk(vm.chunk, "current chunk");
-    }
 
+    // Free resources.
     chunk_free(chunk);
     array_free(tokens);
 }
diff --git a/src/bytecode/objects.h b/src/bytecode/objects.h
index fc5e069..9744071 100755
--- a/src/bytecode/objects.h
+++ b/src/bytecode/objects.h
@@ -159,4 +159,20 @@ object_equal(Object a, Object b) {
     return true;
 }
 
+Object
+object_copy(Object src) {
+    switch (src.type) {
+        case OBJ_TYPE_SYMBOL:
+        case OBJ_TYPE_STRING: {
+            Object copy = src;
+            copy.text = NULL;
+            array_init(copy.text, array_size(src.text));
+            array_insert(copy.text, src.text, array_size(src.text));
+            return copy;
+        } break;
+        default: { break; } break;
+    }
+    return src;
+}
+
 #endif // BDL_OBJECTS_H
diff --git a/src/bytecode/ops.h b/src/bytecode/ops.h
index 348df84..63442ac 100755
--- a/src/bytecode/ops.h
+++ b/src/bytecode/ops.h
@@ -4,6 +4,7 @@
 typedef enum Ops {
     // Load/store ops.
     OP_CONSTANT,
+    OP_DEF,
     // Arithmetic ops.
     OP_SUM,
     OP_SUB,
diff --git a/src/bytecode/vm.h b/src/bytecode/vm.h
index f1886ec..23370bb 100755
--- a/src/bytecode/vm.h
+++ b/src/bytecode/vm.h
@@ -6,6 +6,7 @@
 #include "chunk.h"
 #include "ops.h"
 #include "debug.h"
+#include "hashtable.h"
 
 #define VM_STACK_CAP 1024
 
@@ -16,6 +17,8 @@ typedef struct VM {
     u8 *pc;
     // Stack.
     Object *stack;
+    // Global variables.
+    HashTable *globals;
 } VM;
 
 void vm_init(VM *vm);
@@ -27,11 +30,13 @@ void
 vm_init(VM *vm) {
     *vm = (VM){0};
     array_init(vm->stack, VM_STACK_CAP);
+    vm->globals = ht_init();
 }
 
 void
 vm_free(VM *vm) {
     array_free(vm->stack);
+    ht_free(vm->globals);
 }
 
 void
@@ -142,6 +147,11 @@ vm_interpret(VM *vm, Chunk *chunk) {
                 Object obj = vm->chunk->constants[constant];
                 array_push(vm->stack, obj);
             } break;
+            case OP_DEF: {
+                Object value = array_pop(vm->stack);
+                Object name = array_pop(vm->stack);
+                ht_insert(vm->globals, name, value);
+            } break;
             case OP_SUM: { FIXNUM_ARITHMETIC_OP(+); } break;
             case OP_SUB: { FIXNUM_ARITHMETIC_OP(-); } break;
             case OP_MUL: { FIXNUM_ARITHMETIC_OP(*); } break;