feat: synchronize after finding an error to find all errors at one compile not fixing bugs after each compile

Author: aymaneelmaini

src/chunk.h

@@ -10,6 +10,7 @@ typedef enum
     OP_NIL,
     OP_TRUE,
     OP_FALSE,
+    OP_POP,
     OP_EQUAL,
     OP_GREATER,
     OP_LESS,

src/compiler.c

@@ -352,16 +352,55 @@ static void expression()
 
 // ---------------------- statements --------------------------
 
+static void expression_statement()
+{
+    expression();
+    consume(TOKEN_SEMICOLON, "Expect ';' after expression.");
+    emit_byte(OP_POP);
+}
+
 static void print_statement()
 {
     expression();
-    consume(TOKEN_SEMICOLON, "Expect ';' at the end of print statement");
+    consume(TOKEN_SEMICOLON, "Expect ';' at the end of print statement.");
     emit_byte(OP_PRINT);
 }
 
+static void synchronize()
+{
+    parser.panic_mode = false;
+
+    while (parser.current.type != TOKEN_EOF)
+    {
+        if (parser.previous.type == TOKEN_SEMICOLON)
+            return;
+
+        switch (parser.current.type)
+        {
+        case TOKEN_CLASS:
+        case TOKEN_FUN:
+        case TOKEN_VAR:
+        case TOKEN_FOR:
+        case TOKEN_IF:
+        case TOKEN_WHILE:
+        case TOKEN_PRINT:
+        case TOKEN_RETURN:
+            return;
+
+        default:
+            // do nothings
+            ;
+        }
+        advance();
+    }
+}
+
 static void declaration()
 {
     statement();
+
+    if (parser.panic_mode)
+        synchronize();
 }
 
 static void statement()
@@ -370,6 +409,10 @@ static void statement()
     {
         print_statement();
     }
+    else
+    {
+        expression_statement();
+    }
 }
 
 static inline void init_parser()

src/debug.c

@@ -42,6 +42,8 @@ int disassemble_instruction(Chunk* chunk, int offset)
         return simple_instruction("OP_FALSE", offset);
     case OP_TRUE:
         return simple_instruction("OP_TRUE", offset);
+    case OP_POP:
+        return simple_instruction("OP_POP", offset);
     case OP_EQUAL:
         return simple_instruction("OP_EQUAL", offset);
     case OP_GREATER:

src/vm.c

@@ -132,6 +132,9 @@ static InterpretResult run()
         case OP_FALSE:
             push(BOOL_VAL(false));
             break;
+        case OP_POP:
+            pop();
+            break;
         case OP_EQUAL:
         {
             Value v2 = pop();