From 190477add86e311bbcd661f5af5324467637277a Mon Sep 17 00:00:00 2001
From: Kayne Ruse <kayneruse@gmail.com>
Date: Tue, 26 May 2026 18:01:49 +1000
Subject: [PATCH] Fixed negative variables handled incorrectly

---
 repl/bytecode_inspector.c |  4 ++++
 source/toy_ast.h          |  5 +++--
 source/toy_compiler.c     | 11 +++++++++++
 source/toy_opcodes.h      |  1 +
 source/toy_parser.c       |  2 +-
 source/toy_vm.c           | 20 ++++++++++++++++++++
 6 files changed, 40 insertions(+), 3 deletions(-)

diff --git a/repl/bytecode_inspector.c b/repl/bytecode_inspector.c
index 99121b6..deb3611 100644
--- a/repl/bytecode_inspector.c
+++ b/repl/bytecode_inspector.c
@@ -233,6 +233,10 @@ int inspect_instruction(unsigned char* bytecode, unsigned int pc, unsigned int j
 			printf(MARKER "MODULO %s\n", MARKER_VALUE(pc, unsigned char), bytecode[pc + 1] == TOY_OPCODE_ASSIGN ? "and ASSIGN" : "");
 			return 4;
 
+		case TOY_OPCODE_INVERT:
+			printf(MARKER "INVERT\n", MARKER_VALUE(pc, unsigned char));
+			return 4;
+
 		case TOY_OPCODE_COMPARE_EQUAL:
 			printf(MARKER "COMPARE %s\n", MARKER_VALUE(pc, unsigned char), bytecode[pc + 1] != TOY_OPCODE_NEGATE ? "==" : "!=");
 			return 4;
diff --git a/source/toy_ast.h b/source/toy_ast.h
index 1754dcd..0e79887 100644
--- a/source/toy_ast.h
+++ b/source/toy_ast.h
@@ -86,9 +86,10 @@ typedef enum Toy_AstFlag {
 	TOY_AST_FLAG_PREFIX_DECREMENT = 42,
 	TOY_AST_FLAG_POSTFIX_INCREMENT = 43,
 	TOY_AST_FLAG_POSTFIX_DECREMENT = 44,
+	TOY_AST_FLAG_INVERT = 45,
 
-	TOY_AST_FLAG_INVOKATION = 45,
-	TOY_AST_FLAG_ATTRIBUTE = 46,
+	TOY_AST_FLAG_INVOKATION = 46,
+	TOY_AST_FLAG_ATTRIBUTE = 47,
 
 	// TOY_AST_FLAG_TERNARY,
 } Toy_AstFlag;
diff --git a/source/toy_compiler.c b/source/toy_compiler.c
index ab939b2..a73669f 100644
--- a/source/toy_compiler.c
+++ b/source/toy_compiler.c
@@ -377,6 +377,17 @@ static unsigned int writeInstructionUnary(Toy_Bytecode** mb, Toy_AstUnary ast) {
 		result = 1;
 	}
 
+	else if (ast.flag == TOY_AST_FLAG_INVERT) {
+		result = writeBytecodeFromAst(mb, ast.child);
+
+		EMIT_BYTE(mb, code, TOY_OPCODE_INVERT);
+
+		//4-byte alignment
+		EMIT_BYTE(mb, code, 0);
+		EMIT_BYTE(mb, code, 0);
+		EMIT_BYTE(mb, code, 0);
+	}
+
 	else {
 		fprintf(stderr, TOY_CC_ERROR "ERROR: Invalid AST unary flag found\n" TOY_CC_RESET);
 		exit(-1);
diff --git a/source/toy_opcodes.h b/source/toy_opcodes.h
index 0154365..cd7b111 100644
--- a/source/toy_opcodes.h
+++ b/source/toy_opcodes.h
@@ -22,6 +22,7 @@ typedef enum Toy_OpcodeType {
 	TOY_OPCODE_MULTIPLY,
 	TOY_OPCODE_DIVIDE,
 	TOY_OPCODE_MODULO,
+	TOY_OPCODE_INVERT, //negative numbers
 
 	//comparison instructions
 	TOY_OPCODE_COMPARE_EQUAL,
diff --git a/source/toy_parser.c b/source/toy_parser.c
index 75894fa..20d7450 100644
--- a/source/toy_parser.c
+++ b/source/toy_parser.c
@@ -417,7 +417,7 @@ static Toy_AstFlag unary(Toy_Bucket** bucketHandle, Toy_Parser* parser, Toy_Ast*
 		}
 		else {
 			//actually emit the negation node
-			Toy_private_emitAstUnary(bucketHandle, rootHandle, TOY_AST_FLAG_NEGATE);
+			Toy_private_emitAstUnary(bucketHandle, rootHandle, TOY_AST_FLAG_INVERT);
 		}
 	}
 
diff --git a/source/toy_vm.c b/source/toy_vm.c
index 010c0a1..10d906b 100644
--- a/source/toy_vm.c
+++ b/source/toy_vm.c
@@ -554,6 +554,25 @@ static void processIterate(Toy_VM* vm) {
 }
 
 static void processArithmetic(Toy_VM* vm, Toy_OpcodeType opcode) {
+	//BUGFIX: handle negative variables
+	if (opcode == TOY_OPCODE_INVERT) {
+		Toy_Value value = Toy_popStack(&vm->stack);
+		if (TOY_VALUE_IS_INTEGER(value)) {
+			int intermediate = TOY_VALUE_AS_INTEGER(value);
+			Toy_pushStack(&vm->stack, TOY_VALUE_FROM_INTEGER(-intermediate));
+		}
+		else if (TOY_VALUE_IS_FLOAT(value)) {
+			float intermediate = TOY_VALUE_AS_FLOAT(value);
+			Toy_pushStack(&vm->stack, TOY_VALUE_FROM_FLOAT(-intermediate));
+		}
+		else {
+			Toy_error("Can't negate a non-number");
+			Toy_freeValue(value);
+			Toy_pushStack(&vm->stack, TOY_VALUE_FROM_NULL());
+		}
+		return;
+	}
+
 	Toy_Value right = Toy_popStack(&vm->stack);
 	Toy_Value left = Toy_popStack(&vm->stack);
 
@@ -1096,6 +1115,7 @@ static unsigned int process(Toy_VM* vm) {
 			case TOY_OPCODE_MULTIPLY:
 			case TOY_OPCODE_DIVIDE:
 			case TOY_OPCODE_MODULO:
+			case TOY_OPCODE_INVERT:
 				processArithmetic(vm, opcode);
 				break;