Type casting is working:

docs/TODO.txt

@@ -1,7 +1,10 @@
 DONE: rework type system
 DONE: var decl with a type, but no value
+DONE: type casting
 
-TODO: type casting
+TODO: string concat with the + operator
+TODO: empty string as falsy?
+TODO: remove optimization option
 TODO: increment & decrement operators
 TODO: a = b = c = 1;
 TODO: are compounds shallow or deep copies?

scripts/casting.toy

@@ -0,0 +1,30 @@
+//boolean origin
+var b: bool = true;
+
+print (int)b;
+print (float)b;
+print (string)b;
+
+
+//integer origin
+var i: int = 42;
+
+print (bool)i;
+print (float)i;
+print (string)i;
+
+
+//float origin
+var f: float = 3.14;
+
+print (bool)f;
+print (int)f;
+print (string)f;
+
+
+//string origin
+var s: string = "78.9";
+
+print (bool)s;
+print (int)s;
+print (float)s;

scripts/small.toy

@@ -1,6 +0,0 @@
-
-var arr : [int] = [1, 2, 3, 42];
-var dict : [string, int] = ["hello": 1, "world":2];
-
-print arr;
-print dict;

source/compiler.c

@@ -140,7 +140,7 @@ static int writeLiteralTypeToCache(LiteralArray* literalCache, Literal literal)
 
 	//push the store to the cache, tweaking the type
 	Literal lit = TO_ARRAY_LITERAL(store);
-	lit.type = LITERAL_TYPE; //NOTE: tweaking the type usually isn't a good idea
+	lit.type = LITERAL_TYPE_INTERMEDIATE; //NOTE: tweaking the type usually isn't a good idea
 	return pushLiteralArray(literalCache, lit);
 }
 
@@ -463,8 +463,20 @@ unsigned char* collateCompiler(Compiler* compiler, int* size) {
 			break;
 
 			case LITERAL_TYPE: {
+				//push a raw type
 				emitByte(&collation, &capacity, &count, LITERAL_TYPE);
 
+				Literal typeLiteral = compiler->literalCache.literals[i];
+
+				//what type this literal represents
+				emitByte(&collation, &capacity, &count, AS_TYPE(typeLiteral).typeOf);
+				emitByte(&collation, &capacity, &count, AS_TYPE(typeLiteral).constant); //if it's constant
+			}
+			break;
+
+			case LITERAL_TYPE_INTERMEDIATE: {
+				emitByte(&collation, &capacity, &count, LITERAL_TYPE_INTERMEDIATE);
+
 				LiteralArray* ptr = AS_ARRAY(compiler->literalCache.literals[i]); //used an array for storage above
 
 				//the base literal

source/interpreter.c

@@ -361,6 +361,80 @@ static bool execVarAssign(Interpreter* interpreter) {
 	return true;
 }
 
+static bool execValCast(Interpreter* interpreter) {
+	Literal value = popLiteralArray(&interpreter->stack);
+	Literal type = popLiteralArray(&interpreter->stack);
+
+	parseIdentifierToValue(interpreter, &value);
+
+	Literal result = TO_NULL_LITERAL;
+
+	//cast the rhs to the type represented by lhs
+	switch(AS_TYPE(type).typeOf) {
+		case LITERAL_BOOLEAN:
+			result = TO_BOOLEAN_LITERAL(IS_TRUTHY(value));
+		break;
+
+		case LITERAL_INTEGER:
+			if (IS_BOOLEAN(value)) {
+				result = TO_INTEGER_LITERAL(AS_BOOLEAN(value) ? 1 : 0);
+			}
+
+			if (IS_FLOAT(value)) {
+				result = TO_INTEGER_LITERAL(AS_FLOAT(value));
+			}
+
+			if (IS_STRING(value)) {
+				int val = 0;
+				sscanf(AS_STRING(value), "%d", &val);
+				result = TO_INTEGER_LITERAL(val);
+			}
+		break;
+
+		case LITERAL_FLOAT:
+			if (IS_BOOLEAN(value)) {
+				result = TO_FLOAT_LITERAL(AS_BOOLEAN(value) ? 1 : 0);
+			}
+
+			if (IS_INTEGER(value)) {
+				result = TO_FLOAT_LITERAL(AS_INTEGER(value));
+			}
+
+			if (IS_STRING(value)) {
+				float val = 0;
+				sscanf(AS_STRING(value), "%f", &val);
+				result = TO_FLOAT_LITERAL(val);
+			}
+		break;
+
+		case LITERAL_STRING:
+			if (IS_BOOLEAN(value)) {
+				result = TO_STRING_LITERAL(AS_BOOLEAN(value) ? "true" : "false");
+			}
+
+			if (IS_INTEGER(value)) {
+				char buffer[128];
+				snprintf(buffer, 128, "%d", AS_INTEGER(value));
+				result = TO_STRING_LITERAL(buffer);
+			}
+
+			if (IS_FLOAT(value)) {
+				char buffer[128];
+				snprintf(buffer, 128, "%g", AS_FLOAT(value));
+				result = TO_STRING_LITERAL(buffer);
+			}
+		break;
+
+		default:
+			printf("Unknown cast type found %d, terminating\n", AS_TYPE(type).typeOf);
+			return false;
+	}
+
+	//leave the new value on the stack
+	pushLiteralArray(&interpreter->stack, result);
+	return true;
+}
+
 //the heart of toy
 static void execInterpreter(Interpreter* interpreter) {
 	unsigned char opcode = readByte(interpreter->bytecode, &interpreter->count);
@@ -433,6 +507,12 @@ static void execInterpreter(Interpreter* interpreter) {
 				}
 			break;
 
+			case OP_TYPE_CAST:
+				if (!execValCast(interpreter)) {
+					return;
+				}
+			break;
+
 			default:
 				printf("Unknown opcode found %d, terminating\n", opcode);
 				printLiteralArray(&interpreter->stack, "\n");
@@ -602,6 +682,24 @@ void runInterpreter(Interpreter* interpreter, unsigned char* bytecode, int lengt
 			break;
 
 			case LITERAL_TYPE: {
+				//what the literal is
+				LiteralType literalType = (LiteralType)readByte(interpreter->bytecode, &interpreter->count);
+				unsigned char constant = readByte(interpreter->bytecode, &interpreter->count);
+
+				Literal typeLiteral = TO_TYPE_LITERAL(literalType, constant);
+
+				//save the type
+				pushLiteralArray(&interpreter->literalCache, typeLiteral);
+
+				if (command.verbose) {
+					printf("(type ");
+					printLiteral(typeLiteral);
+					printf(")\n");
+				}
+			}
+			break;
+
+			case LITERAL_TYPE_INTERMEDIATE: {
 				//what the literal represents
 				LiteralType literalType = (LiteralType)readByte(interpreter->bytecode, &interpreter->count);
 				unsigned char constant = readByte(interpreter->bytecode, &interpreter->count);

source/literal.c

@@ -322,7 +322,25 @@ void freeLiteral(Literal literal) {
 }
 
 bool _isTruthy(Literal x) {
-	return (IS_NULL(x) || (IS_BOOLEAN(x) && AS_BOOLEAN(x)) || (IS_INTEGER(x) && AS_INTEGER(x) != 0) || (IS_FLOAT(x) && AS_FLOAT(x) != 0));
+	if (IS_NULL(x)) {
+		return false;
+	}
+
+	if (IS_BOOLEAN(x)) {
+		return AS_BOOLEAN(x);
+	}
+
+	if (IS_INTEGER(x)) {
+		return AS_INTEGER(x) != 0;
+	}
+
+	if (IS_FLOAT(x)) {
+		return AS_FLOAT(x) != 0;
+	}
+
+	//TODO: empty string as falsy?
+
+	return true;
 }
 
 Literal _toStringLiteral(char* str) {

source/literal.h

@@ -17,6 +17,7 @@ typedef enum {
 	//these are meta-level types
 	LITERAL_IDENTIFIER,
 	LITERAL_TYPE,
+	LITERAL_TYPE_INTERMEDIATE, //used to process types in the compiler only
 	LITERAL_ANY, //used by the type system only
 } LiteralType;
 

source/opcodes.h

@@ -33,6 +33,8 @@ typedef enum Opcode {
 
 	OP_VAR_ASSIGN,		//assign to a literal
 
+	OP_TYPE_CAST,		//temporarily change a type of an atomic value
+
 	//meta
 	OP_SECTION_END,
 	//TODO: add more

source/parser.c

@@ -266,12 +266,6 @@ static Opcode grouping(Parser* parser, Node** nodeHandle) {
 			parsePrecedence(parser, &tmpNode, PREC_TERNARY);
 			consume(parser, TOKEN_PAREN_RIGHT, "Expected ')' at end of grouping");
 
-			//if it's just a literal, don't need a grouping
-			if (command.optimize >= 1 && tmpNode->type == NODE_LITERAL) {
-				(*nodeHandle) = tmpNode;
-				return OP_EOF;
-			}
-
 			//process the result without optimisations
 			emitNodeGrouping(nodeHandle);
 			nodeHandle = &((*nodeHandle)->unary.child); //re-align after append
@@ -424,13 +418,72 @@ static Opcode identifier(Parser* parser, Node** nodeHandle) {
 	return OP_EOF;
 }
 
+static Opcode castingPrefix(Parser* parser, Node** nodeHandle) {
+	switch(parser->previous.type) {
+		case TOKEN_BOOLEAN:
+			emitNodeLiteral(nodeHandle, TO_TYPE_LITERAL(LITERAL_BOOLEAN, false));
+		break;
+
+		case TOKEN_INTEGER:
+			emitNodeLiteral(nodeHandle, TO_TYPE_LITERAL(LITERAL_INTEGER, false));
+		break;
+
+		case TOKEN_FLOAT:
+			emitNodeLiteral(nodeHandle, TO_TYPE_LITERAL(LITERAL_FLOAT, false));
+		break;
+
+		case TOKEN_STRING:
+			emitNodeLiteral(nodeHandle, TO_TYPE_LITERAL(LITERAL_STRING, false));
+		break;
+
+		default:
+			error(parser, parser->previous, "Unexpected token passed to casting precedence rule");
+			return OP_EOF;
+	}
+
+	return OP_EOF;
+}
+
+static Opcode castingInfix(Parser* parser, Node** nodeHandle) {
+	advance(parser);
+
+	switch(parser->previous.type) {
+		case TOKEN_IDENTIFIER:
+			identifier(parser, nodeHandle);
+		break;
+
+		case TOKEN_LITERAL_TRUE:
+		case TOKEN_LITERAL_FALSE:
+			atomic(parser, nodeHandle);
+		break;
+
+		case TOKEN_LITERAL_INTEGER:
+			atomic(parser, nodeHandle);
+		break;
+
+		case TOKEN_LITERAL_FLOAT:
+			atomic(parser, nodeHandle);
+		break;
+
+		case TOKEN_LITERAL_STRING:
+			atomic(parser, nodeHandle);
+		break;
+
+		default:
+			error(parser, parser->previous, "Unexpected token passed to casting infix precedence rule");
+			return OP_EOF;
+	}
+
+	return OP_TYPE_CAST;
+}
+
 ParseRule parseRules[] = { //must match the token types
 	//types
 	{atomic, NULL, PREC_PRIMARY},// TOKEN_NULL,
-	{NULL, NULL, PREC_NONE},// TOKEN_BOOLEAN,
-	{NULL, NULL, PREC_NONE},// TOKEN_INTEGER,
-	{NULL, NULL, PREC_NONE},// TOKEN_FLOAT,
-	{NULL, NULL, PREC_NONE},// TOKEN_STRING,
+	{castingPrefix, NULL, PREC_CALL},// TOKEN_BOOLEAN,
+	{castingPrefix, NULL, PREC_CALL},// TOKEN_INTEGER,
+	{castingPrefix, NULL, PREC_CALL},// TOKEN_FLOAT,
+	{castingPrefix, NULL, PREC_CALL},// TOKEN_STRING,
 	{NULL, NULL, PREC_NONE},// TOKEN_ARRAY,
 	{NULL, NULL, PREC_NONE},// TOKEN_DICTIONARY,
 	{NULL, NULL, PREC_NONE},// TOKEN_FUNCTION,
@@ -459,12 +512,12 @@ ParseRule parseRules[] = { //must match the token types
 	{NULL, NULL, PREC_NONE},// TOKEN_WHILE,
 
 	//literal values
-	{identifier, NULL, PREC_PRIMARY},// TOKEN_IDENTIFIER,
-	{atomic, NULL, PREC_PRIMARY},// TOKEN_LITERAL_TRUE,
-	{atomic, NULL, PREC_PRIMARY},// TOKEN_LITERAL_FALSE,
-	{atomic, NULL, PREC_PRIMARY},// TOKEN_LITERAL_INTEGER,
-	{atomic, NULL, PREC_PRIMARY},// TOKEN_LITERAL_FLOAT,
-	{string, NULL, PREC_PRIMARY},// TOKEN_LITERAL_STRING,
+	{identifier, castingInfix, PREC_PRIMARY},// TOKEN_IDENTIFIER,
+	{atomic, castingInfix, PREC_PRIMARY},// TOKEN_LITERAL_TRUE,
+	{atomic, castingInfix, PREC_PRIMARY},// TOKEN_LITERAL_FALSE,
+	{atomic, castingInfix, PREC_PRIMARY},// TOKEN_LITERAL_INTEGER,
+	{atomic, castingInfix, PREC_PRIMARY},// TOKEN_LITERAL_FLOAT,
+	{string, castingInfix, PREC_PRIMARY},// TOKEN_LITERAL_STRING,
 
 	//math operators
 	{NULL, binary, PREC_TERM},// TOKEN_PLUS,