Added indexing to strings, tests still needed

source/toy_ast.c

@@ -84,6 +84,17 @@ void Toy_private_emitAstGroup(Toy_Bucket** bucketHandle, Toy_Ast** astHandle) {
 	(*astHandle) = tmp;
 }
 
+void Toy_private_emitAstCompound(Toy_Bucket** bucketHandle, Toy_Ast** astHandle, Toy_AstFlag flag, Toy_Ast* right) {
+	Toy_Ast* tmp = (Toy_Ast*)Toy_partitionBucket(bucketHandle, sizeof(Toy_Ast));
+
+	tmp->type = TOY_AST_COMPOUND;
+	tmp->compound.flag = flag;
+	tmp->compound.left = *astHandle; //left-recursive
+	tmp->compound.right = right;
+
+	(*astHandle) = tmp;
+}
+
 void Toy_private_emitAstPrint(Toy_Bucket** bucketHandle, Toy_Ast** astHandle) {
 	Toy_Ast* tmp = (Toy_Ast*)Toy_partitionBucket(bucketHandle, sizeof(Toy_Ast));
 

source/toy_ast.h

@@ -15,6 +15,7 @@ typedef enum Toy_AstType {
 	TOY_AST_BINARY,
 	TOY_AST_COMPARE,
 	TOY_AST_GROUP,
+	TOY_AST_COMPOUND,
 
 	TOY_AST_PRINT,
 
@@ -52,14 +53,17 @@ typedef enum Toy_AstFlag {
 	TOY_AST_FLAG_COMPARE_GREATER = 24,
 	TOY_AST_FLAG_COMPARE_GREATER_EQUAL = 25,
 
-	TOY_AST_FLAG_AND = 30,
+	TOY_AST_FLAG_COMPOUND_COLLECTION = 30,
-	TOY_AST_FLAG_OR = 31,
+	TOY_AST_FLAG_COMPOUND_INDEX = 31,
-	TOY_AST_FLAG_CONCAT = 32,
+
+	TOY_AST_FLAG_AND = 40,
+	TOY_AST_FLAG_OR = 41,
+	TOY_AST_FLAG_CONCAT = 42,
 
 	//unary flags
-	TOY_AST_FLAG_NEGATE = 33,
+	TOY_AST_FLAG_NEGATE = 43,
-	TOY_AST_FLAG_INCREMENT = 34,
+	TOY_AST_FLAG_INCREMENT = 44,
-	TOY_AST_FLAG_DECREMENT = 35,
+	TOY_AST_FLAG_DECREMENT = 45,
 
 	// TOY_AST_FLAG_TERNARY,
 } Toy_AstFlag;
@@ -105,6 +109,13 @@ typedef struct Toy_AstGroup {
 	Toy_Ast* child;
 } Toy_AstGroup;
 
+typedef struct Toy_AstCompound {
+	Toy_AstType type;
+	Toy_AstFlag flag;
+	Toy_Ast* left;
+	Toy_Ast* right;
+} Toy_AstCompound;
+
 typedef struct Toy_AstPrint {
 	Toy_AstType type;
 	Toy_Ast* child;
@@ -148,6 +159,7 @@ union Toy_Ast {                     //32 | 64 BITNESS
 	Toy_AstBinary binary;           //16 | 24
 	Toy_AstCompare compare;         //16 | 24
 	Toy_AstGroup group;             //8  | 16
+	Toy_AstCompound compound;       //16 | 24
 	Toy_AstPrint print;             //8  | 16
 	Toy_AstVarDeclare varDeclare;   //16 | 24
 	Toy_AstVarAssign varAssign;     //16 | 24
@@ -165,6 +177,7 @@ void Toy_private_emitAstUnary(Toy_Bucket** bucketHandle, Toy_Ast** astHandle, To
 void Toy_private_emitAstBinary(Toy_Bucket** bucketHandle, Toy_Ast** astHandle,Toy_AstFlag flag, Toy_Ast* right);
 void Toy_private_emitAstCompare(Toy_Bucket** bucketHandle, Toy_Ast** astHandle,Toy_AstFlag flag, Toy_Ast* right);
 void Toy_private_emitAstGroup(Toy_Bucket** bucketHandle, Toy_Ast** astHandle);
+void Toy_private_emitAstCompound(Toy_Bucket** bucketHandle, Toy_Ast** astHandle,Toy_AstFlag flag, Toy_Ast* right);
 
 void Toy_private_emitAstPrint(Toy_Bucket** bucketHandle, Toy_Ast** astHandle);
 

source/toy_opcodes.h

@@ -39,6 +39,7 @@ typedef enum Toy_OpcodeType {
 	//various action instructions
 	TOY_OPCODE_PRINT,
 	TOY_OPCODE_CONCAT,
+	TOY_OPCODE_INDEX,
 	//TODO: clear the program stack?
 
 	//meta instructions

source/toy_parser.c

@@ -116,6 +116,7 @@ static Toy_AstFlag literal(Toy_Bucket** bucketHandle, Toy_Parser* parser, Toy_As
 static Toy_AstFlag unary(Toy_Bucket** bucketHandle, Toy_Parser* parser, Toy_Ast** rootHandle);
 static Toy_AstFlag binary(Toy_Bucket** bucketHandle, Toy_Parser* parser, Toy_Ast** rootHandle);
 static Toy_AstFlag group(Toy_Bucket** bucketHandle, Toy_Parser* parser, Toy_Ast** rootHandle);
+static Toy_AstFlag compound(Toy_Bucket** bucketHandle, Toy_Parser* parser, Toy_Ast** rootHandle);
 
 //precedence definitions
 static ParsingTuple parsingRulesetTable[] = {
@@ -194,7 +195,7 @@ static ParsingTuple parsingRulesetTable[] = {
 	//structural operators
 	{PREC_NONE,group,NULL},// TOY_TOKEN_OPERATOR_PAREN_LEFT,
 	{PREC_NONE,NULL,NULL},// TOY_TOKEN_OPERATOR_PAREN_RIGHT,
-	{PREC_NONE,NULL,NULL},// TOY_TOKEN_OPERATOR_BRACKET_LEFT,
+	{PREC_CALL,NULL,compound},// TOY_TOKEN_OPERATOR_BRACKET_LEFT,
 	{PREC_NONE,NULL,NULL},// TOY_TOKEN_OPERATOR_BRACKET_RIGHT,
 	{PREC_NONE,NULL,NULL},// TOY_TOKEN_OPERATOR_BRACE_LEFT,
 	{PREC_NONE,NULL,NULL},// TOY_TOKEN_OPERATOR_BRACE_RIGHT,
@@ -207,7 +208,7 @@ static ParsingTuple parsingRulesetTable[] = {
 	{PREC_NONE,NULL,NULL},// TOY_TOKEN_OPERATOR_COLON,
 
 	{PREC_NONE,NULL,NULL},// TOY_TOKEN_OPERATOR_SEMICOLON, // ;
-	{PREC_NONE,NULL,NULL},// TOY_TOKEN_OPERATOR_COMMA, // ,
+	{PREC_CALL,NULL,compound},// TOY_TOKEN_OPERATOR_COMMA, // ,
 
 	{PREC_NONE,NULL,NULL},// TOY_TOKEN_OPERATOR_DOT, // .
 	{PREC_CALL,NULL,binary},// TOY_TOKEN_OPERATOR_CONCAT, // ..
@@ -557,6 +558,26 @@ static Toy_AstFlag group(Toy_Bucket** bucketHandle, Toy_Parser* parser, Toy_Ast*
 	return TOY_AST_FLAG_NONE;
 }
 
+static Toy_AstFlag compound(Toy_Bucket** bucketHandle, Toy_Parser* parser, Toy_Ast** rootHandle) {
+	//infix must advance
+	advance(parser);
+
+	if (parser->previous.type == TOY_TOKEN_OPERATOR_COMMA) {
+		parsePrecedence(bucketHandle, parser, rootHandle, PREC_ASSIGNMENT + 1);
+		return TOY_AST_FLAG_COMPOUND_COLLECTION;
+	}
+	else if (parser->previous.type == TOY_TOKEN_OPERATOR_BRACKET_LEFT) {
+		parsePrecedence(bucketHandle, parser, rootHandle, PREC_ASSIGNMENT + 1);
+		consume(parser, TOY_TOKEN_OPERATOR_BRACKET_RIGHT, "Expected ']' at the end of index expression");
+		return TOY_AST_FLAG_COMPOUND_INDEX;
+	}
+	else {
+		printError(parser, parser->previous, "Unexpected token passed to compound precedence rule");
+		Toy_private_emitAstError(bucketHandle, rootHandle);
+		return TOY_AST_FLAG_NONE;
+	}
+}
+
 static ParsingTuple* getParsingRule(Toy_TokenType type) {
 	return &parsingRulesetTable[type];
 }
@@ -605,6 +626,7 @@ static void parsePrecedence(Toy_Bucket** bucketHandle, Toy_Parser* parser, Toy_A
 			(*rootHandle) = ptr;
 			return;
 		}
+		//eww, gross
 		else if (flag >= 10 && flag <= 19) {
 			Toy_String* name = Toy_createNameStringLength(bucketHandle, prevToken.lexeme, prevToken.length, TOY_VALUE_UNKNOWN, false);
 			Toy_private_emitAstVariableAssignment(bucketHandle, rootHandle, name, flag, ptr);
@@ -612,6 +634,9 @@ static void parsePrecedence(Toy_Bucket** bucketHandle, Toy_Parser* parser, Toy_A
 		else if (flag >= 20 && flag <= 29) {
 			Toy_private_emitAstCompare(bucketHandle, rootHandle, flag, ptr);
 		}
+		else if (flag >= 30 && flag <= 39) {
+			Toy_private_emitAstCompound(bucketHandle, rootHandle, flag, ptr);
+		}
 		else {
 			Toy_private_emitAstBinary(bucketHandle, rootHandle, flag, ptr);
 		}

source/toy_routine.c

@@ -58,7 +58,7 @@ static void emitToJumpTable(Toy_Routine** rt, unsigned int startAddr) {
 	EMIT_INT(rt, jumps, startAddr); //save address at the jump index
 }
 
-static void emitString(Toy_Routine** rt, Toy_String* str) {
+static unsigned int emitString(Toy_Routine** rt, Toy_String* str) {
 	//4-byte alignment
 	unsigned int length = str->length + 1;
 	if (length % 4 != 0) {
@@ -87,11 +87,13 @@ static void emitString(Toy_Routine** rt, Toy_String* str) {
 
 	//mark the jump position
 	emitToJumpTable(rt, startAddr);
+
+	return 1;
 }
 
-static void writeRoutineCode(Toy_Routine** rt, Toy_Ast* ast); //forward declare for recursion
+static unsigned int writeRoutineCode(Toy_Routine** rt, Toy_Ast* ast); //forward declare for recursion
 
-static void writeInstructionValue(Toy_Routine** rt, Toy_AstValue ast) {
+static unsigned int writeInstructionValue(Toy_Routine** rt, Toy_AstValue ast) {
 	EMIT_BYTE(rt, code, TOY_OPCODE_READ);
 	EMIT_BYTE(rt, code, ast.value.type);
 
@@ -128,17 +130,19 @@ static void writeInstructionValue(Toy_Routine** rt, Toy_AstValue ast) {
 		EMIT_BYTE(rt, code, TOY_STRING_LEAF); //normal string
 		EMIT_BYTE(rt, code, 0); //can't store the length
 
-		emitString(rt, TOY_VALUE_AS_STRING(ast.value));
+		return emitString(rt, TOY_VALUE_AS_STRING(ast.value));
 	}
 	else {
 		fprintf(stderr, TOY_CC_ERROR "ERROR: Invalid AST type found: Unknown value type\n" TOY_CC_RESET);
 		exit(-1);
 	}
+
+	return 1;
 }
 
-static void writeInstructionUnary(Toy_Routine** rt, Toy_AstUnary ast) {
+static unsigned int writeInstructionUnary(Toy_Routine** rt, Toy_AstUnary ast) {
 	//working with a stack means the child gets placed first
-	writeRoutineCode(rt, ast.child);
+	unsigned int result = writeRoutineCode(rt, ast.child);
 
 	if (ast.flag == TOY_AST_FLAG_NEGATE) {
 		EMIT_BYTE(rt, code, TOY_OPCODE_NEGATE);
@@ -152,9 +156,11 @@ static void writeInstructionUnary(Toy_Routine** rt, Toy_AstUnary ast) {
 		fprintf(stderr, TOY_CC_ERROR "ERROR: Invalid AST unary flag found\n" TOY_CC_RESET);
 		exit(-1);
 	}
+
+	return result;
 }
 
-static void writeInstructionBinary(Toy_Routine** rt, Toy_AstBinary ast) {
+static unsigned int writeInstructionBinary(Toy_Routine** rt, Toy_AstBinary ast) {
 	//left, then right, then the binary's operation
 	writeRoutineCode(rt, ast.left);
 	writeRoutineCode(rt, ast.right);
@@ -194,9 +200,11 @@ static void writeInstructionBinary(Toy_Routine** rt, Toy_AstBinary ast) {
 	EMIT_BYTE(rt, code,TOY_OPCODE_PASS); //checked in compound assignments
 	EMIT_BYTE(rt, code,0);
 	EMIT_BYTE(rt, code,0);
+
+	return 1; //leaves only 1 value on the stack
 }
 
-static void writeInstructionCompare(Toy_Routine** rt, Toy_AstCompare ast) {
+static unsigned int writeInstructionCompare(Toy_Routine** rt, Toy_AstCompare ast) {
 	//left, then right, then the compare's operation
 	writeRoutineCode(rt, ast.left);
 	writeRoutineCode(rt, ast.right);
@@ -210,7 +218,7 @@ static void writeInstructionCompare(Toy_Routine** rt, Toy_AstCompare ast) {
 		EMIT_BYTE(rt, code,0);
 		EMIT_BYTE(rt, code,0);
 
-		return;
+		return 1;
 	}
 	else if (ast.flag == TOY_AST_FLAG_COMPARE_LESS) {
 		EMIT_BYTE(rt, code,TOY_OPCODE_COMPARE_LESS);
@@ -234,13 +242,45 @@ static void writeInstructionCompare(Toy_Routine** rt, Toy_AstCompare ast) {
 	EMIT_BYTE(rt, code,0);
 	EMIT_BYTE(rt, code,0);
 	EMIT_BYTE(rt, code,0);
+
+	return 1; //leaves only 1 value on the stack
 }
 
-static void writeInstructionGroup(Toy_Routine** rt, Toy_AstGroup ast) {
+static unsigned int writeInstructionGroup(Toy_Routine** rt, Toy_AstGroup ast) {
-	writeRoutineCode(rt, ast.child);
+	//not certain what this leaves
+	return writeRoutineCode(rt, ast.child);
 }
 
-static void writeInstructionPrint(Toy_Routine** rt, Toy_AstPrint ast) {
+static unsigned int writeInstructionCompound(Toy_Routine** rt, Toy_AstCompound ast) {
+	unsigned int result = 0;
+
+	//left, then right
+	result += writeRoutineCode(rt, ast.left);
+	result += writeRoutineCode(rt, ast.right);
+
+	if (ast.flag == TOY_AST_FLAG_COMPOUND_COLLECTION) {
+		//collections are handled above
+		return result;
+	}
+	else if (ast.flag == TOY_AST_FLAG_COMPOUND_INDEX) {
+		//value[index, length]
+		EMIT_BYTE(rt, code, TOY_OPCODE_INDEX);
+		EMIT_BYTE(rt, code, result);
+
+		//4-byte alignment
+		EMIT_BYTE(rt, code,0);
+		EMIT_BYTE(rt, code,0);
+
+		return 1; //leaves only 1 value on the stack
+	}
+	else {
+		fprintf(stderr, TOY_CC_ERROR "ERROR: Invalid AST compound flag found\n" TOY_CC_RESET);
+		exit(-1);
+		return 0;
+	}
+}
+
+static unsigned int writeInstructionPrint(Toy_Routine** rt, Toy_AstPrint ast) {
 	//the thing to print
 	writeRoutineCode(rt, ast.child);
 
@@ -251,9 +291,11 @@ static void writeInstructionPrint(Toy_Routine** rt, Toy_AstPrint ast) {
 	EMIT_BYTE(rt, code,0);
 	EMIT_BYTE(rt, code,0);
 	EMIT_BYTE(rt, code,0);
+
+	return 0;
 }
 
-static void writeInstructionVarDeclare(Toy_Routine** rt, Toy_AstVarDeclare ast) {
+static unsigned int writeInstructionVarDeclare(Toy_Routine** rt, Toy_AstVarDeclare ast) {
 	//initial value
 	writeRoutineCode(rt, ast.expr);
 
@@ -264,9 +306,13 @@ static void writeInstructionVarDeclare(Toy_Routine** rt, Toy_AstVarDeclare ast)
 	EMIT_BYTE(rt, code, Toy_getNameStringConstant(ast.name) ? 1 : 0); //check for constness
 
 	emitString(rt, ast.name);
+
+	return 0;
 }
 
-static void writeInstructionAssign(Toy_Routine** rt, Toy_AstVarAssign ast) {
+static unsigned int writeInstructionAssign(Toy_Routine** rt, Toy_AstVarAssign ast) {
+	unsigned int result = 0;
+
 	//name, duplicate, right, opcode
 	if (ast.flag == TOY_AST_FLAG_ASSIGN) {
 		EMIT_BYTE(rt, code, TOY_OPCODE_READ);
@@ -275,7 +321,7 @@ static void writeInstructionAssign(Toy_Routine** rt, Toy_AstVarAssign ast) {
 		EMIT_BYTE(rt, code, ast.name->length); //store the length (max 255)
 
 		emitString(rt, ast.name);
-		writeRoutineCode(rt, ast.expr);
+		result += writeRoutineCode(rt, ast.expr);
 
 		EMIT_BYTE(rt, code, TOY_OPCODE_ASSIGN);
 		EMIT_BYTE(rt, code, 0);
@@ -293,7 +339,7 @@ static void writeInstructionAssign(Toy_Routine** rt, Toy_AstVarAssign ast) {
 		EMIT_BYTE(rt, code,0);
 		EMIT_BYTE(rt, code,0);
 
-		writeRoutineCode(rt, ast.expr);
+		result += writeRoutineCode(rt, ast.expr);
 
 		EMIT_BYTE(rt, code,TOY_OPCODE_ADD);
 		EMIT_BYTE(rt, code,TOY_OPCODE_ASSIGN); //squeezed
@@ -311,7 +357,7 @@ static void writeInstructionAssign(Toy_Routine** rt, Toy_AstVarAssign ast) {
 		EMIT_BYTE(rt, code,0);
 		EMIT_BYTE(rt, code,0);
 
-		writeRoutineCode(rt, ast.expr);
+		result += writeRoutineCode(rt, ast.expr);
 
 		EMIT_BYTE(rt, code,TOY_OPCODE_SUBTRACT);
 		EMIT_BYTE(rt, code,TOY_OPCODE_ASSIGN); //squeezed
@@ -329,7 +375,7 @@ static void writeInstructionAssign(Toy_Routine** rt, Toy_AstVarAssign ast) {
 		EMIT_BYTE(rt, code,0);
 		EMIT_BYTE(rt, code,0);
 
-		writeRoutineCode(rt, ast.expr);
+		result += writeRoutineCode(rt, ast.expr);
 
 		EMIT_BYTE(rt, code,TOY_OPCODE_MULTIPLY);
 		EMIT_BYTE(rt, code,TOY_OPCODE_ASSIGN); //squeezed
@@ -347,7 +393,7 @@ static void writeInstructionAssign(Toy_Routine** rt, Toy_AstVarAssign ast) {
 		EMIT_BYTE(rt, code,0);
 		EMIT_BYTE(rt, code,0);
 
-		writeRoutineCode(rt, ast.expr);
+		result += writeRoutineCode(rt, ast.expr);
 
 		EMIT_BYTE(rt, code,TOY_OPCODE_DIVIDE);
 		EMIT_BYTE(rt, code,TOY_OPCODE_ASSIGN); //squeezed
@@ -365,7 +411,7 @@ static void writeInstructionAssign(Toy_Routine** rt, Toy_AstVarAssign ast) {
 		EMIT_BYTE(rt, code,0);
 		EMIT_BYTE(rt, code,0);
 
-		writeRoutineCode(rt, ast.expr);
+		result += writeRoutineCode(rt, ast.expr);
 
 		EMIT_BYTE(rt, code,TOY_OPCODE_MODULO);
 		EMIT_BYTE(rt, code,TOY_OPCODE_ASSIGN); //squeezed
@@ -379,9 +425,11 @@ static void writeInstructionAssign(Toy_Routine** rt, Toy_AstVarAssign ast) {
 	//4-byte alignment
 	EMIT_BYTE(rt, code,0);
 	EMIT_BYTE(rt, code,0);
+
+	return result;
 }
 
-static void writeInstructionAccess(Toy_Routine** rt, Toy_AstVarAccess ast) {
+static unsigned int writeInstructionAccess(Toy_Routine** rt, Toy_AstVarAccess ast) {
 	//push the name
 	EMIT_BYTE(rt, code, TOY_OPCODE_READ);
 	EMIT_BYTE(rt, code, TOY_VALUE_STRING);
@@ -395,6 +443,8 @@ static void writeInstructionAccess(Toy_Routine** rt, Toy_AstVarAccess ast) {
 	EMIT_BYTE(rt, code,0);
 	EMIT_BYTE(rt, code,0);
 	EMIT_BYTE(rt, code,0);
+
+	return 1;
 }
 
 //routine structure
@@ -402,11 +452,13 @@ static void writeInstructionAccess(Toy_Routine** rt, Toy_AstVarAccess ast) {
 // 	//
 // }
 
-static void writeRoutineCode(Toy_Routine** rt, Toy_Ast* ast) {
+static unsigned int writeRoutineCode(Toy_Routine** rt, Toy_Ast* ast) {
 	if (ast == NULL) {
-		return;
+		return 0;
 	}
 
+	unsigned int result = 0;
+
 	//determine how to write each instruction based on the Ast
 	switch(ast->type) {
 		case TOY_AST_BLOCK:
@@ -417,8 +469,8 @@ static void writeRoutineCode(Toy_Routine** rt, Toy_Ast* ast) {
 				EMIT_BYTE(rt, code, 0);
 			}
 
-			writeRoutineCode(rt, ast->block.child);
+			result += writeRoutineCode(rt, ast->block.child);
-			writeRoutineCode(rt, ast->block.next);
+			result += writeRoutineCode(rt, ast->block.next);
 
 			if (ast->block.innerScope) {
 				EMIT_BYTE(rt, code, TOY_OPCODE_SCOPE_POP);
@@ -429,39 +481,43 @@ static void writeRoutineCode(Toy_Routine** rt, Toy_Ast* ast) {
 			break;
 
 		case TOY_AST_VALUE:
-			writeInstructionValue(rt, ast->value);
+			result += writeInstructionValue(rt, ast->value);
 			break;
 
 		case TOY_AST_UNARY:
-			writeInstructionUnary(rt, ast->unary);
+			result += writeInstructionUnary(rt, ast->unary);
 			break;
 
 		case TOY_AST_BINARY:
-			writeInstructionBinary(rt, ast->binary);
+			result += writeInstructionBinary(rt, ast->binary);
 			break;
 
 		case TOY_AST_COMPARE:
-			writeInstructionCompare(rt, ast->compare);
+			result += writeInstructionCompare(rt, ast->compare);
 			break;
 
 		case TOY_AST_GROUP:
-			writeInstructionGroup(rt, ast->group);
+			result += writeInstructionGroup(rt, ast->group);
+			break;
+
+		case TOY_AST_COMPOUND:
+			result += writeInstructionCompound(rt, ast->compound);
 			break;
 
 		case TOY_AST_PRINT:
-			writeInstructionPrint(rt, ast->print);
+			result += writeInstructionPrint(rt, ast->print);
 			break;
 
 		case TOY_AST_VAR_DECLARE:
-			writeInstructionVarDeclare(rt, ast->varDeclare);
+			result += writeInstructionVarDeclare(rt, ast->varDeclare);
 			break;
 
 		case TOY_AST_VAR_ASSIGN:
-			writeInstructionAssign(rt, ast->varAssign);
+			result += writeInstructionAssign(rt, ast->varAssign);
 			break;
 
 		case TOY_AST_VAR_ACCESS:
-			writeInstructionAccess(rt, ast->varAccess);
+			result += writeInstructionAccess(rt, ast->varAccess);
 			break;
 
 		//meta instructions are disallowed
@@ -481,6 +537,8 @@ static void writeRoutineCode(Toy_Routine** rt, Toy_Ast* ast) {
 			exit(-1);
 			break;
 	}
+
+	return result;
 }
 
 static void* writeRoutine(Toy_Routine* rt, Toy_Ast* ast) {

source/toy_vm.c

@@ -420,6 +420,74 @@ static void processConcat(Toy_VM* vm) {
 	Toy_pushStack(&vm->stack, TOY_VALUE_FROM_STRING(result));
 }
 
+static void processIndex(Toy_VM* vm) {
+	unsigned char count = READ_BYTE(vm); //value[index, length] ; 1[2, 3]
+
+	Toy_Value value = TOY_VALUE_FROM_NULL();
+	Toy_Value index = TOY_VALUE_FROM_NULL();
+	Toy_Value length = TOY_VALUE_FROM_NULL();
+
+	if (count == 3) {
+		length = Toy_popStack(&vm->stack);
+		index = Toy_popStack(&vm->stack);
+		value = Toy_popStack(&vm->stack);
+	}
+	else if (count == 2) {
+		index = Toy_popStack(&vm->stack);
+		value = Toy_popStack(&vm->stack);
+	}
+	else {
+		Toy_error("Incorrect number of elements found in index");
+		//TODO: clear stack
+		return;
+	}
+
+	//process based on value's type
+	if (TOY_VALUE_IS_STRING(value)) {
+		//type checks
+		if (!TOY_VALUE_IS_INTEGER(index)) {
+			Toy_error("Failed to index a string");
+			return;
+		}
+
+		if (!(TOY_VALUE_IS_NULL(length) || TOY_VALUE_IS_INTEGER(length))) {
+			Toy_error("Failed to index-length a string");
+			return;
+		}
+
+		//extract values
+		int i = TOY_VALUE_AS_INTEGER(index);
+		int l = TOY_VALUE_IS_INTEGER(length) ? TOY_VALUE_AS_INTEGER(length) : 1;
+
+		//extract string
+		Toy_String* str = TOY_VALUE_AS_STRING(value);
+		Toy_String* result = NULL;
+
+		//extract cstring, based on type
+		if (str->type == TOY_STRING_LEAF) {
+			const char* cstr = str->as.leaf.data;
+			result = Toy_createStringLength(&vm->stringBucket, cstr + i, l);
+		}
+		else if (str->type == TOY_STRING_NODE) {
+			char* cstr = Toy_getStringRawBuffer(str);
+			result = Toy_createStringLength(&vm->stringBucket, cstr + i, l);
+			free(cstr);
+		}
+		else {
+			fprintf(stderr, TOY_CC_ERROR "ERROR: Unknown string type found in processIndex, exiting\n" TOY_CC_RESET);
+			exit(-1);
+		}
+
+		//finally
+		Toy_pushStack(&vm->stack, TOY_VALUE_FROM_STRING(result));
+	}
+
+	else {
+		fprintf(stderr, TOY_CC_ERROR "ERROR: Unknown value type %d found in processIndex, exiting\n" TOY_CC_RESET, value.type);
+		exit(-1);
+	}
+}
+
 static void process(Toy_VM* vm) {
 	while(true) {
 		Toy_OpcodeType opcode = READ_BYTE(vm);
@@ -494,6 +562,10 @@ static void process(Toy_VM* vm) {
 				processConcat(vm);
 				break;
 
+			case TOY_OPCODE_INDEX:
+				processIndex(vm);
+				break;
+
 			case TOY_OPCODE_PASS:
 			case TOY_OPCODE_ERROR:
 			case TOY_OPCODE_EOF:

tests/cases/test_ast.c

@@ -22,6 +22,7 @@ int test_sizeof_ast_64bit() {
 	TEST_SIZEOF(Toy_AstBinary, 24);
 	TEST_SIZEOF(Toy_AstCompare, 24);
 	TEST_SIZEOF(Toy_AstGroup, 16);
+	TEST_SIZEOF(Toy_AstCompound, 24);
 	TEST_SIZEOF(Toy_AstPrint, 16);
 	TEST_SIZEOF(Toy_AstVarDeclare, 24);
 	TEST_SIZEOF(Toy_AstVarAssign, 24);
@@ -54,6 +55,7 @@ int test_sizeof_ast_32bit() {
 	TEST_SIZEOF(Toy_AstBinary, 16);
 	TEST_SIZEOF(Toy_AstCompare, 16);
 	TEST_SIZEOF(Toy_AstGroup, 8);
+	TEST_SIZEOF(Toy_AstCompound, 16);
 	TEST_SIZEOF(Toy_AstPrint, 8);
 	TEST_SIZEOF(Toy_AstVarDeclare, 12);
 	TEST_SIZEOF(Toy_AstVarAssign, 16);

tests/integrations/test_print.toy

@@ -13,6 +13,11 @@ print "Hello" .. "world!";
 //print with escaped characters
 print "\tHello\nworld";
 
+//print from a leaf string
+print "Hello world"[0,5];
+
+print ("hello" .. "world")[2,6];
+
 //TODO: in the repl, -s to supress output, or -d to print debugging info
 
 //TODO: the `assert` keyword will be useful for these