Implemented scopes

scripts/testificate.toy

@@ -0,0 +1,22 @@
+
+//normal scope stuff
+var answer = 42;
+print answer;
+
+{
+	var answer = 7;
+	print answer;
+}
+
+print answer;
+
+//I wonder if...
+var question = 42;
+print question;
+
+{
+	var question = question;
+	print question;
+}
+
+print question;

source/toy_ast.c

@@ -4,6 +4,7 @@ void Toy_private_initAstBlock(Toy_Bucket** bucketHandle, Toy_Ast** astHandle) {
 	Toy_Ast* tmp = (Toy_Ast*)Toy_partitionBucket(bucketHandle, sizeof(Toy_Ast));
 
 	tmp->type = TOY_AST_BLOCK;
+	tmp->block.innerScope = false;
 	tmp->block.child = NULL;
 	tmp->block.next = NULL;
 	tmp->block.tail = NULL;

source/toy_ast.h

@@ -69,6 +69,7 @@ typedef union Toy_Ast Toy_Ast;
 
 typedef struct Toy_AstBlock {
 	Toy_AstType type;
+	bool innerScope;
 	Toy_Ast* child; //begin encoding the line
 	Toy_Ast* next; //'next' is either an AstBlock or null
 	Toy_Ast* tail; //'tail' - either points to the tail of the current list, or null; only used by the head of a list as an optimisation

source/toy_opcodes.h

@@ -33,6 +33,9 @@ typedef enum Toy_OpcodeType {
 	//control instructions
 	TOY_OPCODE_RETURN,
 
+	TOY_OPCODE_SCOPE_PUSH,
+	TOY_OPCODE_SCOPE_POP,
+
 	//various action instructions
 	TOY_OPCODE_PRINT,
 	TOY_OPCODE_CONCAT,

source/toy_parser.c

@@ -565,6 +565,9 @@ static void makeExpr(Toy_Bucket** bucketHandle, Toy_Parser* parser, Toy_Ast** ro
 	parsePrecedence(bucketHandle, parser, rootHandle, PREC_ASSIGNMENT);
 }
 
+//forward declarations
+static void makeBlockStmt(Toy_Bucket** bucketHandle, Toy_Parser* parser, Toy_Ast** rootHandle);
+
 static void makePrintStmt(Toy_Bucket** bucketHandle, Toy_Parser* parser, Toy_Ast** rootHandle) {
 	makeExpr(bucketHandle, parser, rootHandle);
 	Toy_private_emitAstPrint(bucketHandle, rootHandle);
@@ -608,7 +611,14 @@ static void makeVariableDeclarationStmt(Toy_Bucket** bucketHandle, Toy_Parser* p
 }
 
 static void makeStmt(Toy_Bucket** bucketHandle, Toy_Parser* parser, Toy_Ast** rootHandle) {
-	//block
+	//inner scope
+	if (match(parser, TOY_TOKEN_OPERATOR_BRACE_LEFT)) {
+		makeBlockStmt(bucketHandle, parser, rootHandle);
+		consume(parser, TOY_TOKEN_OPERATOR_BRACE_RIGHT, "Expected '}' at the end of block scope");
+		(*rootHandle)->block.innerScope = true;
+		return;
+	}
+
 	//assert
 	//if-then-else
 	//while-then
@@ -619,7 +629,7 @@ static void makeStmt(Toy_Bucket** bucketHandle, Toy_Parser* parser, Toy_Ast** ro
 	//import
 
 	//check for empty lines
-	if (match(parser, TOY_TOKEN_OPERATOR_SEMICOLON)) {
+	else if (match(parser, TOY_TOKEN_OPERATOR_SEMICOLON)) {
 		Toy_private_emitAstPass(bucketHandle, rootHandle);
 		return;
 	}
@@ -658,7 +668,7 @@ static void makeBlockStmt(Toy_Bucket** bucketHandle, Toy_Parser* parser, Toy_Ast
 	Toy_private_initAstBlock(bucketHandle, rootHandle);
 
 	//read a series of statements into the block
-	while (!match(parser, TOY_TOKEN_EOF)) {
+	while (parser->current.type != TOY_TOKEN_OPERATOR_BRACE_RIGHT && !match(parser, TOY_TOKEN_EOF)) {
 		//process the grammar rules
 		Toy_Ast* stmt = NULL;
 		makeDeclarationStmt(bucketHandle, parser, &stmt);
@@ -695,6 +705,11 @@ Toy_Ast* Toy_scanParser(Toy_Bucket** bucketHandle, Toy_Parser* parser) {
 
 	makeBlockStmt(bucketHandle, parser, &rootHandle);
 
+	//don't emit this error if we're already panicking
+	if (parser->panic != true && parser->previous.type != TOY_TOKEN_EOF) {
+		printError(parser, parser->previous, "Expected 'EOF' and the end of the parser scan (possibly an extra '}' was found)");
+	}
+
 	return rootHandle;
 }
 

source/toy_routine.c

@@ -410,8 +410,22 @@ static void writeRoutineCode(Toy_Routine** rt, Toy_Ast* ast) {
 	//determine how to write each instruction based on the Ast
 	switch(ast->type) {
 		case TOY_AST_BLOCK:
+			if (ast->block.innerScope) {
+				EMIT_BYTE(rt, code, TOY_OPCODE_SCOPE_PUSH);
+				EMIT_BYTE(rt, code, 0);
+				EMIT_BYTE(rt, code, 0);
+				EMIT_BYTE(rt, code, 0);
+			}
+
 			writeRoutineCode(rt, ast->block.child);
 			writeRoutineCode(rt, ast->block.next);
+
+			if (ast->block.innerScope) {
+				EMIT_BYTE(rt, code, TOY_OPCODE_SCOPE_POP);
+				EMIT_BYTE(rt, code, 0);
+				EMIT_BYTE(rt, code, 0);
+				EMIT_BYTE(rt, code, 0);
+			}
 			break;
 
 		case TOY_AST_VALUE:

source/toy_vm.c

@@ -482,6 +482,14 @@ static void process(Toy_VM* vm) {
 				//temp terminator
 				return;
 
+			case TOY_OPCODE_SCOPE_PUSH:
+				vm->scope = Toy_pushScope(&vm->scopeBucket, vm->scope);
+				break;
+
+			case TOY_OPCODE_SCOPE_POP:
+				vm->scope = Toy_popScope(vm->scope);
+				break;
+
 			//various action instructions
 			case TOY_OPCODE_PRINT:
 				processPrint(vm);

tests/cases/test_ast.c

@@ -48,7 +48,7 @@ int test_sizeof_ast_32bit() {
 
 	//run for each type
 	TEST_SIZEOF(Toy_AstType, 4);
-	TEST_SIZEOF(Toy_AstBlock, 16);
+	TEST_SIZEOF(Toy_AstBlock, 20);
 	TEST_SIZEOF(Toy_AstValue, 12);
 	TEST_SIZEOF(Toy_AstUnary, 12);
 	TEST_SIZEOF(Toy_AstBinary, 16);
@@ -61,7 +61,7 @@ int test_sizeof_ast_32bit() {
 	TEST_SIZEOF(Toy_AstPass, 4);
 	TEST_SIZEOF(Toy_AstError, 4);
 	TEST_SIZEOF(Toy_AstEnd, 4);
-	TEST_SIZEOF(Toy_Ast, 16);
+	TEST_SIZEOF(Toy_Ast, 20);
 
 #undef TEST_SIZEOF
 

tests/integrations/test_scopes.toy

@@ -0,0 +1,19 @@
+//shadowing
+var answer = 42;
+print answer; //42
+{
+	    var answer = 7;
+		    print answer; //7
+}
+print answer; //42
+
+//rebinding
+var question = 42;
+print question; //42
+{
+	    var question = question;
+		    print question; //42
+}
+print question; //42
+
+//TODO: scope test case

tests/integrations/test_variables.toy

@@ -7,15 +7,13 @@ var empty;
 //assign a previously existing variable
 answer = 6 * 9;
 
+//access a variable
 answer = answer + 1;
 
+//compound assignments
 answer += 5;
-
 answer -= 5;
-
 answer *= 9;
-
 answer /= 2;
-
 answer %= 10;