Implemented typeof and added resetInterpreter()

docs/TODO.txt

@@ -31,17 +31,18 @@ DONE: are compounds shallow or deep copies? Deep copies
 DONE: third output stream, for lexer/parser/compiler/interpreter errors
 DONE: Assertion-based test scripts
 DONE: Import/export keywords
+DONE: A way to check the type of a variable (typeOf keyword)
 
 
 TODO: slice and dot notation around the builtin _index function
 TODO: ternary operator
 TODO: Nullish types?
-TODO: A way to check the type of a variable (typeOf keyword)
-TODO: a = b = c = 1; ?
+TODO: hooks on the external libraries, triggered on import
 TODO: standard library
 TODO: external script runner library
 TODO: document how it all works - book?
 TODO: maximum recursion/function depth
 
 
+NOPE: a = b = c = 1;
 NOPE: functions return a set number of values

docs/spec.md

@@ -49,6 +49,7 @@ The following list of keywords cannot be used as names, due to their significanc
 * string
 * true
 * type
+* typeof
 * var
 * while
 
@@ -163,11 +164,7 @@ var bar = "hello world";
 var buzz;
 ```
 
-Variables can be used in place of values at any time, and can be altered and re-assigned. Multiple variables (which have been previously declared) can be assigned to the same value:
-
-```
-a = b = c = 1;
-```
+Variables can be used in place of values at any time, and can be altered and re-assigned.
 
 ## If-Else
 

scripts/test/imports-and-exports.toy

@@ -32,6 +32,17 @@
 	assert func() == 69, "import/export of functions failed";
 }
 
-//TODO: test that variables retain their types with the typeOf keyword
+//test that variables retain their types with the typeof keyword
+{
+	var t: type = int;
+
+	export t;
+}
+
+{
+	import t;
+
+	assert typeof t == type type, "type retention failed";
+}
 
 print "All good";

source/interpreter.c

@@ -71,40 +71,6 @@ bool parseIdentifierToValue(Interpreter* interpreter, Literal* literalPtr) {
 	return true;
 }
 
-void initInterpreter(Interpreter* interpreter) {
-	//NOTE: separate initialization for exports
-	interpreter->exports = ALLOCATE(LiteralDictionary, 1);
-	initLiteralDictionary(interpreter->exports);
-	interpreter->exportTypes = ALLOCATE(LiteralDictionary, 1);
-	initLiteralDictionary(interpreter->exportTypes);
-
-	//set up the output streams
-	setInterpreterPrint(interpreter, printWrapper);
-	setInterpreterAssert(interpreter, assertWrapper);
-	setInterpreterError(interpreter, errorWrapper);
-}
-
-void freeInterpreter(Interpreter* interpreter) {
-	//BUGFIX: handle scopes/types in the exports
-	for (int i = 0; i < interpreter->exports->capacity; i++) {
-		if (IS_FUNCTION(interpreter->exports->entries[i].key)) {
-			popScope(AS_FUNCTION(interpreter->exports->entries[i].key).scope);
-			AS_FUNCTION(interpreter->exports->entries[i].key).scope = NULL;
-		}
-		if (IS_FUNCTION(interpreter->exports->entries[i].value)) {
-			popScope(AS_FUNCTION(interpreter->exports->entries[i].value).scope);
-			AS_FUNCTION(interpreter->exports->entries[i].value).scope = NULL;
-		}
-	}
-
-	freeLiteralDictionary(interpreter->exports);
-	FREE(LiteralDictionary, interpreter->exports);
-	interpreter->exports = NULL;
-	freeLiteralDictionary(interpreter->exportTypes);
-	FREE(LiteralDictionary, interpreter->exportTypes);
-	interpreter->exportTypes = NULL;
-}
-
 //utilities for the host program
 void setInterpreterPrint(Interpreter* interpreter, PrintFn printOutput) {
 	interpreter->printOutput = printOutput;
@@ -722,6 +688,25 @@ static bool execValCast(Interpreter* interpreter) {
 	return true;
 }
 
+static bool execTypeOf(Interpreter* interpreter) {
+	Literal rhs = popLiteralArray(&interpreter->stack);
+	Literal type = TO_NULL_LITERAL;
+
+	if (IS_IDENTIFIER(rhs)) {
+		type = getScopeType(interpreter->scope, rhs);
+	}
+	else {
+		type = TO_TYPE_LITERAL(rhs.type, false);
+	}
+
+	pushLiteralArray(&interpreter->stack, type);
+
+	freeLiteral(rhs);
+	freeLiteral(type);
+
+	return true;
+}
+
 static bool execCompareEqual(Interpreter* interpreter, bool invert) {
 	Literal rhs = popLiteralArray(&interpreter->stack);
 	Literal lhs = popLiteralArray(&interpreter->stack);
@@ -1469,6 +1454,12 @@ static void execInterpreter(Interpreter* interpreter) {
 				}
 			break;
 
+			case OP_TYPE_OF:
+				if (!execTypeOf(interpreter)) {
+					return;
+				}
+			break;
+
 			case OP_COMPARE_EQUAL:
 				if (!execCompareEqual(interpreter, false)) {
 					return;
@@ -1823,16 +1814,26 @@ static void readInterpreterSections(Interpreter* interpreter) {
 	consumeByte(interpreter, OP_SECTION_END, interpreter->bytecode, &interpreter->count); //terminate the function section
 }
 
-void runInterpreter(Interpreter* interpreter, unsigned char* bytecode, int length) {
-	//check for export zone
-	if (!interpreter->exports || !interpreter->exportTypes) {
-		interpreter->errorOutput("Interpreter has no export region\n");
-		return;
+//exposed functions
+void initInterpreter(Interpreter* interpreter) {
+	//NOTE: separate initialization for exports
+	interpreter->exports = ALLOCATE(LiteralDictionary, 1);
+	initLiteralDictionary(interpreter->exports);
+	interpreter->exportTypes = ALLOCATE(LiteralDictionary, 1);
+	initLiteralDictionary(interpreter->exportTypes);
+
+	//set up the output streams
+	setInterpreterPrint(interpreter, printWrapper);
+	setInterpreterAssert(interpreter, assertWrapper);
+	setInterpreterError(interpreter, errorWrapper);
+
+	interpreter->scope = NULL;
+	resetInterpreter(interpreter);
 }
 
+void runInterpreter(Interpreter* interpreter, unsigned char* bytecode, int length) {
 	//initialize here instead of initInterpreter()
 	initLiteralArray(&interpreter->literalCache);
-	interpreter->scope = pushScope(NULL);
 	interpreter->bytecode = NULL;
 	interpreter->length = 0;
 	interpreter->count = 0;
@@ -1840,14 +1841,6 @@ void runInterpreter(Interpreter* interpreter, unsigned char* bytecode, int lengt
 
 	initLiteralArray(&interpreter->stack);
 
-	//globally available functions
-	injectNativeFn(interpreter, "_set", _set);
-	injectNativeFn(interpreter, "_get", _get);
-	injectNativeFn(interpreter, "_push", _push);
-	injectNativeFn(interpreter, "_pop", _pop);
-	injectNativeFn(interpreter, "_length", _length);
-	injectNativeFn(interpreter, "_clear", _clear);
-
 	interpreter->panic = false;
 
 	//prep the bytecode
@@ -1902,15 +1895,54 @@ void runInterpreter(Interpreter* interpreter, unsigned char* bytecode, int lengt
 		freeLiteral(lit);
 	}
 
-	//free the bytecode
+	//free the bytecode immediately after use
 	FREE_ARRAY(unsigned char, interpreter->bytecode, interpreter->length);
 
 	//free the associated data
 	freeLiteralArray(&interpreter->literalCache);
 	freeLiteralArray(&interpreter->stack);
+}
 
+void resetInterpreter(Interpreter* interpreter) {
 	//free the interpreter scope
 	while(interpreter->scope != NULL) {
 		interpreter->scope = popScope(interpreter->scope);
 	}
+
+	//prep the scope
+	interpreter->scope = pushScope(NULL);
+
+	//globally available functions
+	injectNativeFn(interpreter, "_set", _set);
+	injectNativeFn(interpreter, "_get", _get);
+	injectNativeFn(interpreter, "_push", _push);
+	injectNativeFn(interpreter, "_pop", _pop);
+	injectNativeFn(interpreter, "_length", _length);
+	injectNativeFn(interpreter, "_clear", _clear);
+}
+
+void freeInterpreter(Interpreter* interpreter) {
+	//free the interpreter scope
+	while(interpreter->scope != NULL) {
+		interpreter->scope = popScope(interpreter->scope);
+	}
+
+	//BUGFIX: handle scopes/types in the exports
+	for (int i = 0; i < interpreter->exports->capacity; i++) {
+		if (IS_FUNCTION(interpreter->exports->entries[i].key)) {
+			popScope(AS_FUNCTION(interpreter->exports->entries[i].key).scope);
+			AS_FUNCTION(interpreter->exports->entries[i].key).scope = NULL;
+		}
+		if (IS_FUNCTION(interpreter->exports->entries[i].value)) {
+			popScope(AS_FUNCTION(interpreter->exports->entries[i].value).scope);
+			AS_FUNCTION(interpreter->exports->entries[i].value).scope = NULL;
+		}
+	}
+
+	freeLiteralDictionary(interpreter->exports);
+	FREE(LiteralDictionary, interpreter->exports);
+	interpreter->exports = NULL;
+	freeLiteralDictionary(interpreter->exportTypes);
+	FREE(LiteralDictionary, interpreter->exportTypes);
+	interpreter->exportTypes = NULL;
 }

source/interpreter.h

@@ -41,6 +41,7 @@ void setInterpreterAssert(Interpreter* interpreter, PrintFn assertOutput);
 void setInterpreterError(Interpreter* interpreter, PrintFn errorOutput);
 
 //main access
-void initInterpreter(Interpreter* interpreter);
-void runInterpreter(Interpreter* interpreter, unsigned char* bytecode, int length);
-void freeInterpreter(Interpreter* interpreter);
+void initInterpreter(Interpreter* interpreter); //start of program
+void runInterpreter(Interpreter* interpreter, unsigned char* bytecode, int length); //run the code
+void resetInterpreter(Interpreter* interpreter); //use this to reset the interpreter's environment between runs
+void freeInterpreter(Interpreter* interpreter); //end of program

source/keyword_types.c

@@ -33,6 +33,7 @@ KeywordType keywordTypes[] = {
 	{TOKEN_PRINT,      "print"},
 	{TOKEN_RETURN,     "return"},
 	{TOKEN_TYPE,       "type"},
+	{TOKEN_TYPEOF,     "typeof"},
 	{TOKEN_VAR,        "var"},
 	{TOKEN_WHILE,      "while"},
 

source/literal.c

@@ -624,7 +624,10 @@ void printLiteralCustom(Literal literal, void (printFn)(const char*)) {
 
 				case LITERAL_FUNCTION:
 					printToBuffer("function");
-					//TODO: how to print a function
+				break;
+
+				case LITERAL_FUNCTION_NATIVE:
+					printToBuffer("native");
 				break;
 
 				case LITERAL_IDENTIFIER:

source/opcodes.h

@@ -43,6 +43,7 @@ typedef enum Opcode {
 	OP_VAR_MODULO_ASSIGN,
 
 	OP_TYPE_CAST,		//temporarily change a type of an atomic value
+	OP_TYPE_OF,			//get the type of a variable
 
 	OP_IMPORT,
 	OP_EXPORT,

source/parser.c

@@ -136,6 +136,13 @@ static Opcode forceType(Parser* parser, Node** nodeHandle) {
 	return OP_EOF;
 }
 
+static Opcode typeOf(Parser* parser, Node** nodeHandle) {
+	Node* rhs = NULL;
+	parsePrecedence(parser, &rhs, PREC_TERNARY);
+	emitNodeUnary(nodeHandle, OP_TYPE_OF, rhs);
+	return OP_EOF;
+}
+
 static Opcode compound(Parser* parser, Node** nodeHandle) {
 	//read either an array or a dictionary into a literal node
 
@@ -730,6 +737,7 @@ ParseRule parseRules[] = { //must match the token types
 	{NULL, NULL, PREC_NONE},// TOKEN_PRINT,
 	{NULL, NULL, PREC_NONE},// TOKEN_RETURN,
 	{forceType, NULL, PREC_PRIMARY},// TOKEN_TYPE,
+	{typeOf, NULL, PREC_CALL},// TOKEN_TYPEOF,
 	{NULL, NULL, PREC_NONE},// TOKEN_VAR,
 	{NULL, NULL, PREC_NONE},// TOKEN_WHILE,
 
@@ -1044,14 +1052,14 @@ static void blockStmt(Parser* parser, Node** nodeHandle) {
 		//process the grammar rule for this line
 		declaration(parser, &node);
 
-		//BUGFIX: statements no longer require an existing node
-		((*nodeHandle)->block.nodes[(*nodeHandle)->block.count++]) = *node;
-		FREE(Node, node); //simply free the tmp node
-
 		// Ground floor: perfumery / Stationery and leather goods / Wigs and haberdashery / Kitchenware and food / Going up!
 		if (parser->panic) {
 			return;
 		}
+
+		//BUGFIX: statements no longer require an existing node
+		((*nodeHandle)->block.nodes[(*nodeHandle)->block.count++]) = *node;
+		FREE(Node, node); //simply free the tmp node
 	}
 }
 

source/token_types.h

@@ -31,6 +31,7 @@ typedef enum TokenType {
 	TOKEN_PRINT,
 	TOKEN_RETURN,
 	TOKEN_TYPE,
+	TOKEN_TYPEOF,
 	TOKEN_VAR,
 	TOKEN_WHILE,
 

test/test_interpreter.c

@@ -210,6 +210,9 @@ int main() {
 		setInterpreterPrint(&interpreter, noPrintFn);
 
 		runInterpreter(&interpreter, exportBinary, exportSize); //automatically frees the binary data
+
+		resetInterpreter(&interpreter);
+
 		runInterpreter(&interpreter, importBinary, importSize); //automatically frees the binary data
 
 		freeInterpreter(&interpreter);