Added scopes using '{}' symbols, read more

I've also added a new literal type called 'identifier'. This will be
used for variable names, and has a type mask embedded in it.

scripts/example.toy

@@ -14,7 +14,16 @@ print -69;
 print -4.20;
 print 2 + (3 * 3);
 
-assert true, "This won't be seen";
+//test scopes
+{
+	print "This statement is within a scope.";
+	{
+		print "This is a deeper scope.";
+	}
+}
+print "Back to the outer scope.";
 
+//test asserts
+assert true, "This won't be seen";
 assert false, "This is an error";
 

source/compiler.c

@@ -33,7 +33,7 @@ void writeCompiler(Compiler* compiler, Node* node) {
 	switch(node->type) {
 		//TODO: more types, like variables, etc.
 		case NODE_ERROR: {
-			printf("[internal] NODE_ERROR encountered in writeCompiler()");
+			fprintf(stderr, "[Internal] NODE_ERROR encountered in writeCompiler()");
 			compiler->bytecode[compiler->count++] = OP_EOF; //1 byte
 		}
 		break;
@@ -80,6 +80,16 @@ void writeCompiler(Compiler* compiler, Node* node) {
 			compiler->bytecode[compiler->count++] = (unsigned char)OP_GROUPING_END; //1 byte
 		break;
 
+		case NODE_BLOCK:
+			compiler->bytecode[compiler->count++] = (unsigned char)OP_SCOPE_BEGIN; //1 byte
+
+			for (int i = 0; i < node->block.count; i++) {
+				writeCompiler(compiler, &(node->block.nodes[i]));
+			}
+
+			compiler->bytecode[compiler->count++] = (unsigned char)OP_SCOPE_END; //1 byte
+		break;
+
 		//TODO: conditional
 	}
 }
@@ -202,6 +212,10 @@ unsigned char* collateCompiler(Compiler* compiler, int* size) {
 				emitByte(&collation, &capacity, &count, '\0'); //terminate the string
 			}
 			break;
+
+			default:
+				fprintf(stderr, "[Internal] Unknown literal type encountered within literal cache\n");
+				return NULL;
 		}
 	}
 

source/interpreter.c

@@ -19,6 +19,7 @@ static void stderrWrapper(const char* output) {
 
 void initInterpreter(Interpreter* interpreter, unsigned char* bytecode, int length) {
 	initLiteralArray(&interpreter->literalCache);
+	interpreter->scope = pushScope(NULL);
 	interpreter->bytecode = bytecode;
 	interpreter->length = length;
 	interpreter->count = 0;
@@ -31,6 +32,7 @@ void initInterpreter(Interpreter* interpreter, unsigned char* bytecode, int leng
 
 void freeInterpreter(Interpreter* interpreter) {
 	freeLiteralArray(&interpreter->literalCache);
+	interpreter->scope = popScope(interpreter->scope);
 	FREE_ARRAY(char, interpreter->bytecode, interpreter->length);
 	freeLiteralArray(&interpreter->stack);
 }
@@ -283,6 +285,15 @@ static void execInterpreter(Interpreter* interpreter) {
 			case OP_GROUPING_END:
 				return;
 
+			//scope
+			case OP_SCOPE_BEGIN:
+				interpreter->scope = pushScope(interpreter->scope);
+			break;
+
+			case OP_SCOPE_END:
+				interpreter->scope = popScope(interpreter->scope);
+			break;
+
 			default:
 				printf("Unknown opcode found %d, terminating\n", opcode);
 				printLiteralArray(&interpreter->stack, "\n");

source/interpreter.h

@@ -4,12 +4,14 @@
 
 #include "literal_array.h"
 #include "literal_dictionary.h"
+#include "scope.h"
 
 typedef void (*PrintFn)(const char*);
 
 //the interpreter acts depending on the bytecode instructions
 typedef struct Interpreter {
 	LiteralArray literalCache; //generally doesn't change after initialization
+	Scope* scope;
 	unsigned char* bytecode;
 	int length;
 	int count;

source/literal.c

@@ -43,9 +43,16 @@ void printLiteralCustom(Literal literal, void (printFn)(const char*)) {
 		}
 		break;
 
+		case LITERAL_IDENTIFIER: {
+			char buffer[256];
+			snprintf(buffer, 256, "%.*s", STRLEN_I(literal), AS_IDENTIFIER(literal));
+			printFn(buffer);
+		}
+		break;
+
 		default:
 			//should never bee seen
-			fprintf(stderr, "[Internal] Unrecognized literal type: %d", literal.type);
+			fprintf(stderr, "[Internal] Unrecognized literal type in print: %d\n", literal.type);
 	}
 }
 
@@ -60,8 +67,12 @@ 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));
 }
 
-Literal _toStringLiteral(char* cstr) {
+Literal _toStringLiteral(char* str) {
-	return ((Literal){LITERAL_STRING, { .string.ptr = (char*)cstr, .string.length = strlen((char*)cstr) }});
+	return ((Literal){LITERAL_STRING, {.string.ptr = (char*)str, .string.length = strlen((char*)str)}});
+}
+
+Literal _toIdentifierLiteral(char* str, unsigned char types) {
+	return ((Literal){LITERAL_IDENTIFIER,{.identifier.ptr = (char*)str,.identifier.length = strlen((char*)str),.identifier.types = types}});
 }
 
 char* copyString(char* original, int length) {
@@ -102,9 +113,15 @@ bool literalsAreEqual(Literal lhs, Literal rhs) {
 			}
 			return !strncmp(AS_STRING(lhs), AS_STRING(rhs), STRLEN(lhs));
 
+		case LITERAL_IDENTIFIER:
+			if (STRLEN_I(lhs) != STRLEN_I(rhs)) {
+				return false;
+			}
+			return !strncmp(AS_IDENTIFIER(lhs), AS_IDENTIFIER(rhs), STRLEN_I(lhs));
+
 		default:
 			//should never bee seen
-			fprintf(stderr, "[Internal] Unrecognized literal type: %d", lhs.type);
+			fprintf(stderr, "[Internal] Unrecognized literal type: %d\n", lhs.type);
 			return false;
 	}
 }
@@ -145,9 +162,12 @@ int hashLiteral(Literal lit) {
 		case LITERAL_STRING:
 			return hashString(AS_STRING(lit), STRLEN(lit));
 
+		case LITERAL_IDENTIFIER:
+			return hashString(AS_IDENTIFIER(lit), STRLEN_I(lit));
+
 		default:
 			//should never bee seen
-			fprintf(stderr, "[Internal] Unrecognized literal type in hash: %d", lit.type);
+			fprintf(stderr, "[Internal] Unrecognized literal type in hash: %d\n", lit.type);
 			return 0;
 	}
 }

source/literal.h

@@ -13,6 +13,7 @@ typedef enum {
 	// LITERAL_ARRAY,
 	// LITERAL_DICTIONARY,
 	// LITERAL_FUNCTION,
+	LITERAL_IDENTIFIER,
 } LiteralType;
 
 typedef struct {
@@ -23,13 +24,19 @@ typedef struct {
 		float number;
 		struct {
 			char* ptr;
-			int length; //could possibly cut it down further by removing this
+			int length;
 		} string;
 
 		// //experimental
 		// void* array;
 		// void* dictionary;
 		// void* function;
+
+		struct { //for variable names
+            char* ptr;
+            int length;
+			unsigned char types;
+        } identifier;
 	} as;
 } Literal;
 
@@ -41,24 +48,46 @@ typedef struct {
 #define IS_ARRAY(value)						((value).type == LITERAL_ARRAY)
 #define IS_DICTIONARY(value)				((value).type == LITERAL_DICTIONARY)
 #define IS_FUNCTION(value)					((value).type == LITERAL_FUNCTION)
+#define IS_IDENTIFIER(value)				((value).type == LITERAL_IDENTIFIER)
 
 #define AS_BOOLEAN(value)					((value).as.boolean)
 #define AS_INTEGER(value)					((value).as.integer)
 #define AS_FLOAT(value)						((value).as.number)
 #define AS_STRING(value)					((value).as.string.ptr)
-// #define AS_ARRAY_PTR(value)
+// #define AS_ARRAY(value)
-// #define AS_DICTIONARY_PTR(value)
+// #define AS_DICTIONARY(value)
-// #define AS_FUNCTION_PTR(value)		((Function*)((value).as.function))
+// #define AS_FUNCTION(value)
+#define AS_IDENTIFIER(value)				((value).as.identifier.ptr)
 
 #define TO_NULL_LITERAL						((Literal){LITERAL_NULL,		{ .integer = 0 }})
 #define TO_BOOLEAN_LITERAL(value)			((Literal){LITERAL_BOOLEAN,		{ .boolean = value }})
 #define TO_INTEGER_LITERAL(value)			((Literal){LITERAL_INTEGER,		{ .integer = value }})
 #define TO_FLOAT_LITERAL(value)				((Literal){LITERAL_FLOAT,		{ .number = value }})
 #define TO_STRING_LITERAL(value)			_toStringLiteral(value)
-// #define TO_ARRAY_PTR
+// #define TO_ARRAY_LITERAL
-// #define TO_DICTIONARY_PTR
+// #define TO_DICTIONARY_LITERAL
-// #define TO_FUNCTION_PTR(value)		((Literal){LITERAL_FUNCTION,	{ .function = (Function*)value }})
+// #define TO_FUNCTION_LITERAL
+#define TO_IDENTIFIER_LITERAL(value, types)	_toIdentifierLiteral(value, types)
 
+#define MASK(x) 			(1 >> (x))
+#define TYPE_CONST			0
+#define TYPE_BOOLEAN		1
+#define TYPE_INTEGER		2
+#define TYPE_FLOAT			3
+#define TYPE_STRING			4
+#define TYPE_ARRAY			5
+#define TYPE_DICTIONARY		6
+#define TYPE_FUNCTION		7
+#define MASK_CONST			(MASK(TYPE_CONST))
+#define MASK_BOOLEAN		(MASK(TYPE_BOOLEAN))
+#define MASK_INTEGER		(MASK(TYPE_INTEGER))
+#define MASK_FLOAT			(MASK(TYPE_FLOAT))
+#define MASK_STRING			(MASK(TYPE_STRING))
+#define MASK_ARRAY			(MASK(TYPE_ARRAY))
+#define MASK_DICTIONARY		(MASK(TYPE_DICTIONARY))
+#define MASK_FUNCTION		(MASK(TYPE_FUNCTION))
+
+//utils
 void printLiteral(Literal literal);
 void printLiteralCustom(Literal literal, void (printFn)(const char*));
 void freeLiteral(Literal literal);
@@ -66,10 +95,13 @@ void freeLiteral(Literal literal);
 #define IS_TRUTHY(x) _isTruthy(x)
 
 #define STRLEN(lit)		((lit).as.string.length)
+#define STRLEN_I(lit)	((lit).as.identifier.length)
+#define TYPES(lit)		((lit).as.identifier.types)
 
 //BUGFIX: macros are not functions
 bool _isTruthy(Literal x);
-Literal _toStringLiteral(char* cstr);
+Literal _toStringLiteral(char* str);
+Literal _toIdentifierLiteral(char* str, unsigned char types);
 
 //utils
 char* copyString(char* original, int length);

source/literal_dictionary.c

@@ -199,3 +199,8 @@ void removeLiteralDictionary(LiteralDictionary* dictionary, Literal key) {
 	}
 }
 
+bool existsLiteralDictionary(LiteralDictionary* dictionary, Literal key) {
+	//null & not tombstoned
+	_entry* entry = getEntryArray(dictionary->entries, dictionary->capacity, key, hashLiteral(key), false);
+	return !(IS_NULL(entry->key) && IS_NULL(entry->value));
+}

source/literal_dictionary.h

@@ -23,3 +23,5 @@ void freeLiteralDictionary(LiteralDictionary* dictionary);
 void setLiteralDictionary(LiteralDictionary* dictionary, Literal key, Literal value);
 Literal getLiteralDictionary(LiteralDictionary* dictionary, Literal key);
 void removeLiteralDictionary(LiteralDictionary* dictionary, Literal key);
+
+bool existsLiteralDictionary(LiteralDictionary* dictionary, Literal key);

source/node.c

@@ -3,6 +3,7 @@
 #include "memory.h"
 
 #include <stdio.h>
+#include <stdlib.h>
 
 void freeNode(Node* node) {
 	//don't free a NULL node
@@ -31,6 +32,12 @@ void freeNode(Node* node) {
 		case NODE_GROUPING:
 			freeNode(node->grouping.child);
 		break;
+
+		case NODE_BLOCK:
+			for (int i = 0; i < node->block.count; i++) {
+				freeNode(node->block.nodes + i);
+			}
+		break;
 	}
 
 	FREE(Node, node);
@@ -73,6 +80,17 @@ void emitNodeGrouping(Node** nodeHandle) {
 	*nodeHandle = tmp;
 }
 
+void emitNodeBlock(Node** nodeHandle) {
+	Node* tmp = ALLOCATE(Node, 1);
+
+	tmp->type = NODE_BLOCK;
+	tmp->block.nodes = NULL;
+	tmp->block.capacity = 0;
+	tmp->block.count = 0;
+
+	*nodeHandle = tmp;
+}
+
 void printNode(Node* node) {
 	if (node == NULL) {
 		return;
@@ -106,5 +124,15 @@ void printNode(Node* node) {
 			printNode(node->grouping.child);
 			printf(")");
 		break;
+
+		case NODE_BLOCK:
+			printf("{\n");
+
+			for (int i = 0; i < node->block.count; i++) {
+				printNode(&(node->block.nodes[i]));
+			}
+
+			printf("}\n");
+		break;
 	}
 }

source/node.h

@@ -12,6 +12,7 @@ typedef enum NodeType {
 	NODE_UNARY, //one child
 	NODE_BINARY, //two children, left and right
 	NODE_GROUPING, //one child
+	NODE_BLOCK, //contains bytecode
 	// NODE_CONDITIONAL, //three children: conditional, then path, else path
 } NodeType;
 
@@ -38,12 +39,20 @@ typedef struct NodeGrouping {
 	Node* child;
 } NodeGrouping;
 
+typedef struct NodeBlock {
+	NodeType type;
+	Node* nodes;
+	int capacity;
+	int count;
+} NodeBlock;
+
 union _node {
 	NodeType type;
 	NodeLiteral atomic;
 	NodeUnary unary;
 	NodeBinary binary;
 	NodeGrouping grouping;
+	NodeBlock block;
 };
 
 void freeNode(Node* node);
@@ -51,6 +60,7 @@ void emitNodeLiteral(Node** nodeHandle, Literal literal);
 void emitNodeUnary(Node** nodeHandle, Opcode opcode);
 void emitNodeBinary(Node** nodeHandle, Node* rhs, Opcode opcode);
 void emitNodeGrouping(Node** nodeHandle);
+void emitNodeBlock(Node** nodeHandle);
 
 void printNode(Node* node);
 

source/opcodes.h

@@ -20,6 +20,8 @@ typedef enum Opcode {
 	OP_MODULO,
 	OP_GROUPING_BEGIN,
 	OP_GROUPING_END,
+	OP_SCOPE_BEGIN,
+	OP_SCOPE_END,
 
 	//meta
 	OP_SECTION_END,

source/parser.c

@@ -111,6 +111,7 @@ typedef struct {
 ParseRule parseRules[];
 
 //forward declarations
+static void declaration(Parser* parser, Node** nodeHandle);
 static void parsePrecedence(Parser* parser, Node** nodeHandle, PrecedenceRule rule);
 
 //the expression rules
@@ -523,6 +524,37 @@ static void expression(Parser* parser, Node** nodeHandle) {
 }
 
 //statements
+static void blockStmt(Parser* parser, Node* node) {
+	//init
+	node->type = NODE_BLOCK;
+	node->block.nodes = NULL;
+	node->block.capacity = 0;
+	node->block.count = 0;
+
+	//sub-scope, compile it and push it up in a node
+	while (!match(parser, TOKEN_BRACE_RIGHT)) {
+		if (node->block.capacity < node->block.count + 1) {
+			int oldCapacity = node->block.capacity;
+
+			node->block.capacity = GROW_CAPACITY(oldCapacity);
+			node->block.nodes = GROW_ARRAY(Node, node->block.nodes, oldCapacity, node->block.capacity);
+		}
+
+		//use the next node in sequence
+		node->block.nodes[node->block.count].type = NODE_ERROR; //BUGFIX: so freeing won't break the damn thing
+
+		Node* ptr = &(node->block.nodes[node->block.count++]);
+
+		//process the grammar rule for this line
+		declaration(parser, &ptr);
+
+		// Ground floor: perfumery / Stationery and leather goods / Wigs and haberdashery / Kitchenware and food / Going up!
+		if (parser->panic) {
+			return;
+		}
+	}
+}
+
 static void printStmt(Parser* parser, Node* node) {
 	//set the node info
 	node->type = NODE_UNARY;
@@ -550,6 +582,12 @@ static void expressionStmt(Parser* parser, Node* node) {
 }
 
 static void statement(Parser* parser, Node* node) {
+	//block
+	if (match(parser, TOKEN_BRACE_LEFT)) {
+		blockStmt(parser, node);
+		return;
+	}
+
 	//print
 	if (match(parser, TOKEN_PRINT)) {
 		printStmt(parser, node);
@@ -567,14 +605,9 @@ static void statement(Parser* parser, Node* node) {
 }
 
 static void declaration(Parser* parser, Node** nodeHandle) {
-	statement(parser, *nodeHandle);
+	//TODO: variable declarations
 
-	if (parser->panic) {
+	statement(parser, *nodeHandle);
-		synchronize(parser);
-		//return an error node for this iteration
-		*nodeHandle = ALLOCATE(Node, 1);
-		(*nodeHandle)->type = NODE_ERROR;
-	}
 }
 
 //exposed functions
@@ -610,5 +643,12 @@ Node* scanParser(Parser* parser) {
 	//process the grammar rule for this line
 	declaration(parser, &node);
 
+	if (parser->panic) {
+		synchronize(parser);
+		//return an error node for this iteration
+		node = ALLOCATE(Node, 1);
+		node->type = NODE_ERROR;
+	}
+
 	return node;
 }

source/repl_main.c

@@ -194,23 +194,8 @@ void debug() {
 
 	initLiteralDictionary(&dictionary);
 
-	for (int i = 0; i < 100; i++) {
+	setLiteralDictionary(&dictionary, TO_IDENTIFIER_LITERAL("variable", MASK_INTEGER), TO_INTEGER_LITERAL(2));
-		setLiteralDictionary(&dictionary, TO_INTEGER_LITERAL(i), TO_INTEGER_LITERAL(i * 2));
+	printLiteral( getLiteralDictionary(&dictionary, TO_IDENTIFIER_LITERAL("variable", MASK_INTEGER)) );
-	}
-
-	for (int i = 0; i < 100; i++) {
-		printf("%d: ", i);
-		printLiteral( getLiteralDictionary(&dictionary, TO_INTEGER_LITERAL(i)) );
-		printf("\n");
-	}
-
-	printf("-------------");
-
-	for (int i = 0; i < dictionary.capacity; i++) {
-		printf("%d: ", i);
-		printLiteral(dictionary.entries[i].key);
-		printf("\n");
-	}
 
 	freeLiteralDictionary(&dictionary);
 }

source/scope.c

@@ -0,0 +1,86 @@
+#include "scope.h"
+
+#include "memory.h"
+
+//run up the ancestor chain, freeing anything with 0 references left
+static void freeAncestorChain(Scope* scope) {
+	scope->references--;
+
+	//free scope chain
+	if (scope->ancestor != NULL) {
+		freeAncestorChain(scope->ancestor);
+	}
+
+	if (scope->references > 0) {
+		return;
+	}
+
+	freeLiteralDictionary(&scope->variables);
+
+	FREE(Scope, scope);
+}
+
+//exposed functions
+Scope* pushScope(Scope* ancestor) {
+	Scope* scope = ALLOCATE(Scope, 1);
+	scope->ancestor = ancestor;
+	initLiteralDictionary(&scope->variables);
+
+	//tick up all scope reference counts
+	scope->references = 0;
+	for (Scope* ptr = scope; ptr; ptr = ptr->ancestor) {
+		ptr->references++;
+	}
+
+	return scope;
+}
+
+Scope* popScope(Scope* scope) {
+	Scope* ret = scope->ancestor;
+
+	freeAncestorChain(scope);
+
+	return ret;
+}
+
+//returns false if error
+bool declareScopeVariable(Scope* scope, Literal key) {
+	//don't redefine a variable within this scope
+	if (existsLiteralDictionary(&scope->variables, key)) {
+		return false;
+	}
+
+	setLiteralDictionary(&scope->variables, key, TO_NULL_LITERAL);
+	return true;
+}
+
+//return false if undefined
+bool setScopeVariable(Scope* scope, Literal key, Literal value) {
+	//dead end
+	if (scope == NULL) {
+		return false;
+	}
+
+	//if it's not in this scope, keep searching up the chain
+	if (!existsLiteralDictionary(&scope->variables, key)) {
+		return setScopeVariable(scope->ancestor, key, value);
+	}
+
+	setLiteralDictionary(&scope->variables, key, value);
+	return true;
+}
+
+bool getScopeVariable(Scope* scope, Literal key, Literal* valueHandle) {
+	//dead end
+	if (scope == NULL) {
+		return false;
+	}
+
+	//if it's not in this scope, keep searching up the chain
+	if (!existsLiteralDictionary(&scope->variables, key)) {
+		return getScopeVariable(scope->ancestor, key, valueHandle);
+	}
+
+	*valueHandle = getLiteralDictionary(&scope->variables, key);
+	return true;
+}

source/scope.h

@@ -0,0 +1,21 @@
+#pragma once
+
+#include "common.h"
+#include "literal_dictionary.h"
+
+typedef struct Scope {
+	LiteralDictionary variables;
+	struct Scope* ancestor;
+	int references; //how many scopes point here
+} Scope;
+
+Scope* pushScope(Scope* scope);
+Scope* popScope(Scope* scope);
+
+//returns false if error
+bool declareScopeVariable(Scope* scope, Literal key);
+
+//return false if undefined
+bool setScopeVariable(Scope* scope, Literal key, Literal value);
+bool getScopeVariable(Scope* scope, Literal key, Literal* value);
+