adding compilation of if-else statements

src/compiler/compile.c

@@ -42,7 +42,8 @@ static _Bool emit_instr_for_node(ExeBuilder *exeb, Node *node, Error *error)
 							OperExprNode *oper = (OperExprNode*) expr;
 
 							for(Node *operand = oper->head; operand; operand = operand->next)
-								emit_instr_for_node(exeb, operand, error);
+								if(!emit_instr_for_node(exeb, operand, error))
+									return 0;
 
 							return ExeBuilder_Append(exeb, error,
 								exprkind_to_opcode(expr->kind), 
@@ -84,10 +85,78 @@ static _Bool emit_instr_for_node(ExeBuilder *exeb, Node *node, Error *error)
 				break;
 			}
 
+			case NODE_IFELSE:
+			{
+				IfElseNode *ifelse = (IfElseNode*) node;
+
+				if(!emit_instr_for_node(exeb, ifelse->condition, error))
+					return 0;
+
+				if(ifelse->false_branch)
+					{
+						Promise *else_offset = Promise_New(ExeBuilder_GetAlloc(exeb), sizeof(long long int));
+						Promise *done_offset = Promise_New(ExeBuilder_GetAlloc(exeb), sizeof(long long int));
+
+						if(else_offset == NULL || done_offset == NULL)
+							{
+								Error_Report(error, 1, "No memory");
+								return 0;
+							}
+
+						Operand op = { .type = OPTP_PROMISE, .as_promise = else_offset };
+						if(!ExeBuilder_Append(exeb, error, OPCODE_JUMPIFNOTANDPOP, &op, 1, node->offset, node->length))
+							return 0;
+
+						if(!emit_instr_for_node(exeb, ifelse->true_branch, error))
+							return 0;
+
+						op = (Operand) { .type = OPTP_PROMISE, .as_promise = done_offset };
+						if(!ExeBuilder_Append(exeb, error, OPCODE_JUMP, &op, 1, node->offset, node->length))
+							return 0;
+
+						long long int temp = ExeBuilder_InstrCount(exeb);
+						Promise_Resolve(else_offset, &temp, sizeof(temp));
+
+						if(!emit_instr_for_node(exeb, ifelse->false_branch, error))
+							return 0;
+
+						temp = ExeBuilder_InstrCount(exeb);
+						Promise_Resolve(done_offset, &temp, sizeof(temp));
+
+						Promise_Free(else_offset);
+						Promise_Free(done_offset);
+					}
+				else
+					{
+						Promise *done_offset = Promise_New(ExeBuilder_GetAlloc(exeb), sizeof(long long int));
+
+						if(done_offset == NULL)
+							{
+								Error_Report(error, 1, "No memory");
+								return 0;
+							}
+
+						if(!ExeBuilder_Append(exeb, error, OPCODE_JUMPIFNOTANDPOP, &(Operand) { .type = OPTP_PROMISE, .as_promise = done_offset }, 1, node->offset, node->length))
+							return 0;
+
+						if(!emit_instr_for_node(exeb, ifelse->true_branch, error))
+							return 0;
+
+						long long int temp = ExeBuilder_InstrCount(exeb);
+						Promise_Resolve(done_offset, &temp, sizeof(temp));
+
+						Promise_Free(done_offset);
+					}
+
+				return 1;
+			}
+
 			default:
 			UNREACHABLE;
-			break;
+			return 0;
 		}
+	UNREACHABLE;
+	return 0;
 }
 
 Executable *compile(AST *ast, BPAlloc *alloc, Error *error)

src/compiler/parse.c

@@ -369,7 +369,7 @@ static Node *parse_string_primary_expression(Context *ctx)
 	assert(ctx != NULL);
 	assert(ctx->token->kind == TSTRING);
 
-	if(current(ctx) == TDONE)
+	if(done(ctx))
 		{
 			Error_Report(ctx->error, 0, "Source ended where a string literal was expected");
 			return NULL;
@@ -493,6 +493,12 @@ static Node *parse_primary_expresion(Context *ctx)
 {
 	assert(ctx != NULL);
 
+	if(done(ctx))
+		{
+			Error_Report(ctx->error, 0, "Source ended where a primary expression was expected");
+			return NULL;
+		}
+
 	switch(current(ctx))
 		{
 			case '+':
@@ -532,7 +538,7 @@ static Node *parse_primary_expresion(Context *ctx)
 				if(node == NULL)
 					return NULL;
 
-				if(current(ctx) == TDONE)
+				if(done(ctx))
 					{
 						Error_Report(ctx->error, 0, "Source ended before \")\", after sub-expression");
 						return NULL;
@@ -823,34 +829,44 @@ static Node *parse_ifelse_statement(Context *ctx)
 {
 	assert(ctx != NULL);
 	assert(ctx->token != NULL);
-	assert(ctx->token->kind == TKWIF);
 
-	ctx->token = ctx->token->next;
-
-	if(ctx->token->kind == TDONE)
+	if(done(ctx))
 		{
-			// ERROR: Source ended after if keyword.
-			// An expression was expected.
-			Error_Report(ctx->error, 0, "Source ended after if keyword. An expression was expected");
+			Error_Report(ctx->error, 0, "Source ended where an if-else statement was expected");
+			return NULL;
+		}
+
+	if(current(ctx) != TKWIF)
+		{
+			Error_Report(ctx->error, 0, "Got unexpected token \"%.*s\" where an if-else statement was expected", ctx->token->length, ctx->src + ctx->token->offset);
 			return NULL;
 		}
 
 	Token *if_token = current_token(ctx);
+	assert(if_token != NULL);
+
+	next(ctx); // Consume the "if" keyword.
 
 	Node *condition = parse_expression(ctx);
-	if(condition == NULL) return NULL;
+	
+	if(condition == NULL) 
+		return NULL;
 
 	Node *true_branch = parse_statement(ctx);
-	if(condition == NULL) return NULL;
+	
+	if(condition == NULL) 
+		return NULL;
 
 	Node *false_branch = NULL;
+
 	if(ctx->token->kind == TKWELSE)
 		{
-			// Consume the "else" token.
-			ctx->token = ctx->token->next;
+			next(ctx); // Consume the "else" token.
 
 			false_branch = parse_statement(ctx);
-			if(false_branch == NULL) return NULL;
+			
+			if(false_branch == NULL) 
+				return NULL;
 		}
 
 	IfElseNode *ifelse;

src/compiler/serialize.c

@@ -126,6 +126,27 @@ static xj_value *convert_node(Node *node, xj_error *error, xj_alloc **alloc)
 				}
 			break;
 
+			case NODE_IFELSE:
+			{
+				IfElseNode *ifelse = (IfElseNode*) node;
+
+				xj_value *condition = convert_node(ifelse->condition, error, alloc);
+				if(condition == NULL) return NULL;
+
+				xj_value *true_branch = convert_node(ifelse->true_branch, error, alloc);
+				if(true_branch == NULL) return NULL;
+
+				xj_value *false_branch = convert_node(ifelse->false_branch, error, alloc);
+				if(false_branch == NULL) return NULL;
+
+				return xj_decodef(error, alloc, 
+					"{"
+					"\t\"node-kind\": \"if-else\", \n"
+					"\t\"condition\": %v, \n"
+					"\t\"true-branch\": %v, \n"
+					"\t\"false-branch\": %v\n"
+					"}", condition, true_branch, false_branch);
+			}
 
 			default:
 			UNREACHABLE;