new -> operator

src/lib/common/executable.c

@@ -99,6 +99,7 @@ static const InstrInfo instr_table[] = {
 	INSTR(CHECKTYPE, OPTP_INT, OPTP_STRING)
 	INSTR(CALL, OPTP_INT, OPTP_INT)
 	INSTR(SELECT)
+	INSTR(SELECT2)
 	INSTR(INSERT)
 	INSTR(INSERT2)
 	INSTR(PUSHINT, OPTP_INT)
@@ -520,6 +521,13 @@ _Bool ExeBuilder_Append(ExeBuilder *exeb, Error *error, Opcode opcode, Operand *
 
 	const InstrInfo *info = Executable_GetInstrByOpcode(opcode);
 
+#ifndef NDEBUG
+	if (info == NULL) {
+		Error_Report(error, 1, "Missing instruction table entry for opcode");
+		return 0;
+	}
+#endif
+
 	if(opc != info->opcount)
 	{
 		// ERROR: Too many operands were provided.

src/lib/common/executable.h

@@ -74,6 +74,7 @@ typedef enum {
 	OPCODE_POP,
 	OPCODE_CALL,
 	OPCODE_SELECT,
+	OPCODE_SELECT2,
 	OPCODE_INSERT,
 	OPCODE_INSERT2,
 	OPCODE_PUSHINT,

src/lib/compiler/ASTi.h

@@ -65,6 +65,7 @@ typedef enum {
 	EXPR_OR,
 	EXPR_NOT,
 
+	EXPR_ARW,
 	EXPR_ASS,
 	EXPR_INT,
 	EXPR_MAP,

src/lib/compiler/codegen.c

@@ -198,19 +198,34 @@ static void emitInstrForFuncCallNode(CodegenContext *ctx, CallExprNode *expr,
 	                                 Label *label_break, int returns)
 {
 	Node *arg = expr->argv;
-    
 	while(arg)
 	{
 		emitInstrForNode(ctx, arg, label_break);
 		arg = arg->next;
 	}
 
-	emitInstrForNode(ctx, expr->func, label_break);
+	int argc;
+	if (expr->func->kind == NODE_EXPR && ((ExprNode*) expr->func)->kind == EXPR_ARW) {
+		IndexSelectionExprNode *selection = (IndexSelectionExprNode*) expr->func;
+		Node *idx = selection->idx;
+		Node *set = selection->set;
+		emitInstrForNode(ctx, set, label_break);
+		emitInstrForNode(ctx, idx, label_break);
+		CodegenContext_EmitInstr(ctx, OPCODE_SELECT2, NULL, 0, 
+								 expr->func->offset, 
+								 expr->func->length);
+		argc = expr->argc+1;
+	} else {
+		emitInstrForNode(ctx, expr->func, label_break);
+		argc = expr->argc;
+	}
 
 	Operand ops[2];
-	ops[0] = (Operand) { .type = OPTP_INT, .as_int = expr->argc };
+	ops[0] = (Operand) { .type = OPTP_INT, .as_int = argc };
 	ops[1] = (Operand) { .type = OPTP_INT, .as_int = returns };
-	CodegenContext_EmitInstr(ctx, OPCODE_CALL, ops, 2, expr->base.base.offset, expr->base.base.length);
+	CodegenContext_EmitInstr(ctx, OPCODE_CALL, ops, 2, 
+							 expr->base.base.offset, 
+							 expr->base.base.length);
 }
 
 static void emitInstrForExprNode(CodegenContext *ctx, ExprNode *expr, 
@@ -394,6 +409,11 @@ static void emitInstrForExprNode(CodegenContext *ctx, ExprNode *expr,
 			return;
 		}
 
+		case EXPR_ARW:
+		CodegenContext_ReportErrorAndJump(ctx, 0, "Operator -> out of a function call");
+		UNREACHABLE;
+		return;
+
 		case EXPR_AND:
 		{
 			OperExprNode *oper = (OperExprNode*) expr;

src/lib/compiler/parse.c

@@ -52,6 +52,7 @@
 ** +--------------------------------------------------------------------------+
 */
 
+#include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
 #include <assert.h>
@@ -112,6 +113,7 @@ typedef enum {
 	TNQL,
 	TLEQ,
 	TGEQ,
+	TARW,
 
 } TokenKind;
 
@@ -331,6 +333,7 @@ static Token *tokenize(Source *src, BPAlloc *alloc, Error *error)
 				{ TCOMMA, 1, ","  },
 				{   TSMT, 1, "|"  },
 				{   TMOD, 1, "%"  },
+				{   TARW, 2, "->" },
 			};
 
 			_Bool found = 0;
@@ -1364,7 +1367,7 @@ static Node *parse_primary_expresion(Context *ctx)
 	return NULL;
 }
 
-static Node *makeIndexSelectionExprNode(Context *ctx, Node *set, Node *idx)
+static Node *makeIndexOrArrowSelectionExprNode(Context *ctx, bool arrow, Node *set, Node *idx)
 {
 	IndexSelectionExprNode *sel = BPAlloc_Malloc(ctx->alloc, sizeof(IndexSelectionExprNode));
 
@@ -1378,7 +1381,7 @@ static Node *makeIndexSelectionExprNode(Context *ctx, Node *set, Node *idx)
 	sel->base.base.next = NULL;
 	sel->base.base.offset = -1;
 	sel->base.base.length = -1;
-	sel->base.kind = EXPR_SELECT;
+	sel->base.kind = arrow ? EXPR_ARW : EXPR_SELECT;
 	sel->set = set;
 	sel->idx = idx;
 	return (Node*) sel;
@@ -1398,20 +1401,23 @@ static Node *parse_postfix_expression(Context *ctx)
 		switch(current(ctx))
 		{
 			case '.':
+			case TARW:
 			{
+				bool arrow = (current(ctx) == TARW);
+
 				next(ctx);
 
-				// We expect an identifier after the dot.
+				// We expect an identifier after the dot or arrow
 
 				if(done(ctx))
 				{
-					Error_Report(ctx->error, 0, "Source ended after dot of dot selection expression");
+					Error_Report(ctx->error, 0, "Source ended after dot or arrow");
 					return NULL;
 				}
 
 				if(current(ctx) != TIDENT)
 				{
-					Error_Report(ctx->error, 0, "Got unexpected token \"%.*s\" after fot of dot selection expression where an identifier was expected", ctx->token->length, ctx->src + ctx->token->offset);
+					Error_Report(ctx->error, 0, "Got unexpected token \"%.*s\" after dot or arrow, where an identifier was expected", ctx->token->length, ctx->src + ctx->token->offset);
 					return NULL;
 				}
 
@@ -1419,7 +1425,7 @@ static Node *parse_postfix_expression(Context *ctx)
 				if(idx == NULL)
 					return NULL;
 
-				Node *sel = makeIndexSelectionExprNode(ctx, node, idx);
+				Node *sel = makeIndexOrArrowSelectionExprNode(ctx, arrow, node, idx);
 				if(sel == NULL)
 					return NULL;
 
@@ -1446,7 +1452,7 @@ static Node *parse_postfix_expression(Context *ctx)
 					return NULL;
 				}
 
-				Node *sel = makeIndexSelectionExprNode(ctx, node, ls->itemc == 1 ? ls->items : (Node*) ls);
+				Node *sel = makeIndexOrArrowSelectionExprNode(ctx, false, node, ls->itemc == 1 ? ls->items : (Node*) ls);
 				if(sel == NULL)
 					return NULL;
 
@@ -1653,7 +1659,7 @@ static inline int precedenceof(Token *tok)
 		
 		case ',':
 		return 7;
-		
+
 		default:
 		return -100000000;
 	}
@@ -1723,7 +1729,6 @@ static Node *parse_expression_2(Context *ctx, Node *left_expr, int min_prec, _Bo
 				case '=': temp->base.kind = EXPR_ASS; break;
 				case '|': temp->base.kind = EXPR_SUMTYPE; break;
 				case ',': temp->base.kind = EXPR_PAIR; break;
-				
 				default:
 				UNREACHABLE;
 				break;

src/lib/runtime/runtime.c

@@ -978,12 +978,18 @@ static _Bool step(Runtime *runtime, Error *error)
 		}
 
 		case OPCODE_SELECT:
+		case OPCODE_SELECT2:
 		{
 			ASSERT(opc == 0);
 
-			if(runtime->frame->used < 2)
+			int to_be_popped = (opcode == OPCODE_SELECT) ? 2 : 1;
+
+			if(runtime->frame->used < to_be_popped)
 			{
-				Error_Report(error, 1, "Frame has not enough values on the stack to run SELECT instruction");
+				const char *name = "SELECT";
+				if (opcode == OPCODE_SELECT2)
+					name = "SELECT2";
+				Error_Report(error, 1, "Frame has not enough values on the stack to run %s instruction", name);
 				return 0;
 			}
 
@@ -992,7 +998,7 @@ static _Bool step(Runtime *runtime, Error *error)
 
 			ASSERT(col != NULL && key != NULL);
 
-			if(!Runtime_Pop(runtime, error, 2))
+			if(!Runtime_Pop(runtime, error, to_be_popped))
 				return 0;
 
 			ASSERT(error->occurred == 0);
@@ -1007,7 +1013,6 @@ static _Bool step(Runtime *runtime, Error *error)
 					Error_Free(&dummy);
 
 					val = Object_NewNone(runtime->heap, error);
-
 					if(val == NULL)
 						return 0;
 				}