added index selection

src/common/executable.c

@@ -59,6 +59,7 @@ static const InstrInfo instr_table[] = {
 	[OPCODE_POP]  = {"POP", 1, (OperandType[]) {OPTP_INT}},
 	[OPCODE_CALL] = {"CALL", 1, (OperandType[]) {OPTP_INT}},
 	[OPCODE_INSERT] = {"INSERT", 0, NULL},
+	[OPCODE_SELECT] = {"SELECT", 0, NULL},
 	[OPCODE_PUSHINT] = {"PUSHINT", 1, (OperandType[]) {OPTP_INT}},
 	[OPCODE_PUSHFLT] = {"PUSHFLT", 1, (OperandType[]) {OPTP_FLOAT}},
 	[OPCODE_PUSHSTR] = {"PUSHSTR", 1, (OperandType[]) {OPTP_STRING}},

src/common/executable.h

@@ -38,6 +38,7 @@ typedef enum {
 	OPCODE_POP,
 	OPCODE_CALL,
 	OPCODE_INSERT,
+	OPCODE_SELECT,
 	OPCODE_PUSHINT,
 	OPCODE_PUSHFLT,
 	OPCODE_PUSHSTR,

src/compiler/ASTi.h

@@ -40,6 +40,7 @@ typedef enum {
 	EXPR_FLOAT,
 	EXPR_STRING,
 	EXPR_IDENT,
+	EXPR_SELECT,
 } ExprKind;
 
 typedef struct Node Node;
@@ -104,6 +105,12 @@ typedef struct {
 	int      argc;
 } CallExprNode;
 
+typedef struct {
+	ExprNode base;
+	Node    *idx;
+	Node    *set;
+} IndexSelectionExprNode;
+
 typedef struct {
 	Node  base;
 	Node *condition;

src/compiler/compile.c

@@ -188,6 +188,19 @@ static _Bool emit_instr_for_node(ExeBuilder *exeb, Node *node, Error *error)
 							return ExeBuilder_Append(exeb, error, OPCODE_CALL, &op, 1, node->offset, node->length);
 						}
 
+						case EXPR_SELECT:
+						{
+							IndexSelectionExprNode *sel = (IndexSelectionExprNode*) expr;
+					
+							if(!emit_instr_for_node(exeb, sel->set, error))
+								return 0;
+
+							if(!emit_instr_for_node(exeb, sel->idx, error))
+								return 0;
+
+							return ExeBuilder_Append(exeb, error, OPCODE_SELECT, NULL, 0, node->offset, node->length);
+						}
+
 						case EXPR_NONE:
 						return ExeBuilder_Append(exeb, error, OPCODE_PUSHNNE, NULL, 0, node->offset, node->length);
 

src/compiler/parse.c

@@ -1160,6 +1160,44 @@ static Node *parse_postfix_expression(Context *ctx)
 		{
 			switch(current(ctx))
 				{
+					case '[':
+					{
+						Node *idx = parse_list_primary_expression(ctx);
+
+						if(idx == NULL)
+							return NULL;
+
+						ListExprNode *ls = (ListExprNode*) idx;
+
+						if(ls->itemc == 0)
+							{
+								Error_Report(ctx->error, 0, "Missing index in index selection expression");
+								return NULL;
+							}
+
+						IndexSelectionExprNode *sel;
+						{
+							sel = BPAlloc_Malloc(ctx->alloc, sizeof(IndexSelectionExprNode));
+
+							if(sel == NULL)
+								{
+									Error_Report(ctx->error, 1, "No memory");
+									return NULL;
+								}
+
+							sel->base.base.kind = NODE_EXPR;
+							sel->base.base.next = NULL;
+							sel->base.base.offset = node->offset;
+							sel->base.base.length = idx->offset + idx->length - node->offset;
+							sel->base.kind = EXPR_SELECT;
+							sel->set = node;
+							sel->idx = ls->itemc == 1 ? ls->items : (Node*) ls;
+						}
+
+						node = (Node*) sel;
+						break;
+					}
+
 					case '(':
 					{
 						int offset = current_token(ctx)->offset;

src/runtime/runtime.c

@@ -665,6 +665,34 @@ static _Bool step(Runtime *runtime, Error *error)
 				return 1;
 			}
 
+			case OPCODE_SELECT:
+			{
+				assert(opc == 0);
+
+				if(runtime->frame->used < 2)
+					{
+						Error_Report(error, 1, "Frame has not enough values on the stack to run SELECT instruction");
+						return NULL;
+					}
+
+				Object *col = Stack_Top(runtime->stack, -1);
+				Object *key = Stack_Top(runtime->stack,  0);
+
+				assert(col != NULL && key != NULL);
+
+				if(!Runtime_Pop(runtime, error, 2))
+					return 0;
+
+				Object *val = Object_Select(col, key, runtime->heap, error);
+
+				if(val == NULL)
+					return 0;
+
+				if(!Runtime_Push(runtime, error, val))
+					return 0;
+				return 1;
+			}
+
 			case OPCODE_PUSHINT:
 			{
 				assert(opc == 1);