infix functions

include/lang2/bytecode.h

@@ -51,6 +51,16 @@ enum l2_opcode {
 	 */
 	L2_OP_FUNC_CALL,
 
+	/*
+	 * Call an infix function
+	 * Pop <rhs>
+	 * Pop <func>
+	 * Pop <lhs>
+	 * Call <func>
+	 * (Before returning, the function will push a return value onto the stack)
+	 */
+	L2_OP_FUNC_CALL_INFIX,
+
 	/*
 	 * Jump relative; rjmp <count>
 	 * Jump <count> words forwards

include/lang2/gen/gen.h

@@ -51,5 +51,6 @@ void l2_gen_stack_frame_set_copy(struct l2_generator *gen, char *ident);
 void l2_gen_stack_frame_replace(struct l2_generator *gen, char **ident);
 void l2_gen_stack_frame_replace_copy(struct l2_generator *gen, char *ident);
 void l2_gen_func_call(struct l2_generator *gen, l2_word argc);
+void l2_gen_func_call_infix(struct l2_generator *gen);
 
 #endif

lib/gen/gen.c

@@ -221,3 +221,7 @@ void l2_gen_func_call(struct l2_generator *gen, l2_word argc) {
 	put(gen, L2_OP_FUNC_CALL);
 	put(gen, argc);
 }
+
+void l2_gen_func_call_infix(struct l2_generator *gen) {
+	put(gen, L2_OP_FUNC_CALL_INFIX);
+}

lib/parse/lex.c

@@ -98,6 +98,11 @@ static int peek_ch(struct l2_lexer *lexer) {
 	return ch;
 }
 
+static int peek_ch_n(struct l2_lexer *lexer, int n) {
+	int ch = l2_bufio_peek(&lexer->reader, n);
+	return ch;
+}
+
 static int read_ch(struct l2_lexer *lexer) {
 	int ch = l2_bufio_get(&lexer->reader);
 	lexer->ch += 1;
@@ -568,7 +573,9 @@ static void read_tok(struct l2_lexer *lexer, struct l2_token *tok) {
 		break;
 
 	default:
-		if (is_numeric(ch) || ch == '-') {
+		if (
+				is_numeric(ch) ||
+				(ch == '-' && is_numeric(peek_ch_n(lexer, 2)))) {
 			read_number(lexer, tok);
 			break;
 		}

lib/parse/parse.c

@@ -11,6 +11,23 @@ static int tok_is_end(struct l2_token *tok) {
 		kind == L2_TOK_EOL;
 }
 
+static int tok_is_infix(struct l2_token *tok) {
+	if (l2_token_get_kind(tok) != L2_TOK_IDENT) return 0;
+	char *str;
+	if (l2_token_is_small(tok)) {
+		str = tok->v.strbuf;
+	} else {
+		str = tok->v.str;
+	}
+
+	return
+			(str[0] == '$' && str[1] != '\0') ||
+			strcmp(str, "+") == 0 ||
+			strcmp(str, "-") == 0 ||
+			strcmp(str, "*") == 0 ||
+			strcmp(str, "/") == 0;
+}
+
 static int parse_expression(
 		struct l2_lexer *lexer, struct l2_generator *gen, struct l2_parse_error *err);
 
@@ -85,9 +102,8 @@ static int parse_function_literal_impl(
 	// '{' and EOL already skipped by parse_object_or_function_literal
 
 	// The arguments array will be at the top of the stack
-	char *ident = malloc(2);
-	ident[0] = '$'; ident[1] = '\0';
-	l2_gen_stack_frame_set(gen, &ident);
+	char *ident = "$";
+	l2_gen_stack_frame_set_copy(gen, ident);
 
 	int first = 1;
 	while (1) {
@@ -474,6 +490,19 @@ static int parse_expression(
 			return -1;
 		}
 
+		if (tok_is_infix(l2_lexer_peek(lexer, 1))) {
+			if (parse_arg_level_expression(lexer, gen, err) < 0) {
+				return -1;
+			}
+
+			if (parse_arg_level_expression(lexer, gen, err) < 0) {
+				return -1;
+			}
+
+
+			l2_gen_func_call_infix(gen);
+		}
+
 		if (!tok_is_end(l2_lexer_peek(lexer, 1))) {
 			if (parse_func_call_after_base(lexer, gen, err) < 0) {
 				return -1;

lib/vm/print.c

@@ -138,6 +138,10 @@ void l2_vm_print_op(l2_word *ops, size_t opcount, size_t *ptr) {
 		printf("FUNC_CALL %08x\n", ops[(*ptr)++]);
 		return;
 
+	case L2_OP_FUNC_CALL_INFIX:
+		printf("FUNC_CALL_INFIX\n");
+		return;
+
 	case L2_OP_RJMP:
 		printf("RJMP %08x\n", ops[(*ptr)++]);
 		return;

lib/vm/vm.c

@@ -319,7 +319,6 @@ void l2_vm_step(struct l2_vm *vm) {
 			struct l2_vm_value *func = &vm->values[func_id];
 
 			l2_word stack_base = vm->sptr;
-
 			enum l2_value_type typ = l2_vm_value_type(func);
 
 			// C functions are called differently from language functions
@@ -568,6 +567,56 @@ void l2_vm_step(struct l2_vm *vm) {
 		}
 		break;
 
+	case L2_OP_FUNC_CALL_INFIX:
+		{
+			l2_word rhs = vm->stack[--vm->sptr];
+			l2_word func_id = vm->stack[--vm->sptr];
+			l2_word lhs = vm->stack[--vm->sptr];
+
+			struct l2_vm_value *func = &vm->values[func_id];
+
+			l2_word stack_base = vm->sptr;
+			enum l2_value_type typ = l2_vm_value_type(func);
+
+			// C functions are called differently from language functions
+			if (typ == L2_VAL_TYPE_CFUNCTION) {
+				l2_word argv[] = { lhs, rhs };
+				vm->stack[vm->sptr++] = func->cfunc(vm, 2, argv);
+				break;
+			}
+
+			// Don't interpret a non-function as a function
+			if (typ != L2_VAL_TYPE_FUNCTION) {
+				vm->stack[vm->sptr++] = l2_vm_error(vm, "Attempt to call non-function");
+				break;
+			}
+
+			l2_word arr_id = alloc_val(vm);
+			vm->values[arr_id].flags = L2_VAL_TYPE_ARRAY;
+			vm->values[arr_id].array = malloc(
+					sizeof(struct l2_vm_array) + sizeof(l2_word) * 2);
+			struct l2_vm_array *arr = vm->values[arr_id].array;
+			arr->len = 2;
+			arr->size = 2;
+			arr->data[0] = lhs;
+			arr->data[1] = rhs;
+
+			vm->stack[vm->sptr++] = arr_id;
+
+			l2_word ns_id = alloc_val(vm);
+			func = &vm->values[func_id]; // func might be stale after alloc
+			vm->values[ns_id].extra.ns_parent = func->func.ns;
+			vm->values[ns_id].ns = NULL;
+			vm->values[ns_id].flags = L2_VAL_TYPE_NAMESPACE;
+			vm->fstack[vm->fsptr].ns = ns_id;
+			vm->fstack[vm->fsptr].retptr = vm->iptr;
+			vm->fstack[vm->fsptr].sptr = stack_base;
+			vm->fsptr += 1;
+
+			vm->iptr = func->func.pos;
+		}
+		break;
+
 	case L2_OP_HALT:
 		vm->halted = 1;
 		break;