1 files changed, 73 insertions, 6 deletions

diff --git a/modules/gdscript/gd_parser.cpp b/modules/gdscript/gd_parser.cpp
index 2829132d99..ef9e85a8c2 100644
--- a/modules/gdscript/gd_parser.cpp
+++ b/modules/gdscript/gd_parser.cpp
@@ -29,6 +29,7 @@
 #include "gd_parser.h"
 #include "print_string.h"
 #include "io/resource_loader.h"
+#include "os/file_access.h"
 /* TODO:
 
    *Property reduce constant expressions
@@ -224,12 +225,23 @@ GDParser::Node* GDParser::_parse_expression(Node *p_parent,bool p_static,bool p_
 			String path = tokenizer->get_token_constant();
 			if (!path.is_abs_path() && base_path!="")
 				path=base_path+"/"+path;
-            path = path.replace("///","//");
+			path = path.replace("///","//");
 
-			Ref<Resource> res = ResourceLoader::load(path);
-			if (!res.is_valid()) {
-				_set_error("Can't preload resource at path: "+path);
-				return NULL;
+			Ref<Resource> res;
+			if (!validating) {
+
+				//this can be too slow for just validating code
+				res = ResourceLoader::load(path);
+				if (!res.is_valid()) {
+					_set_error("Can't preload resource at path: "+path);
+					return NULL;
+				}
+			} else {
+
+				if (!FileAccess::exists(path)) {
+					_set_error("Can't preload resource at path: "+path);
+					return NULL;
+				}
 			}
 
 			tokenizer->advance();
@@ -244,6 +256,55 @@ GDParser::Node* GDParser::_parse_expression(Node *p_parent,bool p_static,bool p_
 			tokenizer->advance();
 
 			expr=constant;
+		} else if (tokenizer->get_token()==GDTokenizer::TK_PR_YIELD) {
+
+			//constant defined by tokenizer
+
+			tokenizer->advance();
+			if (tokenizer->get_token()!=GDTokenizer::TK_PARENTHESIS_OPEN) {
+				_set_error("Expected '(' after 'yield'");
+				return NULL;
+			}
+
+			tokenizer->advance();
+
+			OperatorNode *yield = alloc_node<OperatorNode>();
+			yield->op=OperatorNode::OP_YIELD;
+
+			if (tokenizer->get_token()==GDTokenizer::TK_PARENTHESIS_CLOSE) {
+				expr=yield;
+				tokenizer->advance();
+			} else {
+
+				Node *object = _parse_and_reduce_expression(p_parent,p_static);
+				if (!object)
+					return NULL;
+				yield->arguments.push_back(object);
+
+				if (tokenizer->get_token()!=GDTokenizer::TK_COMMA) {
+
+					_set_error("Expected ',' after first argument of 'yield'");
+					return NULL;
+				}
+
+				tokenizer->advance();
+
+				Node *signal = _parse_and_reduce_expression(p_parent,p_static);
+				if (!signal)
+					return NULL;
+				yield->arguments.push_back(signal);
+
+				if (tokenizer->get_token()!=GDTokenizer::TK_PARENTHESIS_CLOSE) {
+
+					_set_error("Expected ')' after second argument of 'yield'");
+					return NULL;
+				}
+
+				tokenizer->advance();
+
+				expr=yield;
+			}
+
 
 		} else if (tokenizer->get_token()==GDTokenizer::TK_SELF) {
 
@@ -1055,6 +1116,10 @@ GDParser::Node* GDParser::_reduce_expression(Node *p_node,bool p_to_const) {
 				}
 
 				return op; //don't reduce yet
+
+			} else if (op->op==OperatorNode::OP_YIELD) {
+				return op;
+
 			} else if (op->op==OperatorNode::OP_INDEX) {
 				//can reduce indices into constant arrays or dictionaries
 
@@ -2468,12 +2533,13 @@ Error GDParser::parse_bytecode(const Vector<uint8_t> &p_bytecode,const String& p
 }
 
 
-Error GDParser::parse(const String& p_code,const String& p_base_path) {
+Error GDParser::parse(const String& p_code,const String& p_base_path,bool p_just_validate) {
 
 
 	GDTokenizerText *tt = memnew( GDTokenizerText );
 	tt->set_code(p_code);
 
+	validating=p_just_validate;
 	tokenizer=tt;
 	Error ret = _parse(p_base_path);
 	memdelete(tt);
@@ -2498,6 +2564,7 @@ void GDParser::clear() {
 	head=NULL;
 	list=NULL;
 
+	validating=false;
 	error_set=false;
 	tab_level.clear();
 	tab_level.push_back(0);