godot/modules/gdscript/gd_parser.cpp

/*************************************************************************/
/*  gd_parser.cpp                                                        */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                    http://www.godotengine.org                         */
/*************************************************************************/
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                 */
/*                                                                       */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the       */
/* "Software"), to deal in the Software without restriction, including   */
/* without limitation the rights to use, copy, modify, merge, publish,   */
/* distribute, sublicense, and/or sell copies of the Software, and to    */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions:                                             */
/*                                                                       */
/* The above copyright notice and this permission notice shall be        */
/* included in all copies or substantial portions of the Software.       */
/*                                                                       */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
/*************************************************************************/
#include "gd_parser.h"
#include "print_string.h"
#include "io/resource_loader.h"
/* TODO:

   *Property reduce constant expressions
   *Implement missing operators in variant?
   *constructor
 */

/*
 todo:
 fix post ++,--
 make sure ++,-- don't work on constant expressions
 seems passing parent node as param is not needed
 */

template<class T>
T* GDParser::alloc_node() {

	T *t = memnew( T);

	t->next=list;
	list=t;

	if (!head)
		head=t;

	t->line=tokenizer.get_token_line();
	t->column=tokenizer.get_token_column();
	return t;

}

bool GDParser::_end_statement() {

	if (tokenizer.get_token()==GDTokenizer::TK_SEMICOLON) {
		tokenizer.advance();
		return true; //handle next
	} else if (tokenizer.get_token()==GDTokenizer::TK_NEWLINE || tokenizer.get_token()==GDTokenizer::TK_EOF) {
		return true; //will be handled properly
	}

	return false;
}

bool GDParser::_enter_indent_block(BlockNode* p_block) {


	if (tokenizer.get_token()!=GDTokenizer::TK_COLON) {

		_set_error("':' expected at end of line.");
		return false;
	}
	tokenizer.advance();

	if (tokenizer.get_token()!=GDTokenizer::TK_NEWLINE) {

		_set_error("newline expected after ':'.");
		return false;
	}

	while(true) {

		if (tokenizer.get_token()!=GDTokenizer::TK_NEWLINE) {
			return false; //wtf
		} else if (tokenizer.get_token(1)!=GDTokenizer::TK_NEWLINE) {

			int indent = tokenizer.get_token_line_indent();
			int current = tab_level.back()->get();
			if (indent<=current)
				return false;

			tab_level.push_back(indent);
			tokenizer.advance();
			return true;

		} else if (p_block) {

			NewLineNode *nl = alloc_node<NewLineNode>();
			nl->line=tokenizer.get_token_line();
			p_block->statements.push_back(nl);

		}

		tokenizer.advance(); // go to next newline
	}
}

bool GDParser::_parse_arguments(Node* p_parent,Vector<Node*>& p_args,bool p_static) {

	if (tokenizer.get_token()==GDTokenizer::TK_PARENTHESIS_CLOSE) {
		tokenizer.advance();
	} else {

		while(true) {


			Node*arg  = _parse_expression(p_parent,p_static);
			if (!arg)
				return false;

			p_args.push_back(arg);

			if (tokenizer.get_token()==GDTokenizer::TK_PARENTHESIS_CLOSE) {
				tokenizer.advance();
				break;

			} else if (tokenizer.get_token()==GDTokenizer::TK_COMMA) {

				if (tokenizer.get_token(1)==GDTokenizer::TK_PARENTHESIS_CLOSE) {

					_set_error("Expression expected");
					return false;
				}

				tokenizer.advance();
			} else {
				// something is broken
				_set_error("Expected ',' or ')'");
				return false;
			}

		}
	}

	return true;

}



GDParser::Node* GDParser::_parse_expression(Node *p_parent,bool p_static,bool p_allow_assign) {

//	Vector<Node*> expressions;
//	Vector<OperatorNode::Operator> operators;

	Vector<Expression> expression;

	Node *expr=NULL;

	while(true) {


		/*****************/
		/* Parse Operand */
		/*****************/

		if (tokenizer.get_token()==GDTokenizer::TK_PARENTHESIS_OPEN) {
			//subexpression ()
			tokenizer.advance();
			Node* subexpr = _parse_expression(p_parent,p_static);
			if (!subexpr)
				return NULL;

			if (tokenizer.get_token()!=GDTokenizer::TK_PARENTHESIS_CLOSE) {

				_set_error("Expected ')' in expression");
				return NULL;
			}

			tokenizer.advance();
			expr=subexpr;

		} else if (tokenizer.get_token()==GDTokenizer::TK_CONSTANT) {

			//constant defined by tokenizer
			ConstantNode *constant = alloc_node<ConstantNode>();
			constant->value=tokenizer.get_token_constant();			
			tokenizer.advance();
			expr=constant;
		} else if (tokenizer.get_token()==GDTokenizer::TK_PR_PRELOAD) {

			//constant defined by tokenizer
			tokenizer.advance();
			if (tokenizer.get_token()!=GDTokenizer::TK_PARENTHESIS_OPEN) {
				_set_error("Expected '(' after 'preload'");
				return NULL;
			}
			tokenizer.advance();
			if (tokenizer.get_token()!=GDTokenizer::TK_CONSTANT || tokenizer.get_token_constant().get_type()!=Variant::STRING) {
				_set_error("Expected string constant as 'preload' argument.");
				return NULL;
			}


			String path = tokenizer.get_token_constant();
			if (!path.is_abs_path() && base_path!="")
				path=base_path+"/"+path;

			Ref<Resource> res = ResourceLoader::load(path);
			if (!res.is_valid()) {
				_set_error("Can't preload resource at path: "+path);
				return NULL;
			}

			tokenizer.advance();

			if (tokenizer.get_token()!=GDTokenizer::TK_PARENTHESIS_CLOSE) {
				_set_error("Expected ')' after 'preload' path");
				return NULL;
			}

			ConstantNode *constant = alloc_node<ConstantNode>();
			constant->value=res;
			tokenizer.advance();

			expr=constant;

		} else if (tokenizer.get_token()==GDTokenizer::TK_SELF) {

			if (p_static) {
				_set_error("'self'' not allowed in static function or constant expression");
				return NULL;
			}
			//constant defined by tokenizer
			SelfNode *self = alloc_node<SelfNode>();
			tokenizer.advance();
			expr=self;
		} else if (tokenizer.get_token()==GDTokenizer::TK_BUILT_IN_TYPE && tokenizer.get_token(1)==GDTokenizer::TK_PERIOD) {

			Variant::Type bi_type = tokenizer.get_token_type();
			tokenizer.advance(2);
			if (tokenizer.get_token()!=GDTokenizer::TK_IDENTIFIER) {

				_set_error("Built-in type constant expected after '.'");
				return NULL;
			}
			StringName identifier = tokenizer.get_token_identifier();
			if (!Variant::has_numeric_constant(bi_type,identifier)) {

				_set_error("Static constant  '"+identifier.operator String()+"' not present in built-in type "+Variant::get_type_name(bi_type)+".");
				return NULL;
			}

			ConstantNode *cn = alloc_node<ConstantNode>();
			cn->value=Variant::get_numeric_constant_value(bi_type,identifier);
			expr=cn;
			tokenizer.advance();

		} else if (tokenizer.get_token(1)==GDTokenizer::TK_PARENTHESIS_OPEN && (tokenizer.get_token()==GDTokenizer::TK_BUILT_IN_TYPE || tokenizer.get_token()==GDTokenizer::TK_IDENTIFIER || tokenizer.get_token()==GDTokenizer::TK_BUILT_IN_FUNC)) {
			//function or constructor

			OperatorNode *op = alloc_node<OperatorNode>();
			op->op=OperatorNode::OP_CALL;

			if (tokenizer.get_token()==GDTokenizer::TK_BUILT_IN_TYPE) {

				TypeNode *tn = alloc_node<TypeNode>();
				tn->vtype=tokenizer.get_token_type();
				op->arguments.push_back(tn);
			} else if (tokenizer.get_token()==GDTokenizer::TK_BUILT_IN_FUNC) {

				BuiltInFunctionNode *bn = alloc_node<BuiltInFunctionNode>();
				bn->function=tokenizer.get_token_built_in_func();
				op->arguments.push_back(bn);
			} else {

				SelfNode *self = alloc_node<SelfNode>();
				op->arguments.push_back(self);

				IdentifierNode* id = alloc_node<IdentifierNode>();
				id->name=tokenizer.get_token_identifier();
				op->arguments.push_back(id);
			}

			tokenizer.advance(2);
			if (!_parse_arguments(op,op->arguments,p_static))
				return NULL;

			expr=op;

		} else if (tokenizer.get_token()==GDTokenizer::TK_IDENTIFIER) {
			//identifier (reference)

			IdentifierNode *id = alloc_node<IdentifierNode>();
			id->name=tokenizer.get_token_identifier();
			tokenizer.advance();
			expr=id;

		} else if (/*tokenizer.get_token()==GDTokenizer::TK_OP_ADD ||*/ tokenizer.get_token()==GDTokenizer::TK_OP_SUB || tokenizer.get_token()==GDTokenizer::TK_OP_NOT || tokenizer.get_token()==GDTokenizer::TK_OP_BIT_INVERT) {

			//single prefix operators like !expr -expr ++expr --expr
			OperatorNode *op = alloc_node<OperatorNode>();

			Expression e;
			e.is_op=true;

			switch(tokenizer.get_token()) {
				case GDTokenizer::TK_OP_SUB: e.op=OperatorNode::OP_NEG; break;
				case GDTokenizer::TK_OP_NOT: e.op=OperatorNode::OP_NOT; break;
				case GDTokenizer::TK_OP_BIT_INVERT: e.op=OperatorNode::OP_BIT_INVERT;; break;
				default: {}
			}


			tokenizer.advance();

			if (e.op!=OperatorNode::OP_NOT && tokenizer.get_token()==GDTokenizer::TK_OP_NOT) {
				_set_error("Misplaced 'not'.");
				return NULL;
			}

			expression.push_back(e);
			continue; //only exception, must continue...

			/*
			Node *subexpr=_parse_expression(op,p_static);
			if (!subexpr)
				return NULL;
			op->arguments.push_back(subexpr);
			expr=op;*/

		} else if (tokenizer.get_token()==GDTokenizer::TK_BRACKET_OPEN) {
			// array
			tokenizer.advance();

			ArrayNode *arr = alloc_node<ArrayNode>();
			bool expecting_comma=false;

			while(true) {

				if (tokenizer.get_token()==GDTokenizer::TK_EOF) {

					_set_error("Unterminated array");
					return NULL;

				} else if (tokenizer.get_token()==GDTokenizer::TK_BRACKET_CLOSE) {
					tokenizer.advance();
					break;
				} else if (tokenizer.get_token()==GDTokenizer::TK_NEWLINE) {

					tokenizer.advance(); //ignore newline
				} else if (tokenizer.get_token()==GDTokenizer::TK_COMMA) {
					if (!expecting_comma) {
						_set_error("expression or ']' expected");
						return NULL;
					}

					expecting_comma=false;
					tokenizer.advance(); //ignore newline
				} else {
					//parse expression
					if (expecting_comma) {
						_set_error("',' or ']' expected");
						return NULL;
					}
					Node *n = _parse_expression(arr,p_static);
					if (!n)
						return NULL;
					arr->elements.push_back(n);
					expecting_comma=true;
				}
			}

			expr=arr;
		} else if (tokenizer.get_token()==GDTokenizer::TK_CURLY_BRACKET_OPEN) {
			// array
			tokenizer.advance();

			DictionaryNode *dict = alloc_node<DictionaryNode>();

			enum DictExpect {

				DICT_EXPECT_KEY,
				DICT_EXPECT_COLON,
				DICT_EXPECT_VALUE,
				DICT_EXPECT_COMMA

			};

			Node *key=NULL;

			DictExpect expecting=DICT_EXPECT_KEY;

			while(true) {

				if (tokenizer.get_token()==GDTokenizer::TK_EOF) {

					_set_error("Unterminated dictionary");
					return NULL;

				} else if (tokenizer.get_token()==GDTokenizer::TK_CURLY_BRACKET_CLOSE) {

					if (expecting==DICT_EXPECT_COLON) {
						_set_error("':' expected");
						return NULL;
					}
					if (expecting==DICT_EXPECT_VALUE) {
						_set_error("value expected");
						return NULL;
					}
					tokenizer.advance();
					break;
				} else if (tokenizer.get_token()==GDTokenizer::TK_NEWLINE) {

					tokenizer.advance(); //ignore newline
				} else if (tokenizer.get_token()==GDTokenizer::TK_COMMA) {

					if (expecting==DICT_EXPECT_KEY) {
						_set_error("key or '}' expected");
						return NULL;
					}
					if (expecting==DICT_EXPECT_VALUE) {
						_set_error("value expected");
						return NULL;
					}
					if (expecting==DICT_EXPECT_COLON) {
						_set_error("':' expected");
						return NULL;
					}

					expecting=DICT_EXPECT_KEY;
					tokenizer.advance(); //ignore newline

				} else if (tokenizer.get_token()==GDTokenizer::TK_COLON) {

					if (expecting==DICT_EXPECT_KEY) {
						_set_error("key or '}' expected");
						return NULL;
					}
					if (expecting==DICT_EXPECT_VALUE) {
						_set_error("value expected");
						return NULL;
					}
					if (expecting==DICT_EXPECT_COMMA) {
						_set_error("',' or '}' expected");
						return NULL;
					}

					expecting=DICT_EXPECT_VALUE;
					tokenizer.advance(); //ignore newline
				} else {

					if (expecting==DICT_EXPECT_COMMA) {
						_set_error("',' or '}' expected");
						return NULL;
					}
					if (expecting==DICT_EXPECT_COLON) {
						_set_error("':' expected");
						return NULL;
					}

					if (expecting==DICT_EXPECT_KEY) {

						if (tokenizer.get_token()==GDTokenizer::TK_IDENTIFIER && tokenizer.get_token(1)==GDTokenizer::TK_OP_ASSIGN) {
							//lua style identifier, easier to write
							ConstantNode *cn = alloc_node<ConstantNode>();
							cn->value = tokenizer.get_token_identifier();
							key = cn;
							tokenizer.advance(2);
							expecting=DICT_EXPECT_VALUE;
						} else {
							//python/js style more flexible
							key = _parse_expression(dict,p_static);
							if (!key)
								return NULL;
							expecting=DICT_EXPECT_COLON;
						}
					}

					if (expecting==DICT_EXPECT_VALUE) {
						Node *value = _parse_expression(dict,p_static);
						if (!value)
							return NULL;
						expecting=DICT_EXPECT_COMMA;

						DictionaryNode::Pair pair;
						pair.key=key;
						pair.value=value;
						dict->elements.push_back(pair);
						key=NULL;

					}

				}
			}

			expr=dict;

		} else if (tokenizer.get_token()==GDTokenizer::TK_PERIOD && tokenizer.get_token(1)==GDTokenizer::TK_IDENTIFIER && tokenizer.get_token(2)==GDTokenizer::TK_PARENTHESIS_OPEN) {
			// parent call

			tokenizer.advance(); //goto identifier
			OperatorNode *op = alloc_node<OperatorNode>();
			op->op=OperatorNode::OP_PARENT_CALL;


			/*SelfNode *self = alloc_node<SelfNode>();
			op->arguments.push_back(self);
			forbidden for now */

			IdentifierNode* id = alloc_node<IdentifierNode>();
			id->name=tokenizer.get_token_identifier();
			op->arguments.push_back(id);

			tokenizer.advance(2);
			if (!_parse_arguments(op,op->arguments,p_static))
				return NULL;

			expr=op;

		} else {

			//find list [ or find dictionary {

			print_line("found bug?");

			_set_error("Error parsing expression, misplaced: "+String(tokenizer.get_token_name(tokenizer.get_token())));
			return NULL;		//nothing
		}

		if (!expr) {
			ERR_EXPLAIN("GDParser bug, couldn't figure out what expression is..");
			ERR_FAIL_COND_V(!expr,NULL);
		}


		/******************/
		/* Parse Indexing */
		/******************/


		while (true) {

			//expressions can be indexed any number of times

			if (tokenizer.get_token()==GDTokenizer::TK_PERIOD) {

				//indexing using "."

				if (tokenizer.get_token(1)!=GDTokenizer::TK_IDENTIFIER && tokenizer.get_token(1)!=GDTokenizer::TK_BUILT_IN_FUNC ) {
					_set_error("Expected identifier as member");
					return NULL;
				} else if (tokenizer.get_token(2)==GDTokenizer::TK_PARENTHESIS_OPEN) {
					//call!!
					OperatorNode * op = alloc_node<OperatorNode>();
					op->op=OperatorNode::OP_CALL;

					IdentifierNode * id = alloc_node<IdentifierNode>();
					if (tokenizer.get_token(1)==GDTokenizer::TK_BUILT_IN_FUNC ) {
						//small hack so built in funcs don't obfuscate methods

						id->name=GDFunctions::get_func_name(tokenizer.get_token_built_in_func(1));
					} else {
						id->name=tokenizer.get_token_identifier(1);
					}

					op->arguments.push_back(expr); // call what
					op->arguments.push_back(id); // call func
					//get arguments
					tokenizer.advance(3);
					if (!_parse_arguments(op,op->arguments,p_static))
						return NULL;
					expr=op;

				} else {
					//simple indexing!
					OperatorNode * op = alloc_node<OperatorNode>();
					op->op=OperatorNode::OP_INDEX_NAMED;

					IdentifierNode * id = alloc_node<IdentifierNode>();
					id->name=tokenizer.get_token_identifier(1);

					op->arguments.push_back(expr);
					op->arguments.push_back(id);

					expr=op;

					tokenizer.advance(2);
				}

			} else if (tokenizer.get_token()==GDTokenizer::TK_BRACKET_OPEN) {
				//indexing using "[]"
				OperatorNode * op = alloc_node<OperatorNode>();
				op->op=OperatorNode::OP_INDEX;

				tokenizer.advance(1);

				Node *subexpr = _parse_expression(op,p_static);
				if (!subexpr) {
					return NULL;
				}

				if (tokenizer.get_token()!=GDTokenizer::TK_BRACKET_CLOSE) {
					_set_error("Expected ']'");
					return NULL;
				}

				op->arguments.push_back(expr);
				op->arguments.push_back(subexpr);
				tokenizer.advance(1);
				expr=op;

			} else
				break;
		}

		/******************/
		/* Parse Operator */
		/******************/


		Expression e;
		e.is_op=false;
		e.node=expr;
		expression.push_back(e);

		// determine which operator is next

		OperatorNode::Operator op;
		bool valid=true;

//assign, if allowed is only alowed on the first operator
#define _VALIDATE_ASSIGN if (!p_allow_assign) { _set_error("Unexpected assign."); return NULL; } p_allow_assign=false;
		switch(tokenizer.get_token()) { //see operator

			case GDTokenizer::TK_OP_IN: op=OperatorNode::OP_IN; break;
			case GDTokenizer::TK_OP_EQUAL: op=OperatorNode::OP_EQUAL ; break;
			case GDTokenizer::TK_OP_NOT_EQUAL: op=OperatorNode::OP_NOT_EQUAL ; break;
			case GDTokenizer::TK_OP_LESS: op=OperatorNode::OP_LESS ; break;
			case GDTokenizer::TK_OP_LESS_EQUAL: op=OperatorNode::OP_LESS_EQUAL ; break;
			case GDTokenizer::TK_OP_GREATER: op=OperatorNode::OP_GREATER ; break;
			case GDTokenizer::TK_OP_GREATER_EQUAL: op=OperatorNode::OP_GREATER_EQUAL ; break;
			case GDTokenizer::TK_OP_AND: op=OperatorNode::OP_AND ; break;
			case GDTokenizer::TK_OP_OR: op=OperatorNode::OP_OR ; break;
			case GDTokenizer::TK_OP_ADD: op=OperatorNode::OP_ADD ; break;
			case GDTokenizer::TK_OP_SUB: op=OperatorNode::OP_SUB ; break;
			case GDTokenizer::TK_OP_MUL: op=OperatorNode::OP_MUL ; break;
			case GDTokenizer::TK_OP_DIV: op=OperatorNode::OP_DIV ; break;
			case GDTokenizer::TK_OP_MOD: op=OperatorNode::OP_MOD ; break;
			//case GDTokenizer::TK_OP_NEG: op=OperatorNode::OP_NEG ; break;
			case GDTokenizer::TK_OP_SHIFT_LEFT: op=OperatorNode::OP_SHIFT_LEFT ; break;
			case GDTokenizer::TK_OP_SHIFT_RIGHT: op=OperatorNode::OP_SHIFT_RIGHT ; break;
			case GDTokenizer::TK_OP_ASSIGN: _VALIDATE_ASSIGN op=OperatorNode::OP_ASSIGN ; break;
			case GDTokenizer::TK_OP_ASSIGN_ADD: _VALIDATE_ASSIGN  op=OperatorNode::OP_ASSIGN_ADD ; break;
			case GDTokenizer::TK_OP_ASSIGN_SUB: _VALIDATE_ASSIGN op=OperatorNode::OP_ASSIGN_SUB ; break;
			case GDTokenizer::TK_OP_ASSIGN_MUL: _VALIDATE_ASSIGN op=OperatorNode::OP_ASSIGN_MUL ; break;
			case GDTokenizer::TK_OP_ASSIGN_DIV: _VALIDATE_ASSIGN op=OperatorNode::OP_ASSIGN_DIV ; break;
			case GDTokenizer::TK_OP_ASSIGN_MOD: _VALIDATE_ASSIGN op=OperatorNode::OP_ASSIGN_MOD ; break;
			case GDTokenizer::TK_OP_ASSIGN_SHIFT_LEFT: _VALIDATE_ASSIGN op=OperatorNode::OP_ASSIGN_SHIFT_LEFT; ; break;
			case GDTokenizer::TK_OP_ASSIGN_SHIFT_RIGHT: _VALIDATE_ASSIGN op=OperatorNode::OP_ASSIGN_SHIFT_RIGHT; ; break;
			case GDTokenizer::TK_OP_ASSIGN_BIT_AND: _VALIDATE_ASSIGN op=OperatorNode::OP_ASSIGN_BIT_AND ; break;
			case GDTokenizer::TK_OP_ASSIGN_BIT_OR: _VALIDATE_ASSIGN op=OperatorNode::OP_ASSIGN_BIT_OR ; break;
			case GDTokenizer::TK_OP_ASSIGN_BIT_XOR: _VALIDATE_ASSIGN op=OperatorNode::OP_ASSIGN_BIT_XOR ; break;
			case GDTokenizer::TK_OP_BIT_AND: op=OperatorNode::OP_BIT_AND ; break;
			case GDTokenizer::TK_OP_BIT_OR: op=OperatorNode::OP_BIT_OR ; break;
			case GDTokenizer::TK_OP_BIT_XOR: op=OperatorNode::OP_BIT_XOR ; break;
			case GDTokenizer::TK_PR_EXTENDS: op=OperatorNode::OP_EXTENDS; break;
			default: valid=false; break;
		}

		if (valid) {			
			e.is_op=true;
			e.op=op;
			expression.push_back(e);
			tokenizer.advance();
		} else {
			break;
		}

	}

	/* Reduce the set set of expressions and place them in an operator tree, respecting precedence */


	while(expression.size()>1) {

		int next_op=-1;
		int min_priority=0xFFFFF;
		bool is_unary=false;

		for(int i=0;i<expression.size();i++) {



			if (!expression[i].is_op) {

				continue;
			}

			int priority;

			bool unary=false;

			switch(expression[i].op) {

				case OperatorNode::OP_EXTENDS: priority=-1; break; //before anything

				case OperatorNode::OP_BIT_INVERT: priority=0; unary=true; break;
				case OperatorNode::OP_NEG: priority=1; unary=true; break;

				case OperatorNode::OP_MUL: priority=2; break;
				case OperatorNode::OP_DIV: priority=2; break;
				case OperatorNode::OP_MOD: priority=2; break;

				case OperatorNode::OP_ADD: priority=3; break;
				case OperatorNode::OP_SUB: priority=3; break;

				case OperatorNode::OP_SHIFT_LEFT: priority=4; break;
				case OperatorNode::OP_SHIFT_RIGHT: priority=4; break;

				case OperatorNode::OP_BIT_AND: priority=5; break;
				case OperatorNode::OP_BIT_XOR: priority=6; break;
				case OperatorNode::OP_BIT_OR: priority=7; break;

				case OperatorNode::OP_LESS: priority=8; break;
				case OperatorNode::OP_LESS_EQUAL: priority=8; break;
				case OperatorNode::OP_GREATER: priority=8; break;
				case OperatorNode::OP_GREATER_EQUAL: priority=8; break;

				case OperatorNode::OP_EQUAL: priority=8; break;
				case OperatorNode::OP_NOT_EQUAL: priority=8; break;

				case OperatorNode::OP_IN: priority=10; break;

				case OperatorNode::OP_NOT: priority=11; unary=true; break;
				case OperatorNode::OP_AND: priority=12; break;
				case OperatorNode::OP_OR: priority=13; break;

				// ?: = 10

				case OperatorNode::OP_ASSIGN: priority=14; break;
				case OperatorNode::OP_ASSIGN_ADD: priority=14; break;
				case OperatorNode::OP_ASSIGN_SUB: priority=14; break;
				case OperatorNode::OP_ASSIGN_MUL: priority=14; break;
				case OperatorNode::OP_ASSIGN_DIV: priority=14; break;
				case OperatorNode::OP_ASSIGN_MOD: priority=14; break;
				case OperatorNode::OP_ASSIGN_SHIFT_LEFT: priority=14; break;
				case OperatorNode::OP_ASSIGN_SHIFT_RIGHT: priority=14; break;
				case OperatorNode::OP_ASSIGN_BIT_AND: priority=14; break;
				case OperatorNode::OP_ASSIGN_BIT_OR: priority=14; break;
				case OperatorNode::OP_ASSIGN_BIT_XOR: priority=14; break;


				default: {
					_set_error("GDParser bug, invalid operator in expression: "+itos(expression[i].op));
					return NULL;
				}

			}

			if (priority<min_priority) {
				// < is used for left to right (default)
				// <= is used for right to left
				next_op=i;
				min_priority=priority;
				is_unary=unary;
			}

		}


		if (next_op==-1) {


			_set_error("Yet another parser bug....");
			ERR_FAIL_COND_V(next_op==-1,NULL);
		}


		// OK! create operator..
		if (is_unary) {

			int expr_pos=next_op;
			while(expression[expr_pos].is_op) {

				expr_pos++;
				if (expr_pos==expression.size()) {
					//can happen..
					_set_error("Unexpected end of expression..");
					return NULL;
				}
			}

			//consecutively do unary opeators
			for(int i=expr_pos-1;i>=next_op;i--) {

				OperatorNode *op = alloc_node<OperatorNode>();
				op->op=expression[i].op;
				op->arguments.push_back(expression[i+1].node);
				expression[i].is_op=false;
				expression[i].node=op;
				expression.remove(i+1);
			}


		} else {

			if (next_op <1 || next_op>=(expression.size()-1)) {
				_set_error("Parser bug..");
				ERR_FAIL_V(NULL);
			}

			OperatorNode *op = alloc_node<OperatorNode>();
			op->op=expression[next_op].op;

			if (expression[next_op-1].is_op) {

				_set_error("Parser bug..");
				ERR_FAIL_V(NULL);
			}

			if (expression[next_op+1].is_op) {
				// this is not invalid and can really appear
				// but it becomes invalid anyway because no binary op
				// can be followed by an unary op in a valid combination,
				// due to how precedence works, unaries will always dissapear first

				_set_error("Parser bug..");

			}


			op->arguments.push_back(expression[next_op-1].node); //expression goes as left
			op->arguments.push_back(expression[next_op+1].node); //next expression goes as right

			//replace all 3 nodes by this operator and make it an expression
			expression[next_op-1].node=op;
			expression.remove(next_op);
			expression.remove(next_op);
		}

	}

	return expression[0].node;

}


GDParser::Node* GDParser::_reduce_expression(Node *p_node,bool p_to_const) {

	switch(p_node->type) {

		case Node::TYPE_BUILT_IN_FUNCTION: {
			//many may probably be optimizable
			return p_node;
		} break;
		case Node::TYPE_ARRAY: {

			ArrayNode *an = static_cast<ArrayNode*>(p_node);
			bool all_constants=true;

			for(int i=0;i<an->elements.size();i++) {

				an->elements[i]=_reduce_expression(an->elements[i],p_to_const);
				if (an->elements[i]->type!=Node::TYPE_CONSTANT)
					all_constants=false;
			}

			if (all_constants && p_to_const) {
				//reduce constant array expression

				ConstantNode *cn = alloc_node<ConstantNode>();
				Array arr(!p_to_const);
				arr.resize(an->elements.size());
				for(int i=0;i<an->elements.size();i++) {
					ConstantNode *acn = static_cast<ConstantNode*>(an->elements[i]);
					arr[i]=acn->value;

				}
				cn->value=arr;
				return cn;
			}

			return an;

		} break;
		case Node::TYPE_DICTIONARY: {

			DictionaryNode *dn = static_cast<DictionaryNode*>(p_node);
			bool all_constants=true;

			for(int i=0;i<dn->elements.size();i++) {

				dn->elements[i].key=_reduce_expression(dn->elements[i].key,p_to_const);
				if (dn->elements[i].key->type!=Node::TYPE_CONSTANT)
					all_constants=false;
				dn->elements[i].value=_reduce_expression(dn->elements[i].value,p_to_const);
				if (dn->elements[i].value->type!=Node::TYPE_CONSTANT)
					all_constants=false;

			}

			if (all_constants && p_to_const) {
				//reduce constant array expression

				ConstantNode *cn = alloc_node<ConstantNode>();
				Dictionary dict(!p_to_const);
				for(int i=0;i<dn->elements.size();i++) {
					ConstantNode *key_c = static_cast<ConstantNode*>(dn->elements[i].key);
					ConstantNode *value_c = static_cast<ConstantNode*>(dn->elements[i].value);

					dict[key_c->value]=value_c->value;

				}
				cn->value=dict;
				return cn;
			}

			return dn;


		} break;
		case Node::TYPE_OPERATOR: {

			OperatorNode *op=static_cast<OperatorNode*>(p_node);

			bool all_constants=true;
			int last_not_constant=-1;

			for(int i=0;i<op->arguments.size();i++) {

				op->arguments[i]=_reduce_expression(op->arguments[i],p_to_const);
				if (op->arguments[i]->type!=Node::TYPE_CONSTANT) {
					all_constants=false;
					last_not_constant=i;
				}
			}

			if (op->op==OperatorNode::OP_EXTENDS) {
				//nothing much
				return op;

			} if (op->op==OperatorNode::OP_PARENT_CALL) {
				//nothing much
				return op;

			} else if (op->op==OperatorNode::OP_CALL) {
				//can reduce base type constructors
				if ((op->arguments[0]->type==Node::TYPE_TYPE || (op->arguments[0]->type==Node::TYPE_BUILT_IN_FUNCTION && GDFunctions::is_deterministic( static_cast<BuiltInFunctionNode*>(op->arguments[0])->function))) && last_not_constant==0) {

					//native type constructor or intrinsic function
					const Variant **vptr=NULL;
					Vector<Variant*> ptrs;
					if (op->arguments.size()>1) {

						ptrs.resize(op->arguments.size()-1);
						for(int i=0;i<ptrs.size();i++) {


							ConstantNode *cn = static_cast<ConstantNode*>(op->arguments[i+1]);
							ptrs[i]=&cn->value;
						}

						vptr=(const Variant**)&ptrs[0];


					}

					Variant::CallError ce;
					Variant v;

					if (op->arguments[0]->type==Node::TYPE_TYPE) {
						TypeNode *tn = static_cast<TypeNode*>(op->arguments[0]);
						v = Variant::construct(tn->vtype,vptr,ptrs.size(),ce);

					} else {
						GDFunctions::Function func = static_cast<BuiltInFunctionNode*>(op->arguments[0])->function;
						GDFunctions::call(func,vptr,ptrs.size(),v,ce);
					}


					if (ce.error!=Variant::CallError::CALL_OK) {

						String errwhere;
						if (op->arguments[0]->type==Node::TYPE_TYPE) {
							TypeNode *tn = static_cast<TypeNode*>(op->arguments[0]);
							errwhere="'"+Variant::get_type_name(tn->vtype)+"'' constructor";

						} else {
							GDFunctions::Function func = static_cast<BuiltInFunctionNode*>(op->arguments[0])->function;
							errwhere=String("'")+GDFunctions::get_func_name(func)+"'' intrinsic function";

						}

						switch(ce.error) {

							case Variant::CallError::CALL_ERROR_INVALID_ARGUMENT: {

								_set_error("Invalid argument (#"+itos(ce.argument+1)+") for "+errwhere+".");

							} break;
							case Variant::CallError::CALL_ERROR_TOO_MANY_ARGUMENTS: {

								_set_error("Too many arguments for "+errwhere+".");
							} break;
							case Variant::CallError::CALL_ERROR_TOO_FEW_ARGUMENTS: {

								_set_error("Too few arguments for "+errwhere+".");
							} break;
							default: {
								_set_error("Invalid arguments for "+errwhere+".");

							} break;
						}

						return p_node;
					}

					ConstantNode *cn = alloc_node<ConstantNode>();
					cn->value=v;
					return cn;

				} else if (op->arguments[0]->type==Node::TYPE_BUILT_IN_FUNCTION && last_not_constant==0) {





				}

				return op; //don't reduce yet
			} else if (op->op==OperatorNode::OP_INDEX) {
				//can reduce indices into constant arrays or dictionaries

				if (all_constants) {

					ConstantNode *ca = static_cast<ConstantNode*>(op->arguments[0]);
					ConstantNode *cb = static_cast<ConstantNode*>(op->arguments[1]);



					bool valid;

					Variant v = ca->value.get(cb->value,&valid);
					if (!valid) {
						_set_error("invalid index in constant expression");
						return op;
					}

					ConstantNode *cn = alloc_node<ConstantNode>();
					cn->value=v;
					return cn;

				} else if (op->arguments[0]->type==Node::TYPE_CONSTANT && op->arguments[1]->type==Node::TYPE_IDENTIFIER) {

					ConstantNode *ca = static_cast<ConstantNode*>(op->arguments[0]);
					IdentifierNode *ib = static_cast<IdentifierNode*>(op->arguments[1]);

					bool valid;
					Variant v = ca->value.get_named(ib->name,&valid);
					if (!valid) {
						_set_error("invalid index '"+String(ib->name)+"' in constant expression");
						return op;
					}

					ConstantNode *cn = alloc_node<ConstantNode>();
					cn->value=v;
					return cn;

				}

				return op;
			}

			//validate assignment (don't assign to cosntant expression
			switch(op->op) {

				case OperatorNode::OP_ASSIGN:
				case OperatorNode::OP_ASSIGN_ADD:
				case OperatorNode::OP_ASSIGN_SUB:
				case OperatorNode::OP_ASSIGN_MUL:
				case OperatorNode::OP_ASSIGN_DIV:
				case OperatorNode::OP_ASSIGN_MOD:
				case OperatorNode::OP_ASSIGN_SHIFT_LEFT:
				case OperatorNode::OP_ASSIGN_SHIFT_RIGHT:
				case OperatorNode::OP_ASSIGN_BIT_AND:
				case OperatorNode::OP_ASSIGN_BIT_OR:
				case OperatorNode::OP_ASSIGN_BIT_XOR: {

					if (op->arguments[0]->type==Node::TYPE_CONSTANT) {
						_set_error("Can't assign to constant");
						return op;
					}

				} break;
				default: { break; }
			}
			//now se if all are constants
			if (!all_constants)
				return op; //nothing to reduce from here on
#define _REDUCE_UNARY(m_vop)\
	bool valid=false;\
	Variant res;\
	Variant::evaluate(m_vop,static_cast<ConstantNode*>(op->arguments[0])->value,Variant(),res,valid);\
	if (!valid) {\
		_set_error("Invalid operand for unary operator");\
		return p_node;\
	}\
	ConstantNode *cn = alloc_node<ConstantNode>();\
	cn->value=res;\
	return cn;

#define _REDUCE_BINARY(m_vop)\
	bool valid=false;\
	Variant res;\
	Variant::evaluate(m_vop,static_cast<ConstantNode*>(op->arguments[0])->value,static_cast<ConstantNode*>(op->arguments[1])->value,res,valid);\
	if (!valid) {\
		_set_error("Invalid operands for operator");\
		return p_node;\
	}\
	ConstantNode *cn = alloc_node<ConstantNode>();\
	cn->value=res;\
	return cn;

			switch(op->op) {

				//unary operators
				case OperatorNode::OP_NEG: { _REDUCE_UNARY(Variant::OP_NEGATE); } break;
				case OperatorNode::OP_NOT: { _REDUCE_UNARY(Variant::OP_NOT); } break;
				case OperatorNode::OP_BIT_INVERT: { _REDUCE_UNARY(Variant::OP_BIT_NEGATE); } break;
				//binary operators (in precedence order)
				case OperatorNode::OP_IN: { _REDUCE_BINARY(Variant::OP_IN); } break;
				case OperatorNode::OP_EQUAL: { _REDUCE_BINARY(Variant::OP_EQUAL); } break;
				case OperatorNode::OP_NOT_EQUAL: { _REDUCE_BINARY(Variant::OP_NOT_EQUAL); } break;
				case OperatorNode::OP_LESS: { _REDUCE_BINARY(Variant::OP_LESS); } break;
				case OperatorNode::OP_LESS_EQUAL: {  _REDUCE_BINARY(Variant::OP_LESS_EQUAL); } break;
				case OperatorNode::OP_GREATER: { _REDUCE_BINARY(Variant::OP_GREATER); } break;
				case OperatorNode::OP_GREATER_EQUAL: { _REDUCE_BINARY(Variant::OP_GREATER_EQUAL); } break;
				case OperatorNode::OP_AND: { _REDUCE_BINARY(Variant::OP_AND); } break;
				case OperatorNode::OP_OR: { _REDUCE_BINARY(Variant::OP_OR); } break;
				case OperatorNode::OP_ADD: { _REDUCE_BINARY(Variant::OP_ADD); } break;
				case OperatorNode::OP_SUB: { _REDUCE_BINARY(Variant::OP_SUBSTRACT); } break;
				case OperatorNode::OP_MUL: { _REDUCE_BINARY(Variant::OP_MULTIPLY); } break;
				case OperatorNode::OP_DIV: { _REDUCE_BINARY(Variant::OP_DIVIDE); } break;
				case OperatorNode::OP_MOD: { _REDUCE_BINARY(Variant::OP_MODULE); } break;
				case OperatorNode::OP_SHIFT_LEFT: { _REDUCE_BINARY(Variant::OP_SHIFT_LEFT); } break;
				case OperatorNode::OP_SHIFT_RIGHT: { _REDUCE_BINARY(Variant::OP_SHIFT_RIGHT); } break;
				case OperatorNode::OP_BIT_AND: { _REDUCE_BINARY(Variant::OP_BIT_AND); } break;
				case OperatorNode::OP_BIT_OR: { _REDUCE_BINARY(Variant::OP_BIT_OR); } break;
				case OperatorNode::OP_BIT_XOR: { _REDUCE_BINARY(Variant::OP_BIT_XOR); } break;
				default: { ERR_FAIL_V(op); }
			}

			ERR_FAIL_V(op);
		} break;
		default: {
			return p_node;
		} break;

	}
}

GDParser::Node* GDParser::_parse_and_reduce_expression(Node *p_parent,bool p_static,bool p_reduce_const,bool p_allow_assign) {

	Node* expr=_parse_expression(p_parent,p_static,p_allow_assign);
	if (!expr || error_set)
		return NULL;
	expr = _reduce_expression(expr,p_reduce_const);
	if (!expr || error_set)
		return NULL;
	return expr;
}

void GDParser::_parse_block(BlockNode *p_block,bool p_static) {

	int indent_level = tab_level.back()->get();


#ifdef DEBUG_ENABLED

	NewLineNode *nl = alloc_node<NewLineNode>();

	nl->line=tokenizer.get_token_line();
	p_block->statements.push_back(nl);
#endif

	while(true) {

		GDTokenizer::Token token = tokenizer.get_token();
		if (error_set)
			return;

		if (indent_level>tab_level.back()->get()) {
			p_block->end_line=tokenizer.get_token_line();
			return; //go back a level
		}

		switch(token) {


			case GDTokenizer::TK_EOF:
				p_block->end_line=tokenizer.get_token_line();
			case GDTokenizer::TK_ERROR: {
				return; //go back

				//end of file!

			} break;
			case GDTokenizer::TK_NEWLINE: {

				NewLineNode *nl = alloc_node<NewLineNode>();
				nl->line=tokenizer.get_token_line();
				p_block->statements.push_back(nl);

				if (!_parse_newline()) {
					if (!error_set) {
						p_block->end_line=tokenizer.get_token_line();
					}
					return;
				}
			} break;
			case GDTokenizer::TK_CF_PASS: {
				if (tokenizer.get_token(1)!=GDTokenizer::TK_SEMICOLON && tokenizer.get_token(1)!=GDTokenizer::TK_NEWLINE ) {

					_set_error("Expected ';' or <NewLine>.");
					return;
				}
				tokenizer.advance();
			} break;
			case GDTokenizer::TK_PR_VAR: {
				//variale declaration and (eventual) initialization

				tokenizer.advance();
				if (tokenizer.get_token()!=GDTokenizer::TK_IDENTIFIER) {

					_set_error("Expected identifier for local variable name.");
					return;
				}
				StringName n = tokenizer.get_token_identifier();
				tokenizer.advance();

				p_block->variables.push_back(n); //line?
				p_block->variable_lines.push_back(tokenizer.get_token_line());


				//must know when the local variable is declared
				LocalVarNode *lv = alloc_node<LocalVarNode>();
				lv->name=n;
				p_block->statements.push_back(lv);

				Node *assigned=NULL;

				if (tokenizer.get_token()==GDTokenizer::TK_OP_ASSIGN) {

					tokenizer.advance();
					Node *subexpr=NULL;

					subexpr = _parse_and_reduce_expression(p_block,p_static);
					if (!subexpr)
						return;

					lv->assign=subexpr;
					assigned=subexpr;
				} else {

					ConstantNode *c = alloc_node<ConstantNode>();
					c->value=Variant();
					assigned = c;

				}
				IdentifierNode *id = alloc_node<IdentifierNode>();
				id->name=n;


				OperatorNode *op = alloc_node<OperatorNode>();
				op->op=OperatorNode::OP_ASSIGN;
				op->arguments.push_back(id);
				op->arguments.push_back(assigned);
				p_block->statements.push_back(op);

				_end_statement();


			} break;
			case GDTokenizer::TK_CF_IF: {

				tokenizer.advance();
				Node *condition = _parse_and_reduce_expression(p_block,p_static);
				if (!condition)
					return;

				ControlFlowNode *cf_if = alloc_node<ControlFlowNode>();

				cf_if->cf_type=ControlFlowNode::CF_IF;
				cf_if->arguments.push_back(condition);

				cf_if->body = alloc_node<BlockNode>();
				p_block->sub_blocks.push_back(cf_if->body);

				if (!_enter_indent_block(cf_if->body)) {
					p_block->end_line=tokenizer.get_token_line();
					return;
				}

				_parse_block(cf_if->body,p_static);
				if (error_set)
					return;
				p_block->statements.push_back(cf_if);

				while(true) {

					while(tokenizer.get_token()==GDTokenizer::TK_NEWLINE) {
						tokenizer.advance();
					}

					if (tab_level.back()->get() < indent_level) { //not at current indent level
						p_block->end_line=tokenizer.get_token_line();
						return;
					}

					if (tokenizer.get_token()==GDTokenizer::TK_CF_ELIF) {

						if (tab_level.back()->get() > indent_level) {

							_set_error("Invalid indent");
							return;
						}

						tokenizer.advance();

						cf_if->body_else=alloc_node<BlockNode>();
						p_block->sub_blocks.push_back(cf_if->body_else);

						ControlFlowNode *cf_else = alloc_node<ControlFlowNode>();
						cf_else->cf_type=ControlFlowNode::CF_IF;

						//condition
						Node *condition = _parse_and_reduce_expression(p_block,p_static);
						if (!condition)
							return;
						cf_else->arguments.push_back(condition);
						cf_else->cf_type=ControlFlowNode::CF_IF;

						cf_if->body_else->statements.push_back(cf_else);
						cf_if=cf_else;
						cf_if->body=alloc_node<BlockNode>();
						p_block->sub_blocks.push_back(cf_if->body);


						if (!_enter_indent_block(cf_if->body)) {
							p_block->end_line=tokenizer.get_token_line();
							return;
						}

						_parse_block(cf_else->body,p_static);
						if (error_set)
							return;


					} else if (tokenizer.get_token()==GDTokenizer::TK_CF_ELSE) {

						if (tab_level.back()->get() > indent_level) {

							_set_error("Invalid indent");
							return;
						}


						tokenizer.advance();
						cf_if->body_else=alloc_node<BlockNode>();
						p_block->sub_blocks.push_back(cf_if->body_else);

						if (!_enter_indent_block(cf_if->body_else)) {
							p_block->end_line=tokenizer.get_token_line();
							return;
						}
						_parse_block(cf_if->body_else,p_static);
						if (error_set)
							return;


						break; //after else, exit

					} else
						break;

				}


			} break;
			case GDTokenizer::TK_CF_WHILE: {

				tokenizer.advance();
				Node *condition = _parse_and_reduce_expression(p_block,p_static);
				if (!condition)
					return;

				ControlFlowNode *cf_while = alloc_node<ControlFlowNode>();

				cf_while->cf_type=ControlFlowNode::CF_WHILE;
				cf_while->arguments.push_back(condition);

				cf_while->body = alloc_node<BlockNode>();
				p_block->sub_blocks.push_back(cf_while->body);

				if (!_enter_indent_block(cf_while->body)) {
					p_block->end_line=tokenizer.get_token_line();
					return;
				}

				_parse_block(cf_while->body,p_static);
				if (error_set)
					return;
				p_block->statements.push_back(cf_while);
			} break;
			case GDTokenizer::TK_CF_FOR: {

				tokenizer.advance();

				if (tokenizer.get_token()!=GDTokenizer::TK_IDENTIFIER) {

					_set_error("identifier expected after 'for'");
				}

				IdentifierNode *id = alloc_node<IdentifierNode>();
				id->name=tokenizer.get_token_identifier();

				tokenizer.advance();

				if (tokenizer.get_token()!=GDTokenizer::TK_OP_IN) {
					_set_error("'in' expected after identifier");
					return;
				}

				tokenizer.advance();

				Node *container = _parse_and_reduce_expression(p_block,p_static);
				if (!container)
					return;

				ControlFlowNode *cf_for = alloc_node<ControlFlowNode>();

				cf_for->cf_type=ControlFlowNode::CF_FOR;
				cf_for->arguments.push_back(id);
				cf_for->arguments.push_back(container);

				cf_for->body = alloc_node<BlockNode>();
				p_block->sub_blocks.push_back(cf_for->body);

				if (!_enter_indent_block(cf_for->body)) {
					p_block->end_line=tokenizer.get_token_line();
					return;
				}

				_parse_block(cf_for->body,p_static);
				if (error_set)
					return;
				p_block->statements.push_back(cf_for);
			} break;
			case GDTokenizer::TK_CF_CONTINUE: {

				tokenizer.advance();
				ControlFlowNode *cf_continue = alloc_node<ControlFlowNode>();
				cf_continue->cf_type=ControlFlowNode::CF_CONTINUE;
				p_block->statements.push_back(cf_continue);
				if (!_end_statement()) {
					_set_error("Expected end of statement (continue)");
					return;
				}
			} break;
			case GDTokenizer::TK_CF_BREAK: {

				tokenizer.advance();
				ControlFlowNode *cf_break = alloc_node<ControlFlowNode>();
				cf_break->cf_type=ControlFlowNode::CF_BREAK;
				p_block->statements.push_back(cf_break);
				if (!_end_statement()) {
					_set_error("Expected end of statement (break)");
					return;
				}
			} break;
			case GDTokenizer::TK_CF_RETURN: {

				tokenizer.advance();
				ControlFlowNode *cf_return = alloc_node<ControlFlowNode>();
				cf_return->cf_type=ControlFlowNode::CF_RETURN;



				if (tokenizer.get_token()==GDTokenizer::TK_SEMICOLON || tokenizer.get_token()==GDTokenizer::TK_NEWLINE || tokenizer.get_token()==GDTokenizer::TK_EOF) {
					//expect end of statement
					p_block->statements.push_back(cf_return);
					if (!_end_statement()) {
						return;
					}
				} else {
					//expect expression
					Node *retexpr = _parse_and_reduce_expression(p_block,p_static);
					if (!retexpr)
						return;
					cf_return->arguments.push_back(retexpr);
					p_block->statements.push_back(cf_return);
					if (!_end_statement()) {
						_set_error("Expected end of statement after return expression.");
						return;
					}
				}


			} break;
			case GDTokenizer::TK_PR_ASSERT: {

				tokenizer.advance();
				Node *condition = _parse_and_reduce_expression(p_block,p_static);
				if (!condition)
					return;
				AssertNode *an = alloc_node<AssertNode>();
				an->condition=condition;
				p_block->statements.push_back(an);

				if (!_end_statement()) {
					_set_error("Expected end of statement after assert.");
					return;
				}
			} break;
			default: {

				Node *expression = _parse_and_reduce_expression(p_block,p_static,false,true);
				if (!expression)
					return;
				p_block->statements.push_back(expression);
				if (!_end_statement()) {
					_set_error("Expected end of statement after expression.");
					return;
				}

			} break;
			/*
			case GDTokenizer::TK_CF_LOCAL: {

				if (tokenizer.get_token(1)!=GDTokenizer::TK_SEMICOLON && tokenizer.get_token(1)!=GDTokenizer::TK_NEWLINE ) {

					_set_error("Expected ';' or <NewLine>.");
				}
				tokenizer.advance();
			} break;
			*/

		}
	}

}

bool GDParser::_parse_newline() {

	if (tokenizer.get_token(1)!=GDTokenizer::TK_EOF && tokenizer.get_token(1)!=GDTokenizer::TK_NEWLINE) {

		int indent = tokenizer.get_token_line_indent();
		int current_indent = tab_level.back()->get();

		if (indent>current_indent) {
			_set_error("Unexpected indent.");
			return false;
		}

		if (indent<current_indent) {

			while(indent<current_indent) {

				//exit block
				if (tab_level.size()==1) {
					_set_error("Invalid indent. BUG?");
					return false;
				}

				tab_level.pop_back();

				if (tab_level.back()->get()<indent) {

					_set_error("Unindent does not match any outer indentation level.");
					return false;
				}
				current_indent = tab_level.back()->get();
			}

			tokenizer.advance();
			return false;
		}
	}

	tokenizer.advance();
	return true;

}


void GDParser::_parse_extends(ClassNode *p_class) {


	if (p_class->extends_used) {

		_set_error("'extends' already used for this class.");
		return;
	}

	if (!p_class->constant_expressions.empty() || !p_class->subclasses.empty() || !p_class->functions.empty() || !p_class->variables.empty()) {

		_set_error("'extends' must be used before anything else.");
		return;
	}

	p_class->extends_used=true;

	//see if inheritance happens from a file
	tokenizer.advance();

	if (tokenizer.get_token()==GDTokenizer::TK_CONSTANT) {

		Variant constant = tokenizer.get_token_constant();
		if (constant.get_type()!=Variant::STRING) {

			_set_error("'extends' constant must be a string.");
			return;
		}

		p_class->extends_file=constant;
		tokenizer.advance();

		if (tokenizer.get_token()!=GDTokenizer::TK_PERIOD) {
			return;
		} else
			tokenizer.advance();

	}

	while(true) {
		if (tokenizer.get_token()!=GDTokenizer::TK_IDENTIFIER) {

			_set_error("Invalid 'extends' syntax, expected string constant (path) and/or identifier (parent class).");
			return;
		}

		StringName identifier=tokenizer.get_token_identifier();
		p_class->extends_class.push_back(identifier);

		tokenizer.advance(1);
		if (tokenizer.get_token()!=GDTokenizer::TK_PERIOD)
			return;
	}

}

void GDParser::_parse_class(ClassNode *p_class) {

	int indent_level = tab_level.back()->get();

	while(true) {

		GDTokenizer::Token token = tokenizer.get_token();
		if (error_set)
			return;

		if (indent_level>tab_level.back()->get()) {
			p_class->end_line=tokenizer.get_token_line();
			return; //go back a level
		}

		switch(token) {

			case GDTokenizer::TK_EOF:
				p_class->end_line=tokenizer.get_token_line();
			case GDTokenizer::TK_ERROR: {
				return; //go back
				//end of file!
			} break;
			case GDTokenizer::TK_NEWLINE: {
				if (!_parse_newline()) {
					if (!error_set) {
						p_class->end_line=tokenizer.get_token_line();
					}
					return;
				}
			} break;
			case GDTokenizer::TK_PR_EXTENDS: {

				_parse_extends(p_class);
				if (error_set)
					return;
				_end_statement();


			} break;
			case GDTokenizer::TK_PR_TOOL: {

				if (p_class->tool) {

					_set_error("tool used more than once");
					return;
				}

				p_class->tool=true;
				tokenizer.advance();

			} break;
			case GDTokenizer::TK_PR_CLASS: {
				//class inside class :D

				StringName name;
				StringName extends;

				if (tokenizer.get_token(1)!=GDTokenizer::TK_IDENTIFIER) {

					_set_error("'class' syntax: 'class <Name>:' or 'class <Name> extends <BaseClass>:'");
					return;
				}
				name = tokenizer.get_token_identifier(1);
				tokenizer.advance(2);

				ClassNode *newclass = alloc_node<ClassNode>();
				newclass->initializer = alloc_node<BlockNode>();
				newclass->name=name;

				p_class->subclasses.push_back(newclass);


				if (tokenizer.get_token()==GDTokenizer::TK_PR_EXTENDS) {

					_parse_extends(newclass);
					if (error_set)
						return;
				}

				if (!_enter_indent_block()) {

					_set_error("Indented block expected.");
					return;
				}
				_parse_class(newclass);

			} break;
			/* this is for functions....
			case GDTokenizer::TK_CF_PASS: {

				tokenizer.advance(1);
			} break;
			*/
			case GDTokenizer::TK_PR_STATIC: {
				tokenizer.advance();
				if (tokenizer.get_token()!=GDTokenizer::TK_PR_FUNCTION) {

					_set_error("Expected 'func'.");
					return;
				}

			}; //fallthrough to function
			case GDTokenizer::TK_PR_FUNCTION: {

				bool _static=false;

				if (tokenizer.get_token(-1)==GDTokenizer::TK_PR_STATIC) {

					_static=true;
				}


				if (tokenizer.get_token(1)!=GDTokenizer::TK_IDENTIFIER) {

					_set_error("Expected identifier after 'func' (syntax: 'func <identifier>([arguments]):' ).");
					return;
				}

				StringName name = tokenizer.get_token_identifier(1);

				for(int i=0;i<p_class->functions.size();i++) {
					if (p_class->functions[i]->name==name) {
						_set_error("Function '"+String(name)+"' already exists in this class (at line: "+itos(p_class->functions[i]->line)+").");
					}
				}
				for(int i=0;i<p_class->static_functions.size();i++) {
					if (p_class->static_functions[i]->name==name) {
						_set_error("Function '"+String(name)+"' already exists in this class (at line: "+itos(p_class->static_functions[i]->line)+").");
					}
				}
				tokenizer.advance(2);

				if (tokenizer.get_token()!=GDTokenizer::TK_PARENTHESIS_OPEN) {

					_set_error("Expected '(' after identifier (syntax: 'func <identifier>([arguments]):' ).");
					return;
				}

				tokenizer.advance();

				Vector<StringName> arguments;
				Vector<Node*> default_values;

				int fnline = tokenizer.get_token_line();


				if (tokenizer.get_token()!=GDTokenizer::TK_PARENTHESIS_CLOSE) {
					//has arguments
					bool defaulting=false;
					while(true) {

						if (tokenizer.get_token()==GDTokenizer::TK_PR_VAR) {

							tokenizer.advance(); //var before the identifier is allowed
						}


						if (tokenizer.get_token()!=GDTokenizer::TK_IDENTIFIER) {

							_set_error("Expected identifier for argument.");
							return;
						}

						StringName argname=tokenizer.get_token_identifier();
						arguments.push_back(argname);

						tokenizer.advance();

						if (defaulting && tokenizer.get_token()!=GDTokenizer::TK_OP_ASSIGN) {

							_set_error("Default parameter expected.");
							return;
						}

						//tokenizer.advance();


						if (tokenizer.get_token()==GDTokenizer::TK_OP_ASSIGN) {
							defaulting=true;
							tokenizer.advance(1);
							Node *defval=NULL;

							defval=_parse_and_reduce_expression(p_class,_static);
							if (!defval || error_set)
								return;

							OperatorNode *on = alloc_node<OperatorNode>();
							on->op=OperatorNode::OP_ASSIGN;

							IdentifierNode *in = alloc_node<IdentifierNode>();
							in->name=argname;

							on->arguments.push_back(in);
							on->arguments.push_back(defval);
							/* no ..
							if (defval->type!=Node::TYPE_CONSTANT) {

								_set_error("default argument must be constant");
							}
							*/
							default_values.push_back(on);
						}

						if (tokenizer.get_token()==GDTokenizer::TK_COMMA) {
							tokenizer.advance();
							continue;
						} else if (tokenizer.get_token()!=GDTokenizer::TK_PARENTHESIS_CLOSE) {

							_set_error("Expected ',' or ')'.");
							return;
						}

						break;
					}


				}

				tokenizer.advance();

				BlockNode *block = alloc_node<BlockNode>();

				if (name=="_init") {

					if (p_class->extends_used) {

						OperatorNode *cparent = alloc_node<OperatorNode>();
						cparent->op=OperatorNode::OP_PARENT_CALL;
						block->statements.push_back(cparent);

						IdentifierNode *id = alloc_node<IdentifierNode>();
						id->name="_init";
						cparent->arguments.push_back(id);

						if (tokenizer.get_token()==GDTokenizer::TK_PERIOD) {
							tokenizer.advance();
							if (tokenizer.get_token()!=GDTokenizer::TK_PARENTHESIS_OPEN) {
								_set_error("expected '(' for parent constructor arguments.");
							}
							tokenizer.advance();

							if (tokenizer.get_token()!=GDTokenizer::TK_PARENTHESIS_CLOSE) {
								//has arguments
								while(true) {

									Node *arg = _parse_and_reduce_expression(p_class,_static);
									cparent->arguments.push_back(arg);

									if (tokenizer.get_token()==GDTokenizer::TK_COMMA) {
										tokenizer.advance();
										continue;
									} else if (tokenizer.get_token()!=GDTokenizer::TK_PARENTHESIS_CLOSE) {

										_set_error("Expected ',' or ')'.");
										return;
									}

									break;

								}
							}

							tokenizer.advance();
						}
					} else {


						if (tokenizer.get_token()==GDTokenizer::TK_PERIOD) {

							_set_error("Parent constructor call found for a class without inheritance.");
							return;
						}

					}
				}

				if (!_enter_indent_block(block)) {

					_set_error("Indented block expected.");
					return;
				}

				FunctionNode *function = alloc_node<FunctionNode>();
				function->name=name;
				function->arguments=arguments;
				function->default_values=default_values;
				function->_static=_static;
				function->line=fnline;


				if (_static)
					p_class->static_functions.push_back(function);
				else
					p_class->functions.push_back(function);


				_parse_block(block,_static);
				function->body=block;
				//arguments
			} break;
			case GDTokenizer::TK_PR_EXPORT: {

				tokenizer.advance();

				if (tokenizer.get_token()==GDTokenizer::TK_PARENTHESIS_OPEN) {

					tokenizer.advance();
					if (tokenizer.get_token()==GDTokenizer::TK_BUILT_IN_TYPE) {

						Variant::Type type = tokenizer.get_token_type();
						if (type==Variant::NIL) {
							_set_error("Can't export null type.");
							return;
						}
						current_export.type=type;
						tokenizer.advance();
						if (tokenizer.get_token()==GDTokenizer::TK_COMMA) {
							// hint expected next!
							tokenizer.advance();
							switch(current_export.type) {


								case Variant::INT: {

									if (tokenizer.get_token()==GDTokenizer::TK_CONSTANT && tokenizer.get_token_constant().get_type()==Variant::STRING) {
										//enumeration
										current_export.hint=PROPERTY_HINT_ENUM;
										bool first=true;
										while(true) {

											if (tokenizer.get_token()!=GDTokenizer::TK_CONSTANT || tokenizer.get_token_constant().get_type()!=Variant::STRING) {

												current_export=PropertyInfo();
												_set_error("Expected a string constant in enumeration hint.");
											}

											String c = tokenizer.get_token_constant();
											if (!first)
												current_export.hint_string+=",";
											else
												first=false;

											current_export.hint_string+=c.xml_escape();

											tokenizer.advance();
											if (tokenizer.get_token()==GDTokenizer::TK_PARENTHESIS_CLOSE)
												break;

											if (tokenizer.get_token()!=GDTokenizer::TK_COMMA) {
												current_export=PropertyInfo();
												_set_error("Expected ')' or ',' in enumeration hint.");
											}

											tokenizer.advance();

										}

										break;
									}

								};
								case Variant::REAL: {

									if (tokenizer.get_token()!=GDTokenizer::TK_CONSTANT || !tokenizer.get_token_constant().is_num()) {

										current_export=PropertyInfo();
										_set_error("Expected a range in numeric hint.");

									}
										//enumeration
									current_export.hint=PROPERTY_HINT_RANGE;

									current_export.hint_string=tokenizer.get_token_constant().operator String();
									tokenizer.advance();

									if (tokenizer.get_token()==GDTokenizer::TK_PARENTHESIS_CLOSE) {
										current_export.hint_string="0,"+current_export.hint_string;
										break;
									}

									if (tokenizer.get_token()!=GDTokenizer::TK_COMMA) {

										current_export=PropertyInfo();
										_set_error("Expected ',' or ')' in numeric range hint.");
									}

									tokenizer.advance();

									if (tokenizer.get_token()!=GDTokenizer::TK_CONSTANT || !tokenizer.get_token_constant().is_num()) {

										current_export=PropertyInfo();
										_set_error("Expected a number as upper bound in numeric range hint.");
									}

									current_export.hint_string+=","+tokenizer.get_token_constant().operator String();
									tokenizer.advance();

									if (tokenizer.get_token()==GDTokenizer::TK_PARENTHESIS_CLOSE)
										break;

									if (tokenizer.get_token()!=GDTokenizer::TK_COMMA) {

										current_export=PropertyInfo();
										_set_error("Expected ',' or ')' in numeric range hint.");
									}

									tokenizer.advance();

									if (tokenizer.get_token()!=GDTokenizer::TK_CONSTANT || !tokenizer.get_token_constant().is_num()) {

										current_export=PropertyInfo();
										_set_error("Expected a number as step in numeric range hint.");
									}

									current_export.hint_string+=","+tokenizer.get_token_constant().operator String();
									tokenizer.advance();

								} break;
								case Variant::STRING: {

									if (tokenizer.get_token()==GDTokenizer::TK_CONSTANT && tokenizer.get_token_constant().get_type()==Variant::STRING) {
										//enumeration
										current_export.hint=PROPERTY_HINT_ENUM;
										bool first=true;
										while(true) {

											if (tokenizer.get_token()!=GDTokenizer::TK_CONSTANT || tokenizer.get_token_constant().get_type()!=Variant::STRING) {

												current_export=PropertyInfo();
												_set_error("Expected a string constant in enumeration hint.");
											}

											String c = tokenizer.get_token_constant();
											if (!first)
												current_export.hint_string+=",";
											else
												first=false;

											current_export.hint_string+=c.xml_escape();
											tokenizer.advance();
											if (tokenizer.get_token()==GDTokenizer::TK_PARENTHESIS_CLOSE)
												break;

											if (tokenizer.get_token()!=GDTokenizer::TK_COMMA) {
												current_export=PropertyInfo();
												_set_error("Expected ')' or ',' in enumeration hint.");
												return;
											}
											tokenizer.advance();

										}

										break;
									}

									if (tokenizer.get_token()==GDTokenizer::TK_IDENTIFIER && tokenizer.get_token_identifier()=="DIR") {

										current_export.hint=PROPERTY_HINT_DIR;
										tokenizer.advance();
										if (tokenizer.get_token()!=GDTokenizer::TK_PARENTHESIS_CLOSE) {
											_set_error("Expected ')' in hint.");
											return;
										}
										break;
									}

									if (tokenizer.get_token()==GDTokenizer::TK_IDENTIFIER && tokenizer.get_token_identifier()=="FILE") {

										current_export.hint=PROPERTY_HINT_FILE;
										tokenizer.advance();

										if (tokenizer.get_token()==GDTokenizer::TK_COMMA) {

											tokenizer.advance();
											if (tokenizer.get_token()!=GDTokenizer::TK_CONSTANT || tokenizer.get_token_constant().get_type()!=Variant::STRING) {

												_set_error("Expected string constant with filter");
												return;
											}
											current_export.hint_string=tokenizer.get_token_constant();
											tokenizer.advance();

										}

										if (tokenizer.get_token()!=GDTokenizer::TK_PARENTHESIS_CLOSE) {
											_set_error("Expected ')' in hint.");
											return;
										}
										break;
									}
								} break;
								case Variant::COLOR: {

									if (tokenizer.get_token()!=GDTokenizer::TK_IDENTIFIER ) {

										current_export=PropertyInfo();
										_set_error("Color type hint expects RGB or RGBA as hints");
										return;
									}

									String identifier = tokenizer.get_token_identifier();
									if (identifier=="RGB") {
										current_export.hint=PROPERTY_HINT_COLOR_NO_ALPHA;
									} else if (identifier=="RGBA") {
										//none
									} else {
										current_export=PropertyInfo();
										_set_error("Color type hint expects RGB or RGBA as hints");
										return;
									}
									tokenizer.advance();

								} break;
								default: {

									current_export=PropertyInfo();
									_set_error("Type '"+Variant::get_type_name(type)+"' can't take hints.");
									return;
								} break;
							}

						}

					} else if (tokenizer.get_token()==GDTokenizer::TK_IDENTIFIER) {

						String identifier = tokenizer.get_token_identifier();
						if (!ObjectTypeDB::is_type(identifier,"Resource")) {

							current_export=PropertyInfo();
							_set_error("Export hint not a type or resource.");
						}

						current_export.type=Variant::OBJECT;
						current_export.hint=PROPERTY_HINT_RESOURCE_TYPE;
						current_export.hint_string=identifier;

						tokenizer.advance();
					}

					if (tokenizer.get_token()!=GDTokenizer::TK_PARENTHESIS_CLOSE) {

						current_export=PropertyInfo();
						_set_error("Expected ')' or ',' after export hint.");
						return;

					}

					tokenizer.advance();

				}

				if (tokenizer.get_token()!=GDTokenizer::TK_PR_VAR) {

					current_export=PropertyInfo();
					_set_error("Expected 'var'.");
					return;
				}

			}; //fallthrough to var
			case GDTokenizer::TK_PR_VAR: {
				//variale declaration and (eventual) initialization

				ClassNode::Member member;
				bool autoexport = tokenizer.get_token(-1)==GDTokenizer::TK_PR_EXPORT;
				if (current_export.type!=Variant::NIL) {
					member._export=current_export;
					current_export=PropertyInfo();
				}

				tokenizer.advance();
				if (tokenizer.get_token()!=GDTokenizer::TK_IDENTIFIER) {

					_set_error("Expected identifier for member variable name.");
					return;
				}

				member.identifier=tokenizer.get_token_identifier();
				member._export.name=member.identifier;
				tokenizer.advance();

				p_class->variables.push_back(member);

				if (tokenizer.get_token()!=GDTokenizer::TK_OP_ASSIGN) {

					if (autoexport) {

						_set_error("Type-less export needs a constant expression assigned to infer type.");
						return;
					}
					break;
				}
#ifdef DEBUG_ENABLED
				int line = tokenizer.get_token_line();
#endif
				tokenizer.advance();

				Node *subexpr=NULL;

				subexpr = _parse_and_reduce_expression(p_class,false);
				if (!subexpr)
					return;

				if (autoexport) {
					if (subexpr->type==Node::TYPE_ARRAY) {

						p_class->variables[p_class->variables.size()-1]._export.type=Variant::ARRAY;

					} else if (subexpr->type==Node::TYPE_DICTIONARY) {

						p_class->variables[p_class->variables.size()-1]._export.type=Variant::DICTIONARY;

					} else {

						if (subexpr->type!=Node::TYPE_CONSTANT) {

							_set_error("Type-less export needs a constant expression assigned to infer type.");
							return;
						}

						ConstantNode *cn = static_cast<ConstantNode*>(subexpr);
						if (cn->value.get_type()==Variant::NIL) {

							_set_error("Can't accept a null constant expression for infering export type.");
							return;
						}
						p_class->variables[p_class->variables.size()-1]._export.type=cn->value.get_type();
					}
				}
#ifdef TOOLS_ENABLED
				if (subexpr->type==Node::TYPE_CONSTANT && p_class->variables[p_class->variables.size()-1]._export.type!=Variant::NIL) {

					ConstantNode *cn = static_cast<ConstantNode*>(subexpr);
					if (cn->value.get_type()!=Variant::NIL) {
						p_class->variables[p_class->variables.size()-1].default_value=cn->value;
					}
				}
#endif



				IdentifierNode *id = alloc_node<IdentifierNode>();
				id->name=member.identifier;

				OperatorNode *op = alloc_node<OperatorNode>();
				op->op=OperatorNode::OP_ASSIGN;
				op->arguments.push_back(id);
				op->arguments.push_back(subexpr);

#ifdef DEBUG_ENABLED
				NewLineNode *nl = alloc_node<NewLineNode>();
				nl->line=line;
				p_class->initializer->statements.push_back(nl);
#endif
				p_class->initializer->statements.push_back(op);

				_end_statement();

			} break;
			case GDTokenizer::TK_PR_CONST: {
				//variale declaration and (eventual) initialization

				ClassNode::Constant constant;

				tokenizer.advance();
				if (tokenizer.get_token()!=GDTokenizer::TK_IDENTIFIER) {

					_set_error("Expected name (identifier) for constant.");
					return;
				}

				constant.identifier=tokenizer.get_token_identifier();
				tokenizer.advance();

				if (tokenizer.get_token()!=GDTokenizer::TK_OP_ASSIGN) {
					_set_error("Constant expects assignment.");
					return;
				}

				tokenizer.advance();

				Node *subexpr=NULL;

				subexpr = _parse_and_reduce_expression(p_class,true,true);
				if (!subexpr)
					return;

				if (subexpr->type!=Node::TYPE_CONSTANT) {
					_set_error("Expected constant expression");
				}
				constant.expression=subexpr;

				p_class->constant_expressions.push_back(constant);

				_end_statement();


			} break;


			default: {

				_set_error(String()+"Unexpected token: "+tokenizer.get_token_name(tokenizer.get_token())+":"+tokenizer.get_token_identifier());
				return;

			} break;

		}

	}


}


void GDParser::_set_error(const String& p_error, int p_line, int p_column) {


	if (error_set)
		return; //allow no further errors

	error=p_error;
	error_line=p_line<0?tokenizer.get_token_line():p_line;
	error_column=p_column<0?tokenizer.get_token_column():p_column;
	error_set=true;
}

String GDParser::get_error() const {

	return error;
}

int GDParser::get_error_line() const {

	return error_line;
}
int GDParser::get_error_column() const {

	return error_column;
}


Error GDParser::parse(const String& p_code,const String& p_base_path) {

	base_path=p_base_path;

	tokenizer.set_code(p_code);

	clear();

	//assume class
	ClassNode *main_class = alloc_node<ClassNode>();
	main_class->initializer = alloc_node<BlockNode>();

	_parse_class(main_class);

	if (tokenizer.get_token()==GDTokenizer::TK_ERROR) {
		error_set=false;
		_set_error("Parse Error: "+tokenizer.get_token_error());
	}

	if (error_set) {

		return ERR_PARSE_ERROR;
	}
	return OK;
}

const GDParser::Node *GDParser::get_parse_tree() const {

	return head;
}

void GDParser::clear() {

	while(list) {

		Node *l=list;
		list=list->next;
		memdelete(l);
	}

	head=NULL;
	list=NULL;

	error_set=false;
	tab_level.clear();
	tab_level.push_back(0);
	error_line=0;
	error_column=0;
	current_export.type=Variant::NIL;
	error="";

}

GDParser::GDParser() {

	head=NULL;
	list=NULL;
	clear();

}

GDParser::~GDParser() {

	clear();
}