godot/modules/gdscript/gd_tokenizer.cpp

/*************************************************************************/
/*  gd_tokenizer.cpp                                                     */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                      https://godotengine.org                          */
/*************************************************************************/
/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md).   */
/*                                                                       */
/* 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_tokenizer.h"
#include "gd_functions.h"
#include "io/marshalls.h"
#include "map.h"
#include "print_string.h"

const char *GDTokenizer::token_names[TK_MAX] = {
	"Empty",
	"Identifier",
	"Constant",
	"Self",
	"Built-In Type",
	"Built-In Func",
	"In",
	"'=='",
	"'!='",
	"'<'",
	"'<='",
	"'>'",
	"'>='",
	"'and'",
	"'or'",
	"'not'",
	"'+'",
	"'-'",
	"'*'",
	"'/'",
	"'%'",
	"'<<'",
	"'>>'",
	"'='",
	"'+='",
	"'-='",
	"'*='",
	"'/='",
	"'%='",
	"'<<='",
	"'>>='",
	"'&='",
	"'|='",
	"'^='",
	"'&'",
	"'|'",
	"'^'",
	"'~'",
	//"Plus Plus",
	//"Minus Minus",
	"if",
	"elif",
	"else",
	"for",
	"do",
	"while",
	"switch (reserved)",
	"case (reserved)",
	"break",
	"continue",
	"pass",
	"return",
	"func",
	"class",
	"extends",
	"onready",
	"tool",
	"static",
	"export",
	"setget",
	"const",
	"var",
	"enum",
	"preload",
	"assert",
	"yield",
	"signal",
	"breakpoint",
	"'['",
	"']'",
	"'{'",
	"'}'",
	"'('",
	"')'",
	"','",
	"';'",
	"'.'",
	"'?'",
	"':'",
	"'\\n'",
	"PI",
	"Error",
	"EOF",
	"Cursor"
};

const char *GDTokenizer::get_token_name(Token p_token) {

	ERR_FAIL_INDEX_V(p_token, TK_MAX, "<error>");
	return token_names[p_token];
}

static bool _is_text_char(CharType c) {

	return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || c == '_';
}

static bool _is_number(CharType c) {

	return (c >= '0' && c <= '9');
}

static bool _is_hex(CharType c) {

	return (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F');
}

void GDTokenizerText::_make_token(Token p_type) {

	TokenData &tk = tk_rb[tk_rb_pos];

	tk.type = p_type;
	tk.line = line;
	tk.col = column;

	tk_rb_pos = (tk_rb_pos + 1) % TK_RB_SIZE;
}
void GDTokenizerText::_make_identifier(const StringName &p_identifier) {

	TokenData &tk = tk_rb[tk_rb_pos];

	tk.type = TK_IDENTIFIER;
	tk.identifier = p_identifier;
	tk.line = line;
	tk.col = column;

	tk_rb_pos = (tk_rb_pos + 1) % TK_RB_SIZE;
}

void GDTokenizerText::_make_built_in_func(GDFunctions::Function p_func) {

	TokenData &tk = tk_rb[tk_rb_pos];

	tk.type = TK_BUILT_IN_FUNC;
	tk.func = p_func;
	tk.line = line;
	tk.col = column;

	tk_rb_pos = (tk_rb_pos + 1) % TK_RB_SIZE;
}
void GDTokenizerText::_make_constant(const Variant &p_constant) {

	TokenData &tk = tk_rb[tk_rb_pos];

	tk.type = TK_CONSTANT;
	tk.constant = p_constant;
	tk.line = line;
	tk.col = column;

	tk_rb_pos = (tk_rb_pos + 1) % TK_RB_SIZE;
}

void GDTokenizerText::_make_type(const Variant::Type &p_type) {

	TokenData &tk = tk_rb[tk_rb_pos];

	tk.type = TK_BUILT_IN_TYPE;
	tk.vtype = p_type;
	tk.line = line;
	tk.col = column;

	tk_rb_pos = (tk_rb_pos + 1) % TK_RB_SIZE;
}

void GDTokenizerText::_make_error(const String &p_error) {

	error_flag = true;
	last_error = p_error;

	TokenData &tk = tk_rb[tk_rb_pos];
	tk.type = TK_ERROR;
	tk.constant = p_error;
	tk.line = line;
	tk.col = column;
	tk_rb_pos = (tk_rb_pos + 1) % TK_RB_SIZE;
}

void GDTokenizerText::_make_newline(int p_spaces) {

	TokenData &tk = tk_rb[tk_rb_pos];
	tk.type = TK_NEWLINE;
	tk.constant = p_spaces;
	tk.line = line;
	tk.col = column;
	tk_rb_pos = (tk_rb_pos + 1) % TK_RB_SIZE;
}

void GDTokenizerText::_advance() {

	if (error_flag) {
		//parser broke
		_make_error(last_error);
		return;
	}

	if (code_pos >= len) {
		_make_token(TK_EOF);
		return;
	}
#define GETCHAR(m_ofs) ((m_ofs + code_pos) >= len ? 0 : _code[m_ofs + code_pos])
#define INCPOS(m_amount)      \
	{                         \
		code_pos += m_amount; \
		column += m_amount;   \
	}
	while (true) {

		bool is_node_path = false;
		StringMode string_mode = STRING_DOUBLE_QUOTE;

		switch (GETCHAR(0)) {
			case 0:
				_make_token(TK_EOF);
				break;
			case '\\':
				INCPOS(1);
				if (GETCHAR(0) == '\r') {
					INCPOS(1);
				}

				if (GETCHAR(0) != '\n') {
					_make_error("Expected newline after '\\'.");
					return;
				}

				INCPOS(1);
				line++;

				while (GETCHAR(0) == ' ' || GETCHAR(0) == '\t') {
					INCPOS(1);
				}

				continue;
			case '\t':
			case '\r':
			case ' ':
				INCPOS(1);
				continue;
			case '\n': {
				line++;
				INCPOS(1);
				column = 1;
				int i = 0;
				while (GETCHAR(i) == ' ' || GETCHAR(i) == '\t') {
					i++;
				}

				_make_newline(i);
				return;
			}
#if 1 //py style tokenizer
			case '#': { // line comment skip

				while (GETCHAR(0) != '\n') {
					code_pos++;
					if (GETCHAR(0) == 0) { //end of file
						//_make_error("Unterminated Comment");
						_make_token(TK_EOF);
						return;
					}
				}
				INCPOS(1);
				column = 1;
				line++;
				int i = 0;
				while (GETCHAR(i) == ' ' || GETCHAR(i) == '\t') {
					i++;
				}
				_make_newline(i);
				return;

			} break;
#endif
			case '/': {

				switch (GETCHAR(1)) {
#if 0 // c style tokenizer
					case '*': { // block comment
						int pos = code_pos+2;
						int new_line=line;
						int new_col=column+2;

						while(true) {
							if (_code[pos]=='0') {
								_make_error("Unterminated Comment");
								code_pos=pos;
								return;
							}
							if (_code[pos]=='*' && _code[pos+1]=='/') {
								new_col+=2;
								pos+=2; //compensate
								break;
							} else if (_code[pos]=='\n') {
								new_line++;
								new_col=1;
							} else {
								new_col++;
							}
							pos++;
						}

						column=new_col;
						line=new_line;
						code_pos=pos;
						continue;

					} break;
					case '/': { // line comment skip

						while(GETCHAR(0)!='\n') {
							code_pos++;
							if (GETCHAR(0)==0) { //end of file
								_make_error("Unterminated Comment");
								return;
							}
						}
						INCPOS(1);
						column=1;
						line++;
						continue;

					} break;
#endif
					case '=': { // diveq

						_make_token(TK_OP_ASSIGN_DIV);
						INCPOS(1);

					} break;
					default:
						_make_token(TK_OP_DIV);
				}
			} break;
			case '=': {
				if (GETCHAR(1) == '=') {
					_make_token(TK_OP_EQUAL);
					INCPOS(1);

				} else
					_make_token(TK_OP_ASSIGN);

			} break;
			case '<': {
				if (GETCHAR(1) == '=') {

					_make_token(TK_OP_LESS_EQUAL);
					INCPOS(1);
				} else if (GETCHAR(1) == '<') {
					if (GETCHAR(2) == '=') {
						_make_token(TK_OP_ASSIGN_SHIFT_LEFT);
						INCPOS(1);
					} else {
						_make_token(TK_OP_SHIFT_LEFT);
					}
					INCPOS(1);
				} else
					_make_token(TK_OP_LESS);

			} break;
			case '>': {
				if (GETCHAR(1) == '=') {
					_make_token(TK_OP_GREATER_EQUAL);
					INCPOS(1);
				} else if (GETCHAR(1) == '>') {
					if (GETCHAR(2) == '=') {
						_make_token(TK_OP_ASSIGN_SHIFT_RIGHT);
						INCPOS(1);

					} else {
						_make_token(TK_OP_SHIFT_RIGHT);
					}
					INCPOS(1);
				} else {
					_make_token(TK_OP_GREATER);
				}

			} break;
			case '!': {
				if (GETCHAR(1) == '=') {
					_make_token(TK_OP_NOT_EQUAL);
					INCPOS(1);
				} else {
					_make_token(TK_OP_NOT);
				}

			} break;
			//case '"' //string - no strings in shader
			//case '\'' //string - no strings in shader
			case '{':
				_make_token(TK_CURLY_BRACKET_OPEN);
				break;
			case '}':
				_make_token(TK_CURLY_BRACKET_CLOSE);
				break;
			case '[':
				_make_token(TK_BRACKET_OPEN);
				break;
			case ']':
				_make_token(TK_BRACKET_CLOSE);
				break;
			case '(':
				_make_token(TK_PARENTHESIS_OPEN);
				break;
			case ')':
				_make_token(TK_PARENTHESIS_CLOSE);
				break;
			case ',':
				_make_token(TK_COMMA);
				break;
			case ';':
				_make_token(TK_SEMICOLON);
				break;
			case '?':
				_make_token(TK_QUESTION_MARK);
				break;
			case ':':
				_make_token(TK_COLON); //for methods maybe but now useless.
				break;
			case '^': {
				if (GETCHAR(1) == '=') {
					_make_token(TK_OP_ASSIGN_BIT_XOR);
					INCPOS(1);
				} else {
					_make_token(TK_OP_BIT_XOR);
				}

			} break;
			case '~':
				_make_token(TK_OP_BIT_INVERT);
				break;
			case '&': {
				if (GETCHAR(1) == '&') {

					_make_token(TK_OP_AND);
					INCPOS(1);
				} else if (GETCHAR(1) == '=') {
					_make_token(TK_OP_ASSIGN_BIT_AND);
					INCPOS(1);
				} else {
					_make_token(TK_OP_BIT_AND);
				}
			} break;
			case '|': {
				if (GETCHAR(1) == '|') {

					_make_token(TK_OP_OR);
					INCPOS(1);
				} else if (GETCHAR(1) == '=') {
					_make_token(TK_OP_ASSIGN_BIT_OR);
					INCPOS(1);
				} else {
					_make_token(TK_OP_BIT_OR);
				}
			} break;
			case '*': {

				if (GETCHAR(1) == '=') {
					_make_token(TK_OP_ASSIGN_MUL);
					INCPOS(1);
				} else {
					_make_token(TK_OP_MUL);
				}
			} break;
			case '+': {

				if (GETCHAR(1) == '=') {
					_make_token(TK_OP_ASSIGN_ADD);
					INCPOS(1);
					//}  else if (GETCHAR(1)=='+') {
					//	_make_token(TK_OP_PLUS_PLUS);
					//	INCPOS(1);
				} else {
					_make_token(TK_OP_ADD);
				}

			} break;
			case '-': {

				if (GETCHAR(1) == '=') {
					_make_token(TK_OP_ASSIGN_SUB);
					INCPOS(1);
					//}  else if (GETCHAR(1)=='-') {
					//	_make_token(TK_OP_MINUS_MINUS);
					//	INCPOS(1);
				} else {
					_make_token(TK_OP_SUB);
				}
			} break;
			case '%': {

				if (GETCHAR(1) == '=') {
					_make_token(TK_OP_ASSIGN_MOD);
					INCPOS(1);
				} else {
					_make_token(TK_OP_MOD);
				}
			} break;
			case '@':
				if (CharType(GETCHAR(1)) != '"' && CharType(GETCHAR(1)) != '\'') {
					_make_error("Unexpected '@'");
					return;
				}
				INCPOS(1);
				is_node_path = true;

			case '\'':
			case '"': {

				if (GETCHAR(0) == '\'')
					string_mode = STRING_SINGLE_QUOTE;

				int i = 1;
				if (string_mode == STRING_DOUBLE_QUOTE && GETCHAR(i) == '"' && GETCHAR(i + 1) == '"') {
					i += 2;
					string_mode = STRING_MULTILINE;
				}

				String str;
				while (true) {
					if (CharType(GETCHAR(i)) == 0) {

						_make_error("Unterminated String");
						return;
					} else if (string_mode == STRING_DOUBLE_QUOTE && CharType(GETCHAR(i)) == '"') {
						break;
					} else if (string_mode == STRING_SINGLE_QUOTE && CharType(GETCHAR(i)) == '\'') {
						break;
					} else if (string_mode == STRING_MULTILINE && CharType(GETCHAR(i)) == '\"' && CharType(GETCHAR(i + 1)) == '\"' && CharType(GETCHAR(i + 2)) == '\"') {
						i += 2;
						break;
					} else if (string_mode != STRING_MULTILINE && CharType(GETCHAR(i)) == '\n') {
						_make_error("Unexpected EOL at String.");
						return;
					} else if (CharType(GETCHAR(i)) == 0xFFFF) {
						//string ends here, next will be TK
						i--;
						break;
					} else if (CharType(GETCHAR(i)) == '\\') {
						//escaped characters...
						i++;
						CharType next = GETCHAR(i);
						if (next == 0) {
							_make_error("Unterminated String");
							return;
						}
						CharType res = 0;

						switch (next) {

							case 'a': res = 7; break;
							case 'b': res = 8; break;
							case 't': res = 9; break;
							case 'n': res = 10; break;
							case 'v': res = 11; break;
							case 'f': res = 12; break;
							case 'r': res = 13; break;
							case '\'': res = '\''; break;
							case '\"': res = '\"'; break;
							case '\\': res = '\\'; break;
							case '/':
								res = '/';
								break; //wtf

							case 'u': {
								//hexnumbarh - oct is deprecated
								i += 1;
								for (int j = 0; j < 4; j++) {
									CharType c = GETCHAR(i + j);
									if (c == 0) {
										_make_error("Unterminated String");
										return;
									}
									if (!((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F'))) {

										_make_error("Malformed hex constant in string");
										return;
									}
									CharType v;
									if (c >= '0' && c <= '9') {
										v = c - '0';
									} else if (c >= 'a' && c <= 'f') {
										v = c - 'a';
										v += 10;
									} else if (c >= 'A' && c <= 'F') {
										v = c - 'A';
										v += 10;
									} else {
										ERR_PRINT("BUG");
										v = 0;
									}

									res <<= 4;
									res |= v;
								}
								i += 3;

							} break;
							default: {

								_make_error("Invalid escape sequence");
								return;
							} break;
						}

						str += res;

					} else {
						if (CharType(GETCHAR(i)) == '\n') {
							line++;
							column = 1;
						}

						str += CharType(GETCHAR(i));
					}
					i++;
				}
				INCPOS(i);

				if (is_node_path) {
					_make_constant(NodePath(str));
				} else {
					_make_constant(str);
				}

			} break;
			case 0xFFFF: {
				_make_token(TK_CURSOR);
			} break;
			default: {

				if (_is_number(GETCHAR(0)) || (GETCHAR(0) == '.' && _is_number(GETCHAR(1)))) {
					// parse number
					bool period_found = false;
					bool exponent_found = false;
					bool hexa_found = false;
					bool sign_found = false;

					String str;
					int i = 0;

					while (true) {
						if (GETCHAR(i) == '.') {
							if (period_found || exponent_found) {
								_make_error("Invalid numeric constant at '.'");
								return;
							}
							period_found = true;
						} else if (GETCHAR(i) == 'x') {
							if (hexa_found || str.length() != 1 || !((i == 1 && str[0] == '0') || (i == 2 && str[1] == '0' && str[0] == '-'))) {
								_make_error("Invalid numeric constant at 'x'");
								return;
							}
							hexa_found = true;
						} else if (!hexa_found && GETCHAR(i) == 'e') {
							if (hexa_found || exponent_found) {
								_make_error("Invalid numeric constant at 'e'");
								return;
							}
							exponent_found = true;
						} else if (_is_number(GETCHAR(i))) {
							//all ok
						} else if (hexa_found && _is_hex(GETCHAR(i))) {

						} else if ((GETCHAR(i) == '-' || GETCHAR(i) == '+') && exponent_found) {
							if (sign_found) {
								_make_error("Invalid numeric constant at '-'");
								return;
							}
							sign_found = true;
						} else
							break;

						str += CharType(GETCHAR(i));
						i++;
					}

					if (!(_is_number(str[str.length() - 1]) || (hexa_found && _is_hex(str[str.length() - 1])))) {
						_make_error("Invalid numeric constant: " + str);
						return;
					}

					INCPOS(str.length());
					if (hexa_found) {
						int val = str.hex_to_int();
						_make_constant(val);
					} else if (period_found || exponent_found) {
						real_t val = str.to_double();
						//print_line("*%*%*%*% to convert: "+str+" result: "+rtos(val));
						_make_constant(val);
					} else {
						int val = str.to_int();
						_make_constant(val);
					}

					return;
				}

				if (GETCHAR(0) == '.') {
					//parse period
					_make_token(TK_PERIOD);
					break;
				}

				if (_is_text_char(GETCHAR(0))) {
					// parse identifier
					String str;
					str += CharType(GETCHAR(0));

					int i = 1;
					while (_is_text_char(GETCHAR(i))) {
						str += CharType(GETCHAR(i));
						i++;
					}

					bool identifier = false;

					if (str == "null") {
						_make_constant(Variant());

					} else if (str == "true") {
						_make_constant(true);

					} else if (str == "false") {
						_make_constant(false);
					} else {

						bool found = false;

						struct _bit {
							Variant::Type type;
							const char *text;
						};
						//built in types

						static const _bit type_list[] = {
							//types
							{ Variant::BOOL, "bool" },
							{ Variant::INT, "int" },
							{ Variant::REAL, "float" },
							{ Variant::STRING, "String" },
							{ Variant::VECTOR2, "Vector2" },
							{ Variant::RECT2, "Rect2" },
							{ Variant::MATRIX32, "Matrix32" },
							{ Variant::VECTOR3, "Vector3" },
							{ Variant::_AABB, "AABB" },
							{ Variant::_AABB, "Rect3" },
							{ Variant::PLANE, "Plane" },
							{ Variant::QUAT, "Quat" },
							{ Variant::MATRIX3, "Matrix3" },
							{ Variant::TRANSFORM, "Transform" },
							{ Variant::COLOR, "Color" },
							{ Variant::IMAGE, "Image" },
							{ Variant::_RID, "RID" },
							{ Variant::OBJECT, "Object" },
							{ Variant::INPUT_EVENT, "InputEvent" },
							{ Variant::NODE_PATH, "NodePath" },
							{ Variant::DICTIONARY, "Dictionary" },
							{ Variant::ARRAY, "Array" },
							{ Variant::RAW_ARRAY, "RawArray" },
							{ Variant::INT_ARRAY, "IntArray" },
							{ Variant::REAL_ARRAY, "FloatArray" },
							{ Variant::STRING_ARRAY, "StringArray" },
							{ Variant::VECTOR2_ARRAY, "Vector2Array" },
							{ Variant::VECTOR3_ARRAY, "Vector3Array" },
							{ Variant::COLOR_ARRAY, "ColorArray" },
							{ Variant::VARIANT_MAX, NULL },
						};

						{

							int idx = 0;

							while (type_list[idx].text) {

								if (str == type_list[idx].text) {
									_make_type(type_list[idx].type);
									found = true;
									break;
								}
								idx++;
							}
						}

						if (!found) {

							//built in func?

							for (int i = 0; i < GDFunctions::FUNC_MAX; i++) {

								if (str == GDFunctions::get_func_name(GDFunctions::Function(i))) {

									_make_built_in_func(GDFunctions::Function(i));
									found = true;
									break;
								}
							}

							//keywor
						}

						if (!found) {

							struct _kws {
								Token token;
								const char *text;
							};

							static const _kws keyword_list[] = {
								//ops
								{ TK_OP_IN, "in" },
								{ TK_OP_NOT, "not" },
								{ TK_OP_OR, "or" },
								{ TK_OP_AND, "and" },
								//func
								{ TK_PR_FUNCTION, "func" },
								{ TK_PR_CLASS, "class" },
								{ TK_PR_EXTENDS, "extends" },
								{ TK_PR_ONREADY, "onready" },
								{ TK_PR_TOOL, "tool" },
								{ TK_PR_STATIC, "static" },
								{ TK_PR_EXPORT, "export" },
								{ TK_PR_SETGET, "setget" },
								{ TK_PR_VAR, "var" },
								{ TK_PR_PRELOAD, "preload" },
								{ TK_PR_ASSERT, "assert" },
								{ TK_PR_YIELD, "yield" },
								{ TK_PR_SIGNAL, "signal" },
								{ TK_PR_BREAKPOINT, "breakpoint" },
								{ TK_PR_CONST, "const" },
								{ TK_PR_ENUM, "enum" },
								//controlflow
								{ TK_CF_IF, "if" },
								{ TK_CF_ELIF, "elif" },
								{ TK_CF_ELSE, "else" },
								{ TK_CF_FOR, "for" },
								{ TK_CF_WHILE, "while" },
								{ TK_CF_DO, "do" },
								{ TK_CF_SWITCH, "switch" },
								{ TK_CF_CASE, "case" },
								{ TK_CF_BREAK, "break" },
								{ TK_CF_CONTINUE, "continue" },
								{ TK_CF_RETURN, "return" },
								{ TK_CF_PASS, "pass" },
								{ TK_SELF, "self" },
								{ TK_CONST_PI, "PI" },
								{ TK_ERROR, NULL }
							};

							int idx = 0;
							found = false;

							while (keyword_list[idx].text) {

								if (str == keyword_list[idx].text) {
									_make_token(keyword_list[idx].token);
									found = true;
									break;
								}
								idx++;
							}
						}

						if (!found)
							identifier = true;
					}

					if (identifier) {
						_make_identifier(str);
					}
					INCPOS(str.length());
					return;
				}

				_make_error("Unknown character");
				return;

			} break;
		}

		INCPOS(1);
		break;
	}
}

void GDTokenizerText::set_code(const String &p_code) {

	code = p_code;
	len = p_code.length();
	if (len) {
		_code = &code[0];
	} else {
		_code = NULL;
	}
	code_pos = 0;
	line = 1; //it is stand-ar-ized that lines begin in 1 in code..
	column = 1; //the same holds for columns
	tk_rb_pos = 0;
	error_flag = false;
	last_error = "";
	for (int i = 0; i < MAX_LOOKAHEAD + 1; i++)
		_advance();
}

GDTokenizerText::Token GDTokenizerText::get_token(int p_offset) const {
	ERR_FAIL_COND_V(p_offset <= -MAX_LOOKAHEAD, TK_ERROR);
	ERR_FAIL_COND_V(p_offset >= MAX_LOOKAHEAD, TK_ERROR);

	int ofs = (TK_RB_SIZE + tk_rb_pos + p_offset - MAX_LOOKAHEAD - 1) % TK_RB_SIZE;
	return tk_rb[ofs].type;
}

int GDTokenizerText::get_token_line(int p_offset) const {
	ERR_FAIL_COND_V(p_offset <= -MAX_LOOKAHEAD, -1);
	ERR_FAIL_COND_V(p_offset >= MAX_LOOKAHEAD, -1);

	int ofs = (TK_RB_SIZE + tk_rb_pos + p_offset - MAX_LOOKAHEAD - 1) % TK_RB_SIZE;
	return tk_rb[ofs].line;
}

int GDTokenizerText::get_token_column(int p_offset) const {
	ERR_FAIL_COND_V(p_offset <= -MAX_LOOKAHEAD, -1);
	ERR_FAIL_COND_V(p_offset >= MAX_LOOKAHEAD, -1);

	int ofs = (TK_RB_SIZE + tk_rb_pos + p_offset - MAX_LOOKAHEAD - 1) % TK_RB_SIZE;
	return tk_rb[ofs].col;
}

const Variant &GDTokenizerText::get_token_constant(int p_offset) const {
	ERR_FAIL_COND_V(p_offset <= -MAX_LOOKAHEAD, tk_rb[0].constant);
	ERR_FAIL_COND_V(p_offset >= MAX_LOOKAHEAD, tk_rb[0].constant);

	int ofs = (TK_RB_SIZE + tk_rb_pos + p_offset - MAX_LOOKAHEAD - 1) % TK_RB_SIZE;
	ERR_FAIL_COND_V(tk_rb[ofs].type != TK_CONSTANT, tk_rb[0].constant);
	return tk_rb[ofs].constant;
}
StringName GDTokenizerText::get_token_identifier(int p_offset) const {

	ERR_FAIL_COND_V(p_offset <= -MAX_LOOKAHEAD, StringName());
	ERR_FAIL_COND_V(p_offset >= MAX_LOOKAHEAD, StringName());

	int ofs = (TK_RB_SIZE + tk_rb_pos + p_offset - MAX_LOOKAHEAD - 1) % TK_RB_SIZE;
	ERR_FAIL_COND_V(tk_rb[ofs].type != TK_IDENTIFIER, StringName());
	return tk_rb[ofs].identifier;
}

GDFunctions::Function GDTokenizerText::get_token_built_in_func(int p_offset) const {

	ERR_FAIL_COND_V(p_offset <= -MAX_LOOKAHEAD, GDFunctions::FUNC_MAX);
	ERR_FAIL_COND_V(p_offset >= MAX_LOOKAHEAD, GDFunctions::FUNC_MAX);

	int ofs = (TK_RB_SIZE + tk_rb_pos + p_offset - MAX_LOOKAHEAD - 1) % TK_RB_SIZE;
	ERR_FAIL_COND_V(tk_rb[ofs].type != TK_BUILT_IN_FUNC, GDFunctions::FUNC_MAX);
	return tk_rb[ofs].func;
}

Variant::Type GDTokenizerText::get_token_type(int p_offset) const {

	ERR_FAIL_COND_V(p_offset <= -MAX_LOOKAHEAD, Variant::NIL);
	ERR_FAIL_COND_V(p_offset >= MAX_LOOKAHEAD, Variant::NIL);

	int ofs = (TK_RB_SIZE + tk_rb_pos + p_offset - MAX_LOOKAHEAD - 1) % TK_RB_SIZE;
	ERR_FAIL_COND_V(tk_rb[ofs].type != TK_BUILT_IN_TYPE, Variant::NIL);
	return tk_rb[ofs].vtype;
}

int GDTokenizerText::get_token_line_indent(int p_offset) const {

	ERR_FAIL_COND_V(p_offset <= -MAX_LOOKAHEAD, 0);
	ERR_FAIL_COND_V(p_offset >= MAX_LOOKAHEAD, 0);

	int ofs = (TK_RB_SIZE + tk_rb_pos + p_offset - MAX_LOOKAHEAD - 1) % TK_RB_SIZE;
	ERR_FAIL_COND_V(tk_rb[ofs].type != TK_NEWLINE, 0);
	return tk_rb[ofs].constant;
}

String GDTokenizerText::get_token_error(int p_offset) const {

	ERR_FAIL_COND_V(p_offset <= -MAX_LOOKAHEAD, String());
	ERR_FAIL_COND_V(p_offset >= MAX_LOOKAHEAD, String());

	int ofs = (TK_RB_SIZE + tk_rb_pos + p_offset - MAX_LOOKAHEAD - 1) % TK_RB_SIZE;
	ERR_FAIL_COND_V(tk_rb[ofs].type != TK_ERROR, String());
	return tk_rb[ofs].constant;
}

void GDTokenizerText::advance(int p_amount) {

	ERR_FAIL_COND(p_amount <= 0);
	for (int i = 0; i < p_amount; i++)
		_advance();
}

//////////////////////////////////////////////////////////////////////////////////////////////////////

#define BYTECODE_VERSION 10

Error GDTokenizerBuffer::set_code_buffer(const Vector<uint8_t> &p_buffer) {

	const uint8_t *buf = p_buffer.ptr();
	int total_len = p_buffer.size();
	ERR_FAIL_COND_V(p_buffer.size() < 24 || p_buffer[0] != 'G' || p_buffer[1] != 'D' || p_buffer[2] != 'S' || p_buffer[3] != 'C', ERR_INVALID_DATA);

	int version = decode_uint32(&buf[4]);
	if (version > BYTECODE_VERSION) {
		ERR_EXPLAIN("Bytecode is too New! Please use a newer engine version.");
		ERR_FAIL_COND_V(version > BYTECODE_VERSION, ERR_INVALID_DATA);
	}
	int identifier_count = decode_uint32(&buf[8]);
	int constant_count = decode_uint32(&buf[12]);
	int line_count = decode_uint32(&buf[16]);
	int token_count = decode_uint32(&buf[20]);

	const uint8_t *b = buf;

	b = &buf[24];
	total_len -= 24;

	identifiers.resize(identifier_count);
	for (int i = 0; i < identifier_count; i++) {

		int len = decode_uint32(b);
		ERR_FAIL_COND_V(len > total_len, ERR_INVALID_DATA);
		b += 4;
		Vector<uint8_t> cs;
		cs.resize(len);
		for (int j = 0; j < len; j++) {
			cs[j] = b[j] ^ 0xb6;
		}

		cs[cs.size() - 1] = 0;
		String s;
		s.parse_utf8((const char *)cs.ptr());
		b += len;
		total_len -= len + 4;
		identifiers[i] = s;
	}

	constants.resize(constant_count);
	for (int i = 0; i < constant_count; i++) {

		Variant v;
		int len;
		Error err = decode_variant(v, b, total_len, &len);
		if (err)
			return err;
		b += len;
		total_len -= len;
		constants[i] = v;
	}

	ERR_FAIL_COND_V(line_count * 8 > total_len, ERR_INVALID_DATA);

	for (int i = 0; i < line_count; i++) {

		uint32_t token = decode_uint32(b);
		b += 4;
		uint32_t linecol = decode_uint32(b);
		b += 4;

		lines.insert(token, linecol);
		total_len -= 8;
	}

	tokens.resize(token_count);

	for (int i = 0; i < token_count; i++) {

		ERR_FAIL_COND_V(total_len < 1, ERR_INVALID_DATA);

		if ((*b) & TOKEN_BYTE_MASK) { //little endian always
			ERR_FAIL_COND_V(total_len < 4, ERR_INVALID_DATA);

			tokens[i] = decode_uint32(b) & ~TOKEN_BYTE_MASK;
			b += 4;
		} else {
			tokens[i] = *b;
			b += 1;
			total_len--;
		}
	}

	token = 0;

	return OK;
}

Vector<uint8_t> GDTokenizerBuffer::parse_code_string(const String &p_code) {

	Vector<uint8_t> buf;

	Map<StringName, int> identifier_map;
	HashMap<Variant, int, VariantHasher, VariantComparator> constant_map;
	Map<uint32_t, int> line_map;
	Vector<uint32_t> token_array;

	GDTokenizerText tt;
	tt.set_code(p_code);
	int line = -1;

	while (true) {

		if (tt.get_token_line() != line) {

			line = tt.get_token_line();
			line_map[line] = token_array.size();
		}

		uint32_t token = tt.get_token();
		switch (tt.get_token()) {

			case TK_IDENTIFIER: {
				StringName id = tt.get_token_identifier();
				if (!identifier_map.has(id)) {
					int idx = identifier_map.size();
					identifier_map[id] = idx;
				}
				token |= identifier_map[id] << TOKEN_BITS;
			} break;
			case TK_CONSTANT: {

				Variant c = tt.get_token_constant();
				if (!constant_map.has(c)) {
					int idx = constant_map.size();
					constant_map[c] = idx;
				}
				token |= constant_map[c] << TOKEN_BITS;
			} break;
			case TK_BUILT_IN_TYPE: {

				token |= tt.get_token_type() << TOKEN_BITS;
			} break;
			case TK_BUILT_IN_FUNC: {

				token |= tt.get_token_built_in_func() << TOKEN_BITS;

			} break;
			case TK_NEWLINE: {

				token |= tt.get_token_line_indent() << TOKEN_BITS;
			} break;
			case TK_ERROR: {

				ERR_FAIL_V(Vector<uint8_t>());
			} break;
			default: {
			}
		};

		token_array.push_back(token);

		if (tt.get_token() == TK_EOF)
			break;
		tt.advance();
	}

	//reverse maps

	Map<int, StringName> rev_identifier_map;
	for (Map<StringName, int>::Element *E = identifier_map.front(); E; E = E->next()) {
		rev_identifier_map[E->get()] = E->key();
	}

	Map<int, Variant> rev_constant_map;
	const Variant *K = NULL;
	while ((K = constant_map.next(K))) {
		rev_constant_map[constant_map[*K]] = *K;
	}

	Map<int, uint32_t> rev_line_map;
	for (Map<uint32_t, int>::Element *E = line_map.front(); E; E = E->next()) {
		rev_line_map[E->get()] = E->key();
	}

	//save header
	buf.resize(24);
	buf[0] = 'G';
	buf[1] = 'D';
	buf[2] = 'S';
	buf[3] = 'C';
	encode_uint32(BYTECODE_VERSION, &buf[4]);
	encode_uint32(identifier_map.size(), &buf[8]);
	encode_uint32(constant_map.size(), &buf[12]);
	encode_uint32(line_map.size(), &buf[16]);
	encode_uint32(token_array.size(), &buf[20]);

	//save identifiers

	for (Map<int, StringName>::Element *E = rev_identifier_map.front(); E; E = E->next()) {

		CharString cs = String(E->get()).utf8();
		int len = cs.length() + 1;
		int extra = 4 - (len % 4);
		if (extra == 4)
			extra = 0;

		uint8_t ibuf[4];
		encode_uint32(len + extra, ibuf);
		for (int i = 0; i < 4; i++) {
			buf.push_back(ibuf[i]);
		}
		for (int i = 0; i < len; i++) {
			buf.push_back(cs[i] ^ 0xb6);
		}
		for (int i = 0; i < extra; i++) {
			buf.push_back(0 ^ 0xb6);
		}
	}

	for (Map<int, Variant>::Element *E = rev_constant_map.front(); E; E = E->next()) {

		int len;
		Error err = encode_variant(E->get(), NULL, len);
		ERR_FAIL_COND_V(err != OK, Vector<uint8_t>());
		int pos = buf.size();
		buf.resize(pos + len);
		encode_variant(E->get(), &buf[pos], len);
	}

	for (Map<int, uint32_t>::Element *E = rev_line_map.front(); E; E = E->next()) {

		uint8_t ibuf[8];
		encode_uint32(E->key(), &ibuf[0]);
		encode_uint32(E->get(), &ibuf[4]);
		for (int i = 0; i < 8; i++)
			buf.push_back(ibuf[i]);
	}

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

		uint32_t token = token_array[i];

		if (token & ~TOKEN_MASK) {
			uint8_t buf4[4];
			encode_uint32(token_array[i] | TOKEN_BYTE_MASK, &buf4[0]);
			for (int j = 0; j < 4; j++) {
				buf.push_back(buf4[j]);
			}
		} else {
			buf.push_back(token);
		}
	}

	return buf;
}

GDTokenizerBuffer::Token GDTokenizerBuffer::get_token(int p_offset) const {

	int offset = token + p_offset;

	if (offset < 0 || offset >= tokens.size())
		return TK_EOF;

	return GDTokenizerBuffer::Token(tokens[offset] & TOKEN_MASK);
}

StringName GDTokenizerBuffer::get_token_identifier(int p_offset) const {

	int offset = token + p_offset;

	ERR_FAIL_INDEX_V(offset, tokens.size(), StringName());
	uint32_t identifier = tokens[offset] >> TOKEN_BITS;
	ERR_FAIL_INDEX_V(identifier, identifiers.size(), StringName());

	return identifiers[identifier];
}

GDFunctions::Function GDTokenizerBuffer::get_token_built_in_func(int p_offset) const {

	int offset = token + p_offset;
	ERR_FAIL_INDEX_V(offset, tokens.size(), GDFunctions::FUNC_MAX);
	return GDFunctions::Function(tokens[offset] >> TOKEN_BITS);
}

Variant::Type GDTokenizerBuffer::get_token_type(int p_offset) const {

	int offset = token + p_offset;
	ERR_FAIL_INDEX_V(offset, tokens.size(), Variant::NIL);

	return Variant::Type(tokens[offset] >> TOKEN_BITS);
}

int GDTokenizerBuffer::get_token_line(int p_offset) const {

	int offset = token + p_offset;
	int pos = lines.find_nearest(offset);

	if (pos < 0)
		return -1;
	if (pos >= lines.size())
		pos = lines.size() - 1;

	uint32_t l = lines.getv(pos);
	return l & TOKEN_LINE_MASK;
}
int GDTokenizerBuffer::get_token_column(int p_offset) const {

	int offset = token + p_offset;
	int pos = lines.find_nearest(offset);
	if (pos < 0)
		return -1;
	if (pos >= lines.size())
		pos = lines.size() - 1;

	uint32_t l = lines.getv(pos);
	return l >> TOKEN_LINE_BITS;
}
int GDTokenizerBuffer::get_token_line_indent(int p_offset) const {

	int offset = token + p_offset;
	ERR_FAIL_INDEX_V(offset, tokens.size(), 0);
	return tokens[offset] >> TOKEN_BITS;
}
const Variant &GDTokenizerBuffer::get_token_constant(int p_offset) const {

	int offset = token + p_offset;
	ERR_FAIL_INDEX_V(offset, tokens.size(), nil);
	uint32_t constant = tokens[offset] >> TOKEN_BITS;
	ERR_FAIL_INDEX_V(constant, constants.size(), nil);
	return constants[constant];
}
String GDTokenizerBuffer::get_token_error(int p_offset) const {

	ERR_FAIL_V(String());
}

void GDTokenizerBuffer::advance(int p_amount) {

	ERR_FAIL_INDEX(p_amount + token, tokens.size());
	token += p_amount;
}
GDTokenizerBuffer::GDTokenizerBuffer() {

	token = 0;
}