474 lines
13 KiB
TypeScript

import {Injectable} from '@angular/core';
import {SetWrapper} from '../../src/facade/collection';
import {NumberWrapper, StringJoiner, StringWrapper, isPresent} from '../../src/facade/lang';
import {BaseException} from '../../src/facade/exceptions';
export enum TokenType {
Character,
Identifier,
Keyword,
String,
Operator,
Number
}
@Injectable()
export class Lexer {
tokenize(text: string): any[] {
var scanner = new _Scanner(text);
var tokens = [];
var token = scanner.scanToken();
while (token != null) {
tokens.push(token);
token = scanner.scanToken();
}
return tokens;
}
}
export class Token {
constructor(public index: number, public type: TokenType, public numValue: number,
public strValue: string) {}
isCharacter(code: number): boolean {
return (this.type == TokenType.Character && this.numValue == code);
}
isNumber(): boolean { return (this.type == TokenType.Number); }
isString(): boolean { return (this.type == TokenType.String); }
isOperator(operater: string): boolean {
return (this.type == TokenType.Operator && this.strValue == operater);
}
isIdentifier(): boolean { return (this.type == TokenType.Identifier); }
isKeyword(): boolean { return (this.type == TokenType.Keyword); }
isKeywordDeprecatedVar(): boolean {
return (this.type == TokenType.Keyword && this.strValue == "var");
}
isKeywordLet(): boolean { return (this.type == TokenType.Keyword && this.strValue == "let"); }
isKeywordNull(): boolean { return (this.type == TokenType.Keyword && this.strValue == "null"); }
isKeywordUndefined(): boolean {
return (this.type == TokenType.Keyword && this.strValue == "undefined");
}
isKeywordTrue(): boolean { return (this.type == TokenType.Keyword && this.strValue == "true"); }
isKeywordFalse(): boolean { return (this.type == TokenType.Keyword && this.strValue == "false"); }
toNumber(): number {
// -1 instead of NULL ok?
return (this.type == TokenType.Number) ? this.numValue : -1;
}
toString(): string {
switch (this.type) {
case TokenType.Character:
case TokenType.Identifier:
case TokenType.Keyword:
case TokenType.Operator:
case TokenType.String:
return this.strValue;
case TokenType.Number:
return this.numValue.toString();
default:
return null;
}
}
}
function newCharacterToken(index: number, code: number): Token {
return new Token(index, TokenType.Character, code, StringWrapper.fromCharCode(code));
}
function newIdentifierToken(index: number, text: string): Token {
return new Token(index, TokenType.Identifier, 0, text);
}
function newKeywordToken(index: number, text: string): Token {
return new Token(index, TokenType.Keyword, 0, text);
}
function newOperatorToken(index: number, text: string): Token {
return new Token(index, TokenType.Operator, 0, text);
}
function newStringToken(index: number, text: string): Token {
return new Token(index, TokenType.String, 0, text);
}
function newNumberToken(index: number, n: number): Token {
return new Token(index, TokenType.Number, n, "");
}
export var EOF: Token = new Token(-1, TokenType.Character, 0, "");
export const $EOF = /*@ts2dart_const*/ 0;
export const $TAB = /*@ts2dart_const*/ 9;
export const $LF = /*@ts2dart_const*/ 10;
export const $VTAB = /*@ts2dart_const*/ 11;
export const $FF = /*@ts2dart_const*/ 12;
export const $CR = /*@ts2dart_const*/ 13;
export const $SPACE = /*@ts2dart_const*/ 32;
export const $BANG = /*@ts2dart_const*/ 33;
export const $DQ = /*@ts2dart_const*/ 34;
export const $HASH = /*@ts2dart_const*/ 35;
export const $$ = /*@ts2dart_const*/ 36;
export const $PERCENT = /*@ts2dart_const*/ 37;
export const $AMPERSAND = /*@ts2dart_const*/ 38;
export const $SQ = /*@ts2dart_const*/ 39;
export const $LPAREN = /*@ts2dart_const*/ 40;
export const $RPAREN = /*@ts2dart_const*/ 41;
export const $STAR = /*@ts2dart_const*/ 42;
export const $PLUS = /*@ts2dart_const*/ 43;
export const $COMMA = /*@ts2dart_const*/ 44;
export const $MINUS = /*@ts2dart_const*/ 45;
export const $PERIOD = /*@ts2dart_const*/ 46;
export const $SLASH = /*@ts2dart_const*/ 47;
export const $COLON = /*@ts2dart_const*/ 58;
export const $SEMICOLON = /*@ts2dart_const*/ 59;
export const $LT = /*@ts2dart_const*/ 60;
export const $EQ = /*@ts2dart_const*/ 61;
export const $GT = /*@ts2dart_const*/ 62;
export const $QUESTION = /*@ts2dart_const*/ 63;
const $0 = /*@ts2dart_const*/ 48;
const $9 = /*@ts2dart_const*/ 57;
const $A = /*@ts2dart_const*/ 65, $E = /*@ts2dart_const*/ 69, $Z = /*@ts2dart_const*/ 90;
export const $LBRACKET = /*@ts2dart_const*/ 91;
export const $BACKSLASH = /*@ts2dart_const*/ 92;
export const $RBRACKET = /*@ts2dart_const*/ 93;
const $CARET = /*@ts2dart_const*/ 94;
const $_ = /*@ts2dart_const*/ 95;
export const $BT = /*@ts2dart_const*/ 96;
const $a = /*@ts2dart_const*/ 97, $e = /*@ts2dart_const*/ 101, $f = /*@ts2dart_const*/ 102;
const $n = /*@ts2dart_const*/ 110, $r = /*@ts2dart_const*/ 114, $t = /*@ts2dart_const*/ 116,
$u = /*@ts2dart_const*/ 117, $v = /*@ts2dart_const*/ 118, $z = /*@ts2dart_const*/ 122;
export const $LBRACE = /*@ts2dart_const*/ 123;
export const $BAR = /*@ts2dart_const*/ 124;
export const $RBRACE = /*@ts2dart_const*/ 125;
const $NBSP = /*@ts2dart_const*/ 160;
export class ScannerError extends BaseException {
constructor(public message) { super(); }
toString(): string { return this.message; }
}
class _Scanner {
length: number;
peek: number = 0;
index: number = -1;
constructor(public input: string) {
this.length = input.length;
this.advance();
}
advance() {
this.peek =
++this.index >= this.length ? $EOF : StringWrapper.charCodeAt(this.input, this.index);
}
scanToken(): Token {
var input = this.input, length = this.length, peek = this.peek, index = this.index;
// Skip whitespace.
while (peek <= $SPACE) {
if (++index >= length) {
peek = $EOF;
break;
} else {
peek = StringWrapper.charCodeAt(input, index);
}
}
this.peek = peek;
this.index = index;
if (index >= length) {
return null;
}
// Handle identifiers and numbers.
if (isIdentifierStart(peek)) return this.scanIdentifier();
if (isDigit(peek)) return this.scanNumber(index);
var start: number = index;
switch (peek) {
case $PERIOD:
this.advance();
return isDigit(this.peek) ? this.scanNumber(start) : newCharacterToken(start, $PERIOD);
case $LPAREN:
case $RPAREN:
case $LBRACE:
case $RBRACE:
case $LBRACKET:
case $RBRACKET:
case $COMMA:
case $COLON:
case $SEMICOLON:
return this.scanCharacter(start, peek);
case $SQ:
case $DQ:
return this.scanString();
case $HASH:
case $PLUS:
case $MINUS:
case $STAR:
case $SLASH:
case $PERCENT:
case $CARET:
return this.scanOperator(start, StringWrapper.fromCharCode(peek));
case $QUESTION:
return this.scanComplexOperator(start, '?', $PERIOD, '.');
case $LT:
case $GT:
return this.scanComplexOperator(start, StringWrapper.fromCharCode(peek), $EQ, '=');
case $BANG:
case $EQ:
return this.scanComplexOperator(start, StringWrapper.fromCharCode(peek), $EQ, '=', $EQ,
'=');
case $AMPERSAND:
return this.scanComplexOperator(start, '&', $AMPERSAND, '&');
case $BAR:
return this.scanComplexOperator(start, '|', $BAR, '|');
case $NBSP:
while (isWhitespace(this.peek)) this.advance();
return this.scanToken();
}
this.error(`Unexpected character [${StringWrapper.fromCharCode(peek)}]`, 0);
return null;
}
scanCharacter(start: number, code: number): Token {
this.advance();
return newCharacterToken(start, code);
}
scanOperator(start: number, str: string): Token {
this.advance();
return newOperatorToken(start, str);
}
/**
* Tokenize a 2/3 char long operator
*
* @param start start index in the expression
* @param one first symbol (always part of the operator)
* @param twoCode code point for the second symbol
* @param two second symbol (part of the operator when the second code point matches)
* @param threeCode code point for the third symbol
* @param three third symbol (part of the operator when provided and matches source expression)
* @returns {Token}
*/
scanComplexOperator(start: number, one: string, twoCode: number, two: string, threeCode?: number,
three?: string): Token {
this.advance();
var str: string = one;
if (this.peek == twoCode) {
this.advance();
str += two;
}
if (isPresent(threeCode) && this.peek == threeCode) {
this.advance();
str += three;
}
return newOperatorToken(start, str);
}
scanIdentifier(): Token {
var start: number = this.index;
this.advance();
while (isIdentifierPart(this.peek)) this.advance();
var str: string = this.input.substring(start, this.index);
if (SetWrapper.has(KEYWORDS, str)) {
return newKeywordToken(start, str);
} else {
return newIdentifierToken(start, str);
}
}
scanNumber(start: number): Token {
var simple: boolean = (this.index === start);
this.advance(); // Skip initial digit.
while (true) {
if (isDigit(this.peek)) {
// Do nothing.
} else if (this.peek == $PERIOD) {
simple = false;
} else if (isExponentStart(this.peek)) {
this.advance();
if (isExponentSign(this.peek)) this.advance();
if (!isDigit(this.peek)) this.error('Invalid exponent', -1);
simple = false;
} else {
break;
}
this.advance();
}
var str: string = this.input.substring(start, this.index);
// TODO
var value: number =
simple ? NumberWrapper.parseIntAutoRadix(str) : NumberWrapper.parseFloat(str);
return newNumberToken(start, value);
}
scanString(): Token {
var start: number = this.index;
var quote: number = this.peek;
this.advance(); // Skip initial quote.
var buffer: StringJoiner;
var marker: number = this.index;
var input: string = this.input;
while (this.peek != quote) {
if (this.peek == $BACKSLASH) {
if (buffer == null) buffer = new StringJoiner();
buffer.add(input.substring(marker, this.index));
this.advance();
var unescapedCode: number;
if (this.peek == $u) {
// 4 character hex code for unicode character.
var hex: string = input.substring(this.index + 1, this.index + 5);
try {
unescapedCode = NumberWrapper.parseInt(hex, 16);
} catch (e) {
this.error(`Invalid unicode escape [\\u${hex}]`, 0);
}
for (var i: number = 0; i < 5; i++) {
this.advance();
}
} else {
unescapedCode = unescape(this.peek);
this.advance();
}
buffer.add(StringWrapper.fromCharCode(unescapedCode));
marker = this.index;
} else if (this.peek == $EOF) {
this.error('Unterminated quote', 0);
} else {
this.advance();
}
}
var last: string = input.substring(marker, this.index);
this.advance(); // Skip terminating quote.
// Compute the unescaped string value.
var unescaped: string = last;
if (buffer != null) {
buffer.add(last);
unescaped = buffer.toString();
}
return newStringToken(start, unescaped);
}
error(message: string, offset: number) {
var position: number = this.index + offset;
throw new ScannerError(
`Lexer Error: ${message} at column ${position} in expression [${this.input}]`);
}
}
function isWhitespace(code: number): boolean {
return (code >= $TAB && code <= $SPACE) || (code == $NBSP);
}
function isIdentifierStart(code: number): boolean {
return ($a <= code && code <= $z) || ($A <= code && code <= $Z) || (code == $_) || (code == $$);
}
export function isIdentifier(input: string): boolean {
if (input.length == 0) return false;
var scanner = new _Scanner(input);
if (!isIdentifierStart(scanner.peek)) return false;
scanner.advance();
while (scanner.peek !== $EOF) {
if (!isIdentifierPart(scanner.peek)) return false;
scanner.advance();
}
return true;
}
function isIdentifierPart(code: number): boolean {
return ($a <= code && code <= $z) || ($A <= code && code <= $Z) || ($0 <= code && code <= $9) ||
(code == $_) || (code == $$);
}
function isDigit(code: number): boolean {
return $0 <= code && code <= $9;
}
function isExponentStart(code: number): boolean {
return code == $e || code == $E;
}
function isExponentSign(code: number): boolean {
return code == $MINUS || code == $PLUS;
}
export function isQuote(code: number): boolean {
return code === $SQ || code === $DQ || code === $BT;
}
function unescape(code: number): number {
switch (code) {
case $n:
return $LF;
case $f:
return $FF;
case $r:
return $CR;
case $t:
return $TAB;
case $v:
return $VTAB;
default:
return code;
}
}
var OPERATORS = SetWrapper.createFromList([
'+',
'-',
'*',
'/',
'%',
'^',
'=',
'==',
'!=',
'===',
'!==',
'<',
'>',
'<=',
'>=',
'&&',
'||',
'&',
'|',
'!',
'?',
'#',
'?.'
]);
var KEYWORDS =
SetWrapper.createFromList(['var', 'let', 'null', 'undefined', 'true', 'false', 'if', 'else']);