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721 lines (614 loc) · 18.7 KB
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/**
* @license
* Copyright Google Inc. All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import * as chars from '../chars';
export enum CssTokenType {
EOF,
String,
Comment,
Identifier,
Number,
IdentifierOrNumber,
AtKeyword,
Character,
Whitespace,
Invalid
}
export enum CssLexerMode {
ALL,
ALL_TRACK_WS,
SELECTOR,
PSEUDO_SELECTOR,
PSEUDO_SELECTOR_WITH_ARGUMENTS,
ATTRIBUTE_SELECTOR,
AT_RULE_QUERY,
MEDIA_QUERY,
BLOCK,
KEYFRAME_BLOCK,
STYLE_BLOCK,
STYLE_VALUE,
STYLE_VALUE_FUNCTION,
STYLE_CALC_FUNCTION
}
export class LexedCssResult {
constructor(public error: Error|null, public token: CssToken) {}
}
export function generateErrorMessage(
input: string, message: string, errorValue: string, index: number, row: number,
column: number): string {
return `${message} at column ${row}:${column} in expression [` +
findProblemCode(input, errorValue, index, column) + ']';
}
export function findProblemCode(
input: string, errorValue: string, index: number, column: number): string {
let endOfProblemLine = index;
let current = charCode(input, index);
while (current > 0 && !isNewline(current)) {
current = charCode(input, ++endOfProblemLine);
}
const choppedString = input.substring(0, endOfProblemLine);
let pointerPadding = '';
for (let i = 0; i < column; i++) {
pointerPadding += ' ';
}
let pointerString = '';
for (let i = 0; i < errorValue.length; i++) {
pointerString += '^';
}
return choppedString + '\n' + pointerPadding + pointerString + '\n';
}
export class CssToken {
numValue: number;
constructor(
public index: number, public column: number, public line: number, public type: CssTokenType,
public strValue: string) {
this.numValue = charCode(strValue, 0);
}
}
export class CssLexer {
scan(text: string, trackComments: boolean = false): CssScanner {
return new CssScanner(text, trackComments);
}
}
export function cssScannerError(token: CssToken, message: string): Error {
const error = Error('CssParseError: ' + message);
(error as any)[ERROR_RAW_MESSAGE] = message;
(error as any)[ERROR_TOKEN] = token;
return error;
}
const ERROR_TOKEN = 'ngToken';
const ERROR_RAW_MESSAGE = 'ngRawMessage';
export function getRawMessage(error: Error): string {
return (error as any)[ERROR_RAW_MESSAGE];
}
export function getToken(error: Error): CssToken {
return (error as any)[ERROR_TOKEN];
}
function _trackWhitespace(mode: CssLexerMode) {
switch (mode) {
case CssLexerMode.SELECTOR:
case CssLexerMode.PSEUDO_SELECTOR:
case CssLexerMode.ALL_TRACK_WS:
case CssLexerMode.STYLE_VALUE:
return true;
default:
return false;
}
}
export class CssScanner {
peek: number;
peekPeek: number;
length: number = 0;
index: number = -1;
column: number = -1;
line: number = 0;
/** @internal */
_currentMode: CssLexerMode = CssLexerMode.BLOCK;
/** @internal */
_currentError: Error|null = null;
constructor(public input: string, private _trackComments: boolean = false) {
this.length = this.input.length;
this.peekPeek = this.peekAt(0);
this.advance();
}
getMode(): CssLexerMode { return this._currentMode; }
setMode(mode: CssLexerMode) {
if (this._currentMode != mode) {
if (_trackWhitespace(this._currentMode) && !_trackWhitespace(mode)) {
this.consumeWhitespace();
}
this._currentMode = mode;
}
}
advance(): void {
if (isNewline(this.peek)) {
this.column = 0;
this.line++;
} else {
this.column++;
}
this.index++;
this.peek = this.peekPeek;
this.peekPeek = this.peekAt(this.index + 1);
}
peekAt(index: number): number {
return index >= this.length ? chars.$EOF : this.input.charCodeAt(index);
}
consumeEmptyStatements(): void {
this.consumeWhitespace();
while (this.peek == chars.$SEMICOLON) {
this.advance();
this.consumeWhitespace();
}
}
consumeWhitespace(): void {
while (chars.isWhitespace(this.peek) || isNewline(this.peek)) {
this.advance();
if (!this._trackComments && isCommentStart(this.peek, this.peekPeek)) {
this.advance(); // /
this.advance(); // *
while (!isCommentEnd(this.peek, this.peekPeek)) {
if (this.peek == chars.$EOF) {
this.error('Unterminated comment');
}
this.advance();
}
this.advance(); // *
this.advance(); // /
}
}
}
consume(type: CssTokenType, value: string|null = null): LexedCssResult {
const mode = this._currentMode;
this.setMode(_trackWhitespace(mode) ? CssLexerMode.ALL_TRACK_WS : CssLexerMode.ALL);
const previousIndex = this.index;
const previousLine = this.line;
const previousColumn = this.column;
let next: CssToken = undefined !;
const output = this.scan();
if (output != null) {
// just incase the inner scan method returned an error
if (output.error != null) {
this.setMode(mode);
return output;
}
next = output.token;
}
if (next == null) {
next = new CssToken(this.index, this.column, this.line, CssTokenType.EOF, 'end of file');
}
let isMatchingType: boolean = false;
if (type == CssTokenType.IdentifierOrNumber) {
// TODO (matsko): implement array traversal for lookup here
isMatchingType = next.type == CssTokenType.Number || next.type == CssTokenType.Identifier;
} else {
isMatchingType = next.type == type;
}
// before throwing the error we need to bring back the former
// mode so that the parser can recover...
this.setMode(mode);
let error: Error|null = null;
if (!isMatchingType || (value != null && value != next.strValue)) {
let errorMessage =
CssTokenType[next.type] + ' does not match expected ' + CssTokenType[type] + ' value';
if (value != null) {
errorMessage += ' ("' + next.strValue + '" should match "' + value + '")';
}
error = cssScannerError(
next, generateErrorMessage(
this.input, errorMessage, next.strValue, previousIndex, previousLine,
previousColumn));
}
return new LexedCssResult(error, next);
}
scan(): LexedCssResult|null {
const trackWS = _trackWhitespace(this._currentMode);
if (this.index == 0 && !trackWS) { // first scan
this.consumeWhitespace();
}
const token = this._scan();
if (token == null) return null;
const error = this._currentError !;
this._currentError = null;
if (!trackWS) {
this.consumeWhitespace();
}
return new LexedCssResult(error, token);
}
/** @internal */
_scan(): CssToken|null {
let peek = this.peek;
let peekPeek = this.peekPeek;
if (peek == chars.$EOF) return null;
if (isCommentStart(peek, peekPeek)) {
// even if comments are not tracked we still lex the
// comment so we can move the pointer forward
const commentToken = this.scanComment();
if (this._trackComments) {
return commentToken;
}
}
if (_trackWhitespace(this._currentMode) && (chars.isWhitespace(peek) || isNewline(peek))) {
return this.scanWhitespace();
}
peek = this.peek;
peekPeek = this.peekPeek;
if (peek == chars.$EOF) return null;
if (isStringStart(peek, peekPeek)) {
return this.scanString();
}
// something like url(cool)
if (this._currentMode == CssLexerMode.STYLE_VALUE_FUNCTION) {
return this.scanCssValueFunction();
}
const isModifier = peek == chars.$PLUS || peek == chars.$MINUS;
const digitA = isModifier ? false : chars.isDigit(peek);
const digitB = chars.isDigit(peekPeek);
if (digitA || (isModifier && (peekPeek == chars.$PERIOD || digitB)) ||
(peek == chars.$PERIOD && digitB)) {
return this.scanNumber();
}
if (peek == chars.$AT) {
return this.scanAtExpression();
}
if (isIdentifierStart(peek, peekPeek)) {
return this.scanIdentifier();
}
if (isValidCssCharacter(peek, this._currentMode)) {
return this.scanCharacter();
}
return this.error(`Unexpected character [${String.fromCharCode(peek)}]`);
}
scanComment(): CssToken|null {
if (this.assertCondition(
isCommentStart(this.peek, this.peekPeek), 'Expected comment start value')) {
return null;
}
const start = this.index;
const startingColumn = this.column;
const startingLine = this.line;
this.advance(); // /
this.advance(); // *
while (!isCommentEnd(this.peek, this.peekPeek)) {
if (this.peek == chars.$EOF) {
this.error('Unterminated comment');
}
this.advance();
}
this.advance(); // *
this.advance(); // /
const str = this.input.substring(start, this.index);
return new CssToken(start, startingColumn, startingLine, CssTokenType.Comment, str);
}
scanWhitespace(): CssToken {
const start = this.index;
const startingColumn = this.column;
const startingLine = this.line;
while (chars.isWhitespace(this.peek) && this.peek != chars.$EOF) {
this.advance();
}
const str = this.input.substring(start, this.index);
return new CssToken(start, startingColumn, startingLine, CssTokenType.Whitespace, str);
}
scanString(): CssToken|null {
if (this.assertCondition(
isStringStart(this.peek, this.peekPeek), 'Unexpected non-string starting value')) {
return null;
}
const target = this.peek;
const start = this.index;
const startingColumn = this.column;
const startingLine = this.line;
let previous = target;
this.advance();
while (!isCharMatch(target, previous, this.peek)) {
if (this.peek == chars.$EOF || isNewline(this.peek)) {
this.error('Unterminated quote');
}
previous = this.peek;
this.advance();
}
if (this.assertCondition(this.peek == target, 'Unterminated quote')) {
return null;
}
this.advance();
const str = this.input.substring(start, this.index);
return new CssToken(start, startingColumn, startingLine, CssTokenType.String, str);
}
scanNumber(): CssToken {
const start = this.index;
const startingColumn = this.column;
if (this.peek == chars.$PLUS || this.peek == chars.$MINUS) {
this.advance();
}
let periodUsed = false;
while (chars.isDigit(this.peek) || this.peek == chars.$PERIOD) {
if (this.peek == chars.$PERIOD) {
if (periodUsed) {
this.error('Unexpected use of a second period value');
}
periodUsed = true;
}
this.advance();
}
const strValue = this.input.substring(start, this.index);
return new CssToken(start, startingColumn, this.line, CssTokenType.Number, strValue);
}
scanIdentifier(): CssToken|null {
if (this.assertCondition(
isIdentifierStart(this.peek, this.peekPeek), 'Expected identifier starting value')) {
return null;
}
const start = this.index;
const startingColumn = this.column;
while (isIdentifierPart(this.peek)) {
this.advance();
}
const strValue = this.input.substring(start, this.index);
return new CssToken(start, startingColumn, this.line, CssTokenType.Identifier, strValue);
}
scanCssValueFunction(): CssToken {
const start = this.index;
const startingColumn = this.column;
let parenBalance = 1;
while (this.peek != chars.$EOF && parenBalance > 0) {
this.advance();
if (this.peek == chars.$LPAREN) {
parenBalance++;
} else if (this.peek == chars.$RPAREN) {
parenBalance--;
}
}
const strValue = this.input.substring(start, this.index);
return new CssToken(start, startingColumn, this.line, CssTokenType.Identifier, strValue);
}
scanCharacter(): CssToken|null {
const start = this.index;
const startingColumn = this.column;
if (this.assertCondition(
isValidCssCharacter(this.peek, this._currentMode),
charStr(this.peek) + ' is not a valid CSS character')) {
return null;
}
const c = this.input.substring(start, start + 1);
this.advance();
return new CssToken(start, startingColumn, this.line, CssTokenType.Character, c);
}
scanAtExpression(): CssToken|null {
if (this.assertCondition(this.peek == chars.$AT, 'Expected @ value')) {
return null;
}
const start = this.index;
const startingColumn = this.column;
this.advance();
if (isIdentifierStart(this.peek, this.peekPeek)) {
const ident = this.scanIdentifier() !;
const strValue = '@' + ident.strValue;
return new CssToken(start, startingColumn, this.line, CssTokenType.AtKeyword, strValue);
} else {
return this.scanCharacter();
}
}
assertCondition(status: boolean, errorMessage: string): boolean {
if (!status) {
this.error(errorMessage);
return true;
}
return false;
}
error(message: string, errorTokenValue: string|null = null, doNotAdvance: boolean = false):
CssToken {
const index: number = this.index;
const column: number = this.column;
const line: number = this.line;
errorTokenValue = errorTokenValue || String.fromCharCode(this.peek);
const invalidToken = new CssToken(index, column, line, CssTokenType.Invalid, errorTokenValue);
const errorMessage =
generateErrorMessage(this.input, message, errorTokenValue, index, line, column);
if (!doNotAdvance) {
this.advance();
}
this._currentError = cssScannerError(invalidToken, errorMessage);
return invalidToken;
}
}
function isCharMatch(target: number, previous: number, code: number): boolean {
return code == target && previous != chars.$BACKSLASH;
}
function isCommentStart(code: number, next: number): boolean {
return code == chars.$SLASH && next == chars.$STAR;
}
function isCommentEnd(code: number, next: number): boolean {
return code == chars.$STAR && next == chars.$SLASH;
}
function isStringStart(code: number, next: number): boolean {
let target = code;
if (target == chars.$BACKSLASH) {
target = next;
}
return target == chars.$DQ || target == chars.$SQ;
}
function isIdentifierStart(code: number, next: number): boolean {
let target = code;
if (target == chars.$MINUS) {
target = next;
}
return chars.isAsciiLetter(target) || target == chars.$BACKSLASH || target == chars.$MINUS ||
target == chars.$_;
}
function isIdentifierPart(target: number): boolean {
return chars.isAsciiLetter(target) || target == chars.$BACKSLASH || target == chars.$MINUS ||
target == chars.$_ || chars.isDigit(target);
}
function isValidPseudoSelectorCharacter(code: number): boolean {
switch (code) {
case chars.$LPAREN:
case chars.$RPAREN:
return true;
default:
return false;
}
}
function isValidKeyframeBlockCharacter(code: number): boolean {
return code == chars.$PERCENT;
}
function isValidAttributeSelectorCharacter(code: number): boolean {
// value^*|$~=something
switch (code) {
case chars.$$:
case chars.$PIPE:
case chars.$CARET:
case chars.$TILDA:
case chars.$STAR:
case chars.$EQ:
return true;
default:
return false;
}
}
function isValidSelectorCharacter(code: number): boolean {
// selector [ key = value ]
// IDENT C IDENT C IDENT C
// #id, .class, *+~>
// tag:PSEUDO
switch (code) {
case chars.$HASH:
case chars.$PERIOD:
case chars.$TILDA:
case chars.$STAR:
case chars.$PLUS:
case chars.$GT:
case chars.$COLON:
case chars.$PIPE:
case chars.$COMMA:
case chars.$LBRACKET:
case chars.$RBRACKET:
return true;
default:
return false;
}
}
function isValidStyleBlockCharacter(code: number): boolean {
// key:value;
// key:calc(something ... )
switch (code) {
case chars.$HASH:
case chars.$SEMICOLON:
case chars.$COLON:
case chars.$PERCENT:
case chars.$SLASH:
case chars.$BACKSLASH:
case chars.$BANG:
case chars.$PERIOD:
case chars.$LPAREN:
case chars.$RPAREN:
return true;
default:
return false;
}
}
function isValidMediaQueryRuleCharacter(code: number): boolean {
// (min-width: 7.5em) and (orientation: landscape)
switch (code) {
case chars.$LPAREN:
case chars.$RPAREN:
case chars.$COLON:
case chars.$PERCENT:
case chars.$PERIOD:
return true;
default:
return false;
}
}
function isValidAtRuleCharacter(code: number): boolean {
// @document url(http://www.w3.org/page?something=on#hash),
switch (code) {
case chars.$LPAREN:
case chars.$RPAREN:
case chars.$COLON:
case chars.$PERCENT:
case chars.$PERIOD:
case chars.$SLASH:
case chars.$BACKSLASH:
case chars.$HASH:
case chars.$EQ:
case chars.$QUESTION:
case chars.$AMPERSAND:
case chars.$STAR:
case chars.$COMMA:
case chars.$MINUS:
case chars.$PLUS:
return true;
default:
return false;
}
}
function isValidStyleFunctionCharacter(code: number): boolean {
switch (code) {
case chars.$PERIOD:
case chars.$MINUS:
case chars.$PLUS:
case chars.$STAR:
case chars.$SLASH:
case chars.$LPAREN:
case chars.$RPAREN:
case chars.$COMMA:
return true;
default:
return false;
}
}
function isValidBlockCharacter(code: number): boolean {
// @something { }
// IDENT
return code == chars.$AT;
}
function isValidCssCharacter(code: number, mode: CssLexerMode): boolean {
switch (mode) {
case CssLexerMode.ALL:
case CssLexerMode.ALL_TRACK_WS:
return true;
case CssLexerMode.SELECTOR:
return isValidSelectorCharacter(code);
case CssLexerMode.PSEUDO_SELECTOR_WITH_ARGUMENTS:
return isValidPseudoSelectorCharacter(code);
case CssLexerMode.ATTRIBUTE_SELECTOR:
return isValidAttributeSelectorCharacter(code);
case CssLexerMode.MEDIA_QUERY:
return isValidMediaQueryRuleCharacter(code);
case CssLexerMode.AT_RULE_QUERY:
return isValidAtRuleCharacter(code);
case CssLexerMode.KEYFRAME_BLOCK:
return isValidKeyframeBlockCharacter(code);
case CssLexerMode.STYLE_BLOCK:
case CssLexerMode.STYLE_VALUE:
return isValidStyleBlockCharacter(code);
case CssLexerMode.STYLE_CALC_FUNCTION:
return isValidStyleFunctionCharacter(code);
case CssLexerMode.BLOCK:
return isValidBlockCharacter(code);
default:
return false;
}
}
function charCode(input: string, index: number): number {
return index >= input.length ? chars.$EOF : input.charCodeAt(index);
}
function charStr(code: number): string {
return String.fromCharCode(code);
}
export function isNewline(code: number): boolean {
switch (code) {
case chars.$FF:
case chars.$CR:
case chars.$LF:
case chars.$VTAB:
return true;
default:
return false;
}
}