pdfjs-dist
Version:
Generic build of Mozilla's PDF.js library.
311 lines (310 loc) • 8.23 kB
JavaScript
/**
* @licstart The following is the entire license notice for the
* JavaScript code in this page
*
* Copyright 2022 Mozilla Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* @licend The above is the entire license notice for the
* JavaScript code in this page
*/
"use strict";
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.Token = exports.TOKEN = exports.Lexer = void 0;
const KEYWORDS = new Set(["and", "break", "continue", "do", "downto", "else", "elseif", "end", "endfor", "endfunc", "endif", "endwhile", "eq", "exit", "for", "foreach", "func", "ge", "gt", "if", "in", "infinity", "le", "lt", "nan", "ne", "not", "null", "or", "return", "step", "then", "this", "throw", "upto", "var", "while"]);
const TOKEN = {
and: 0,
divide: 1,
dot: 2,
dotDot: 3,
dotHash: 4,
dotStar: 5,
eq: 6,
ge: 7,
gt: 8,
le: 9,
leftBracket: 10,
leftParen: 11,
lt: 12,
minus: 13,
ne: 14,
not: 15,
null: 16,
number: 17,
or: 18,
plus: 19,
rightBracket: 20,
rightParen: 21,
string: 22,
this: 23,
times: 24,
identifier: 25,
break: 26,
continue: 27,
do: 28,
for: 29,
foreach: 30,
func: 31,
if: 32,
var: 33,
while: 34,
assign: 35,
comma: 36,
downto: 37,
else: 38,
elseif: 39,
end: 40,
endif: 41,
endfor: 42,
endfunc: 43,
endwhile: 44,
eof: 45,
exit: 46,
in: 47,
infinity: 48,
nan: 49,
return: 50,
step: 51,
then: 52,
throw: 53,
upto: 54
};
exports.TOKEN = TOKEN;
const hexPattern = /^[uU]([0-9a-fA-F]{4,8})/;
const numberPattern = /^\d*(?:\.\d*)?(?:[Ee][+-]?\d+)?/;
const dotNumberPattern = /^\d*(?:[Ee][+-]?\d+)?/;
const eolPattern = /[\r\n]+/;
const identifierPattern = new RegExp("^[\\p{L}_$!][\\p{L}\\p{N}_$]*", "u");
class Token {
constructor(id, value = null) {
this.id = id;
this.value = value;
}
}
exports.Token = Token;
const Singletons = function () {
const obj = Object.create(null);
const nonSingleton = new Set(["identifier", "string", "number", "nan", "infinity"]);
for (const [name, id] of Object.entries(TOKEN)) {
if (!nonSingleton.has(name)) {
obj[name] = new Token(id);
}
}
obj.nan = new Token(TOKEN.number, NaN);
obj.infinity = new Token(TOKEN.number, Infinity);
return obj;
}();
class Lexer {
constructor(data) {
this.data = data;
this.pos = 0;
this.len = data.length;
this.strBuf = [];
}
skipUntilEOL() {
const match = this.data.slice(this.pos).match(eolPattern);
if (match) {
this.pos += match.index + match[0].length;
} else {
this.pos = this.len;
}
}
getIdentifier() {
this.pos--;
const match = this.data.slice(this.pos).match(identifierPattern);
if (!match) {
throw new Error(`Invalid token in FormCalc expression at position ${this.pos}.`);
}
const identifier = this.data.slice(this.pos, this.pos + match[0].length);
this.pos += match[0].length;
const lower = identifier.toLowerCase();
if (!KEYWORDS.has(lower)) {
return new Token(TOKEN.identifier, identifier);
}
return Singletons[lower];
}
getString() {
const str = this.strBuf;
const data = this.data;
let start = this.pos;
while (this.pos < this.len) {
const char = data.charCodeAt(this.pos++);
if (char === 0x22) {
if (data.charCodeAt(this.pos) === 0x22) {
str.push(data.slice(start, this.pos++));
start = this.pos;
continue;
}
break;
}
if (char === 0x5c) {
const match = data.substring(this.pos, this.pos + 10).match(hexPattern);
if (!match) {
continue;
}
str.push(data.slice(start, this.pos - 1));
const code = match[1];
if (code.length === 4) {
str.push(String.fromCharCode(parseInt(code, 16)));
start = this.pos += 5;
} else if (code.length !== 8) {
str.push(String.fromCharCode(parseInt(code.slice(0, 4), 16)));
start = this.pos += 5;
} else {
str.push(String.fromCharCode(parseInt(code, 16)));
start = this.pos += 9;
}
}
}
const lastChunk = data.slice(start, this.pos - 1);
if (str.length === 0) {
return new Token(TOKEN.string, lastChunk);
}
str.push(lastChunk);
const string = str.join("");
str.length = 0;
return new Token(TOKEN.string, string);
}
getNumber(first) {
const match = this.data.substring(this.pos).match(numberPattern);
if (!match[0]) {
return new Token(TOKEN.number, first - 0x30);
}
const number = parseFloat(this.data.substring(this.pos - 1, this.pos + match[0].length));
this.pos += match[0].length;
return new Token(TOKEN.number, number);
}
getCompOperator(alt1, alt2) {
if (this.data.charCodeAt(this.pos) === 0x3d) {
this.pos++;
return alt1;
}
return alt2;
}
getLower() {
const char = this.data.charCodeAt(this.pos);
if (char === 0x3d) {
this.pos++;
return Singletons.le;
}
if (char === 0x3e) {
this.pos++;
return Singletons.ne;
}
return Singletons.lt;
}
getSlash() {
if (this.data.charCodeAt(this.pos) === 0x2f) {
this.skipUntilEOL();
return false;
}
return true;
}
getDot() {
const char = this.data.charCodeAt(this.pos);
if (char === 0x2e) {
this.pos++;
return Singletons.dotDot;
}
if (char === 0x2a) {
this.pos++;
return Singletons.dotStar;
}
if (char === 0x23) {
this.pos++;
return Singletons.dotHash;
}
if (0x30 <= char && char <= 0x39) {
this.pos++;
const match = this.data.substring(this.pos).match(dotNumberPattern);
if (!match) {
return new Token(TOKEN.number, (char - 0x30) / 10);
}
const end = this.pos + match[0].length;
const number = parseFloat(this.data.substring(this.pos - 2, end));
this.pos = end;
return new Token(TOKEN.number, number);
}
return Singletons.dot;
}
next() {
while (this.pos < this.len) {
const char = this.data.charCodeAt(this.pos++);
switch (char) {
case 0x09:
case 0x0a:
case 0x0b:
case 0x0c:
case 0x0d:
case 0x20:
break;
case 0x22:
return this.getString();
case 0x26:
return Singletons.and;
case 0x28:
return Singletons.leftParen;
case 0x29:
return Singletons.rightParen;
case 0x2a:
return Singletons.times;
case 0x2b:
return Singletons.plus;
case 0x2c:
return Singletons.comma;
case 0x2d:
return Singletons.minus;
case 0x2e:
return this.getDot();
case 0x2f:
if (this.getSlash()) {
return Singletons.divide;
}
break;
case 0x30:
case 0x31:
case 0x32:
case 0x33:
case 0x34:
case 0x35:
case 0x36:
case 0x37:
case 0x38:
case 0x39:
return this.getNumber(char);
case 0x3b:
this.skipUntilEOL();
break;
case 0x3c:
return this.getLower();
case 0x3d:
return this.getCompOperator(Singletons.eq, Singletons.assign);
case 0x3e:
return this.getCompOperator(Singletons.ge, Singletons.gt);
case 0x5b:
return Singletons.leftBracket;
case 0x5d:
return Singletons.rightBracket;
case 0x7c:
return Singletons.or;
default:
return this.getIdentifier();
}
}
return Singletons.eof;
}
}
exports.Lexer = Lexer;