From 8d4d7dbf58e79476fee127225f5908e8ef0fccd9 Mon Sep 17 00:00:00 2001 From: Tim van der Meij Date: Sun, 10 Mar 2019 14:27:26 +0100 Subject: [PATCH] Convert the `Lexer` class in `src/core/parser.js` to ES6 syntax --- src/core/parser.js | 814 +++++++++++++++++++++++---------------------- 1 file changed, 409 insertions(+), 405 deletions(-) diff --git a/src/core/parser.js b/src/core/parser.js index f41951e08..b29bcb0e2 100644 --- a/src/core/parser.js +++ b/src/core/parser.js @@ -714,8 +714,40 @@ class Parser { } } -var Lexer = (function LexerClosure() { - function Lexer(stream, knownCommands) { +// A '1' in this array means the character is white space. A '1' or +// '2' means the character ends a name or command. +const specialChars = [ + 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0, // 0x + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 1x + 1, 0, 0, 0, 0, 2, 0, 0, 2, 2, 0, 0, 0, 0, 0, 2, // 2x + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, // 3x + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 4x + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, 0, // 5x + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 6x + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, 0, // 7x + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 8x + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 9x + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // ax + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // bx + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // cx + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // dx + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // ex + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 // fx +]; + +function toHexDigit(ch) { + if (ch >= 0x30 && ch <= 0x39) { // '0'-'9' + return ch & 0x0F; + } + if ((ch >= 0x41 && ch <= 0x46) || (ch >= 0x61 && ch <= 0x66)) { + // 'A'-'F', 'a'-'f' + return (ch & 0x0F) + 9; + } + return -1; +} + +class Lexer { + constructor(stream, knownCommands) { this.stream = stream; this.nextChar(); @@ -738,435 +770,407 @@ var Lexer = (function LexerClosure() { this.beginInlineImagePos = -1; } - // A '1' in this array means the character is white space. A '1' or - // '2' means the character ends a name or command. - var specialChars = [ - 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0, // 0x - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 1x - 1, 0, 0, 0, 0, 2, 0, 0, 2, 2, 0, 0, 0, 0, 0, 2, // 2x - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, // 3x - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 4x - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, 0, // 5x - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 6x - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, 0, // 7x - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 8x - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 9x - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // ax - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // bx - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // cx - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // dx - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // ex - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 // fx - ]; - - function toHexDigit(ch) { - if (ch >= 0x30 && ch <= 0x39) { // '0'-'9' - return ch & 0x0F; - } - if ((ch >= 0x41 && ch <= 0x46) || (ch >= 0x61 && ch <= 0x66)) { - // 'A'-'F', 'a'-'f' - return (ch & 0x0F) + 9; - } - return -1; + nextChar() { + return (this.currentChar = this.stream.getByte()); } - Lexer.prototype = { - nextChar: function Lexer_nextChar() { - return (this.currentChar = this.stream.getByte()); - }, - peekChar: function Lexer_peekChar() { - return this.stream.peekByte(); - }, - getNumber: function Lexer_getNumber() { - var ch = this.currentChar; - var eNotation = false; - var divideBy = 0; // different from 0 if it's a floating point value - var sign = 0; + peekChar() { + return this.stream.peekByte(); + } + + getNumber() { + let ch = this.currentChar; + let eNotation = false; + let divideBy = 0; // Different from 0 if it's a floating point value. + let sign = 0; + + if (ch === 0x2D) { // '-' + sign = -1; + ch = this.nextChar(); if (ch === 0x2D) { // '-' - sign = -1; - ch = this.nextChar(); - - if (ch === 0x2D) { // '-' - // Ignore double negative (this is consistent with Adobe Reader). - ch = this.nextChar(); - } - } else if (ch === 0x2B) { // '+' - sign = 1; + // Ignore double negative (this is consistent with Adobe Reader). ch = this.nextChar(); } - if (ch === 0x0A || ch === 0x0D) { // LF, CR - // Ignore line-breaks (this is consistent with Adobe Reader). - do { - ch = this.nextChar(); - } while (ch === 0x0A || ch === 0x0D); - } - if (ch === 0x2E) { // '.' - divideBy = 10; + } else if (ch === 0x2B) { // '+' + sign = 1; + ch = this.nextChar(); + } + if (ch === 0x0A || ch === 0x0D) { // LF, CR + // Ignore line-breaks (this is consistent with Adobe Reader). + do { ch = this.nextChar(); + } while (ch === 0x0A || ch === 0x0D); + } + if (ch === 0x2E) { // '.' + divideBy = 10; + ch = this.nextChar(); + } + if (ch < 0x30 || ch > 0x39) { // '0' - '9' + if (divideBy === 10 && sign === 0 && + (isSpace(ch) || ch === /* EOF = */ -1)) { + // This is consistent with Adobe Reader (fixes issue9252.pdf). + warn('Lexer.getNumber - treating a single decimal point as zero.'); + return 0; } - if (ch < 0x30 || ch > 0x39) { // '0' - '9' - if (divideBy === 10 && sign === 0 && - (isSpace(ch) || ch === /* EOF = */ -1)) { - // This is consistent with Adobe Reader (fixes issue9252.pdf). - warn('Lexer.getNumber - treating a single decimal point as zero.'); - return 0; - } - throw new FormatError( - `Invalid number: ${String.fromCharCode(ch)} (charCode ${ch})`); - } + throw new FormatError( + `Invalid number: ${String.fromCharCode(ch)} (charCode ${ch})`); + } - sign = sign || 1; - var baseValue = ch - 0x30; // '0' - var powerValue = 0; - var powerValueSign = 1; + sign = sign || 1; + let baseValue = ch - 0x30; // '0' + let powerValue = 0; + let powerValueSign = 1; - while ((ch = this.nextChar()) >= 0) { - if (0x30 <= ch && ch <= 0x39) { // '0' - '9' - var currentDigit = ch - 0x30; // '0' - if (eNotation) { // We are after an 'e' or 'E' - powerValue = powerValue * 10 + currentDigit; - } else { - if (divideBy !== 0) { // We are after a point - divideBy *= 10; - } - baseValue = baseValue * 10 + currentDigit; - } - } else if (ch === 0x2E) { // '.' - if (divideBy === 0) { - divideBy = 1; - } else { - // A number can have only one '.' - break; - } - } else if (ch === 0x2D) { // '-' - // ignore minus signs in the middle of numbers to match - // Adobe's behavior - warn('Badly formatted number'); - } else if (ch === 0x45 || ch === 0x65) { // 'E', 'e' - // 'E' can be either a scientific notation or the beginning of a new - // operator - ch = this.peekChar(); - if (ch === 0x2B || ch === 0x2D) { // '+', '-' - powerValueSign = (ch === 0x2D) ? -1 : 1; - this.nextChar(); // Consume the sign character - } else if (ch < 0x30 || ch > 0x39) { // '0' - '9' - // The 'E' must be the beginning of a new operator - break; - } - eNotation = true; + while ((ch = this.nextChar()) >= 0) { + if (0x30 <= ch && ch <= 0x39) { // '0' - '9' + const currentDigit = ch - 0x30; // '0' + if (eNotation) { // We are after an 'e' or 'E'. + powerValue = powerValue * 10 + currentDigit; } else { - // the last character doesn't belong to us - break; - } - } - - if (divideBy !== 0) { - baseValue /= divideBy; - } - if (eNotation) { - baseValue *= Math.pow(10, powerValueSign * powerValue); - } - return sign * baseValue; - }, - getString: function Lexer_getString() { - var numParen = 1; - var done = false; - var strBuf = this.strBuf; - strBuf.length = 0; - - var ch = this.nextChar(); - while (true) { - var charBuffered = false; - switch (ch | 0) { - case -1: - warn('Unterminated string'); - done = true; - break; - case 0x28: // '(' - ++numParen; - strBuf.push('('); - break; - case 0x29: // ')' - if (--numParen === 0) { - this.nextChar(); // consume strings ')' - done = true; - } else { - strBuf.push(')'); - } - break; - case 0x5C: // '\\' - ch = this.nextChar(); - switch (ch) { - case -1: - warn('Unterminated string'); - done = true; - break; - case 0x6E: // 'n' - strBuf.push('\n'); - break; - case 0x72: // 'r' - strBuf.push('\r'); - break; - case 0x74: // 't' - strBuf.push('\t'); - break; - case 0x62: // 'b' - strBuf.push('\b'); - break; - case 0x66: // 'f' - strBuf.push('\f'); - break; - case 0x5C: // '\' - case 0x28: // '(' - case 0x29: // ')' - strBuf.push(String.fromCharCode(ch)); - break; - case 0x30: case 0x31: case 0x32: case 0x33: // '0'-'3' - case 0x34: case 0x35: case 0x36: case 0x37: // '4'-'7' - var x = ch & 0x0F; - ch = this.nextChar(); - charBuffered = true; - if (ch >= 0x30 && ch <= 0x37) { // '0'-'7' - x = (x << 3) + (ch & 0x0F); - ch = this.nextChar(); - if (ch >= 0x30 && ch <= 0x37) { // '0'-'7' - charBuffered = false; - x = (x << 3) + (ch & 0x0F); - } - } - strBuf.push(String.fromCharCode(x)); - break; - case 0x0D: // CR - if (this.peekChar() === 0x0A) { // LF - this.nextChar(); - } - break; - case 0x0A: // LF - break; - default: - strBuf.push(String.fromCharCode(ch)); - break; - } - break; - default: - strBuf.push(String.fromCharCode(ch)); - break; - } - if (done) { - break; - } - if (!charBuffered) { - ch = this.nextChar(); - } - } - return strBuf.join(''); - }, - getName: function Lexer_getName() { - var ch, previousCh; - var strBuf = this.strBuf; - strBuf.length = 0; - while ((ch = this.nextChar()) >= 0 && !specialChars[ch]) { - if (ch === 0x23) { // '#' - ch = this.nextChar(); - if (specialChars[ch]) { - warn('Lexer_getName: ' + - 'NUMBER SIGN (#) should be followed by a hexadecimal number.'); - strBuf.push('#'); - break; - } - var x = toHexDigit(ch); - if (x !== -1) { - previousCh = ch; - ch = this.nextChar(); - var x2 = toHexDigit(ch); - if (x2 === -1) { - warn('Lexer_getName: Illegal digit (' + - String.fromCharCode(ch) + ') in hexadecimal number.'); - strBuf.push('#', String.fromCharCode(previousCh)); - if (specialChars[ch]) { - break; - } - strBuf.push(String.fromCharCode(ch)); - continue; - } - strBuf.push(String.fromCharCode((x << 4) | x2)); - } else { - strBuf.push('#', String.fromCharCode(ch)); + if (divideBy !== 0) { // We are after a point. + divideBy *= 10; } + baseValue = baseValue * 10 + currentDigit; + } + } else if (ch === 0x2E) { // '.' + if (divideBy === 0) { + divideBy = 1; } else { - strBuf.push(String.fromCharCode(ch)); - } - } - if (strBuf.length > 127) { - warn('name token is longer than allowed by the spec: ' + strBuf.length); - } - return Name.get(strBuf.join('')); - }, - getHexString: function Lexer_getHexString() { - var strBuf = this.strBuf; - strBuf.length = 0; - var ch = this.currentChar; - var isFirstHex = true; - var firstDigit; - var secondDigit; - while (true) { - if (ch < 0) { - warn('Unterminated hex string'); - break; - } else if (ch === 0x3E) { // '>' - this.nextChar(); - break; - } else if (specialChars[ch] === 1) { - ch = this.nextChar(); - continue; - } else { - if (isFirstHex) { - firstDigit = toHexDigit(ch); - if (firstDigit === -1) { - warn('Ignoring invalid character "' + ch + '" in hex string'); - ch = this.nextChar(); - continue; - } - } else { - secondDigit = toHexDigit(ch); - if (secondDigit === -1) { - warn('Ignoring invalid character "' + ch + '" in hex string'); - ch = this.nextChar(); - continue; - } - strBuf.push(String.fromCharCode((firstDigit << 4) | secondDigit)); - } - isFirstHex = !isFirstHex; - ch = this.nextChar(); - } - } - return strBuf.join(''); - }, - getObj: function Lexer_getObj() { - // skip whitespace and comments - var comment = false; - var ch = this.currentChar; - while (true) { - if (ch < 0) { - return EOF; - } - if (comment) { - if (ch === 0x0A || ch === 0x0D) { // LF, CR - comment = false; - } - } else if (ch === 0x25) { // '%' - comment = true; - } else if (specialChars[ch] !== 1) { + // A number can have only one dot. break; } - ch = this.nextChar(); + } else if (ch === 0x2D) { // '-' + // Ignore minus signs in the middle of numbers to match + // Adobe's behavior. + warn('Badly formatted number: minus sign in the middle'); + } else if (ch === 0x45 || ch === 0x65) { // 'E', 'e' + // 'E' can be either a scientific notation or the beginning of a new + // operator. + ch = this.peekChar(); + if (ch === 0x2B || ch === 0x2D) { // '+', '-' + powerValueSign = (ch === 0x2D) ? -1 : 1; + this.nextChar(); // Consume the sign character. + } else if (ch < 0x30 || ch > 0x39) { // '0' - '9' + // The 'E' must be the beginning of a new operator. + break; + } + eNotation = true; + } else { + // The last character doesn't belong to us. + break; } + } - // start reading token + if (divideBy !== 0) { + baseValue /= divideBy; + } + if (eNotation) { + baseValue *= Math.pow(10, powerValueSign * powerValue); + } + return sign * baseValue; + } + + getString() { + let numParen = 1; + let done = false; + const strBuf = this.strBuf; + strBuf.length = 0; + + let ch = this.nextChar(); + while (true) { + let charBuffered = false; switch (ch | 0) { - case 0x30: case 0x31: case 0x32: case 0x33: case 0x34: // '0'-'4' - case 0x35: case 0x36: case 0x37: case 0x38: case 0x39: // '5'-'9' - case 0x2B: case 0x2D: case 0x2E: // '+', '-', '.' - return this.getNumber(); + case -1: + warn('Unterminated string'); + done = true; + break; case 0x28: // '(' - return this.getString(); - case 0x2F: // '/' - return this.getName(); - // array punctuation - case 0x5B: // '[' - this.nextChar(); - return Cmd.get('['); - case 0x5D: // ']' - this.nextChar(); - return Cmd.get(']'); - // hex string or dict punctuation - case 0x3C: // '<' - ch = this.nextChar(); - if (ch === 0x3C) { - // dict punctuation - this.nextChar(); - return Cmd.get('<<'); - } - return this.getHexString(); - // dict punctuation - case 0x3E: // '>' - ch = this.nextChar(); - if (ch === 0x3E) { - this.nextChar(); - return Cmd.get('>>'); - } - return Cmd.get('>'); - case 0x7B: // '{' - this.nextChar(); - return Cmd.get('{'); - case 0x7D: // '}' - this.nextChar(); - return Cmd.get('}'); + ++numParen; + strBuf.push('('); + break; case 0x29: // ')' - // Consume the current character in order to avoid permanently hanging - // the worker thread if `Lexer.getObject` is called from within a loop - // containing try-catch statements, since we would otherwise attempt - // to parse the *same* character over and over (fixes issue8061.pdf). - this.nextChar(); - throw new FormatError(`Illegal character: ${ch}`); - } - - // command - var str = String.fromCharCode(ch); - var knownCommands = this.knownCommands; - var knownCommandFound = knownCommands && knownCommands[str] !== undefined; - while ((ch = this.nextChar()) >= 0 && !specialChars[ch]) { - // stop if known command is found and next character does not make - // the str a command - var possibleCommand = str + String.fromCharCode(ch); - if (knownCommandFound && knownCommands[possibleCommand] === undefined) { - break; - } - if (str.length === 128) { - throw new FormatError(`Command token too long: ${str.length}`); - } - str = possibleCommand; - knownCommandFound = knownCommands && knownCommands[str] !== undefined; - } - if (str === 'true') { - return true; - } - if (str === 'false') { - return false; - } - if (str === 'null') { - return null; - } - - if (str === 'BI') { - // Keep track of the current stream position, since it's needed in order - // to correctly cache inline images; see `Parser.makeInlineImage`. - this.beginInlineImagePos = this.stream.pos; - } - - return Cmd.get(str); - }, - skipToNextLine: function Lexer_skipToNextLine() { - var ch = this.currentChar; - while (ch >= 0) { - if (ch === 0x0D) { // CR - ch = this.nextChar(); - if (ch === 0x0A) { // LF - this.nextChar(); + if (--numParen === 0) { + this.nextChar(); // consume strings ')' + done = true; + } else { + strBuf.push(')'); } break; - } else if (ch === 0x0A) { // LF - this.nextChar(); + case 0x5C: // '\\' + ch = this.nextChar(); + switch (ch) { + case -1: + warn('Unterminated string'); + done = true; + break; + case 0x6E: // 'n' + strBuf.push('\n'); + break; + case 0x72: // 'r' + strBuf.push('\r'); + break; + case 0x74: // 't' + strBuf.push('\t'); + break; + case 0x62: // 'b' + strBuf.push('\b'); + break; + case 0x66: // 'f' + strBuf.push('\f'); + break; + case 0x5C: // '\' + case 0x28: // '(' + case 0x29: // ')' + strBuf.push(String.fromCharCode(ch)); + break; + case 0x30: case 0x31: case 0x32: case 0x33: // '0'-'3' + case 0x34: case 0x35: case 0x36: case 0x37: // '4'-'7' + let x = ch & 0x0F; + ch = this.nextChar(); + charBuffered = true; + if (ch >= 0x30 && ch <= 0x37) { // '0'-'7' + x = (x << 3) + (ch & 0x0F); + ch = this.nextChar(); + if (ch >= 0x30 && ch <= 0x37) { // '0'-'7' + charBuffered = false; + x = (x << 3) + (ch & 0x0F); + } + } + strBuf.push(String.fromCharCode(x)); + break; + case 0x0D: // CR + if (this.peekChar() === 0x0A) { // LF + this.nextChar(); + } + break; + case 0x0A: // LF + break; + default: + strBuf.push(String.fromCharCode(ch)); + break; + } break; - } + default: + strBuf.push(String.fromCharCode(ch)); + break; + } + if (done) { + break; + } + if (!charBuffered) { ch = this.nextChar(); } - }, - }; + } + return strBuf.join(''); + } - return Lexer; -})(); + getName() { + let ch, previousCh; + const strBuf = this.strBuf; + strBuf.length = 0; + + while ((ch = this.nextChar()) >= 0 && !specialChars[ch]) { + if (ch === 0x23) { // '#' + ch = this.nextChar(); + if (specialChars[ch]) { + warn('Lexer_getName: ' + + 'NUMBER SIGN (#) should be followed by a hexadecimal number.'); + strBuf.push('#'); + break; + } + const x = toHexDigit(ch); + if (x !== -1) { + previousCh = ch; + ch = this.nextChar(); + const x2 = toHexDigit(ch); + if (x2 === -1) { + warn(`Lexer_getName: Illegal digit (${String.fromCharCode(ch)}) ` + + 'in hexadecimal number.'); + strBuf.push('#', String.fromCharCode(previousCh)); + if (specialChars[ch]) { + break; + } + strBuf.push(String.fromCharCode(ch)); + continue; + } + strBuf.push(String.fromCharCode((x << 4) | x2)); + } else { + strBuf.push('#', String.fromCharCode(ch)); + } + } else { + strBuf.push(String.fromCharCode(ch)); + } + } + if (strBuf.length > 127) { + warn(`Name token is longer than allowed by the spec: ${strBuf.length}`); + } + return Name.get(strBuf.join('')); + } + + getHexString() { + const strBuf = this.strBuf; + strBuf.length = 0; + let ch = this.currentChar; + let isFirstHex = true; + let firstDigit, secondDigit; + + while (true) { + if (ch < 0) { + warn('Unterminated hex string'); + break; + } else if (ch === 0x3E) { // '>' + this.nextChar(); + break; + } else if (specialChars[ch] === 1) { + ch = this.nextChar(); + continue; + } else { + if (isFirstHex) { + firstDigit = toHexDigit(ch); + if (firstDigit === -1) { + warn(`Ignoring invalid character "${ch}" in hex string`); + ch = this.nextChar(); + continue; + } + } else { + secondDigit = toHexDigit(ch); + if (secondDigit === -1) { + warn(`Ignoring invalid character "${ch}" in hex string`); + ch = this.nextChar(); + continue; + } + strBuf.push(String.fromCharCode((firstDigit << 4) | secondDigit)); + } + isFirstHex = !isFirstHex; + ch = this.nextChar(); + } + } + return strBuf.join(''); + } + + getObj() { + // Skip whitespace and comments. + let comment = false; + let ch = this.currentChar; + while (true) { + if (ch < 0) { + return EOF; + } + if (comment) { + if (ch === 0x0A || ch === 0x0D) { // LF, CR + comment = false; + } + } else if (ch === 0x25) { // '%' + comment = true; + } else if (specialChars[ch] !== 1) { + break; + } + ch = this.nextChar(); + } + + // Start reading a token. + switch (ch | 0) { + case 0x30: case 0x31: case 0x32: case 0x33: case 0x34: // '0'-'4' + case 0x35: case 0x36: case 0x37: case 0x38: case 0x39: // '5'-'9' + case 0x2B: case 0x2D: case 0x2E: // '+', '-', '.' + return this.getNumber(); + case 0x28: // '(' + return this.getString(); + case 0x2F: // '/' + return this.getName(); + // array punctuation + case 0x5B: // '[' + this.nextChar(); + return Cmd.get('['); + case 0x5D: // ']' + this.nextChar(); + return Cmd.get(']'); + // hex string or dict punctuation + case 0x3C: // '<' + ch = this.nextChar(); + if (ch === 0x3C) { + // dict punctuation + this.nextChar(); + return Cmd.get('<<'); + } + return this.getHexString(); + // dict punctuation + case 0x3E: // '>' + ch = this.nextChar(); + if (ch === 0x3E) { + this.nextChar(); + return Cmd.get('>>'); + } + return Cmd.get('>'); + case 0x7B: // '{' + this.nextChar(); + return Cmd.get('{'); + case 0x7D: // '}' + this.nextChar(); + return Cmd.get('}'); + case 0x29: // ')' + // Consume the current character in order to avoid permanently hanging + // the worker thread if `Lexer.getObject` is called from within a loop + // containing try-catch statements, since we would otherwise attempt + // to parse the *same* character over and over (fixes issue8061.pdf). + this.nextChar(); + throw new FormatError(`Illegal character: ${ch}`); + } + + // Start reading a command. + let str = String.fromCharCode(ch); + const knownCommands = this.knownCommands; + let knownCommandFound = knownCommands && knownCommands[str] !== undefined; + while ((ch = this.nextChar()) >= 0 && !specialChars[ch]) { + // Stop if a known command is found and next character does not make + // the string a command. + const possibleCommand = str + String.fromCharCode(ch); + if (knownCommandFound && knownCommands[possibleCommand] === undefined) { + break; + } + if (str.length === 128) { + throw new FormatError(`Command token too long: ${str.length}`); + } + str = possibleCommand; + knownCommandFound = knownCommands && knownCommands[str] !== undefined; + } + if (str === 'true') { + return true; + } + if (str === 'false') { + return false; + } + if (str === 'null') { + return null; + } + + if (str === 'BI') { + // Keep track of the current stream position, since it's needed in order + // to correctly cache inline images; see `Parser.makeInlineImage`. + this.beginInlineImagePos = this.stream.pos; + } + + return Cmd.get(str); + } + + skipToNextLine() { + let ch = this.currentChar; + while (ch >= 0) { + if (ch === 0x0D) { // CR + ch = this.nextChar(); + if (ch === 0x0A) { // LF + this.nextChar(); + } + break; + } else if (ch === 0x0A) { // LF + this.nextChar(); + break; + } + ch = this.nextChar(); + } + } +} var Linearization = { create: function LinearizationCreate(stream) {