Merge pull request #3424 from yurydelendik/lookChar

lookChar refactoring

src/chunked_stream.js

@@ -118,7 +118,7 @@ var ChunkedStream = (function ChunkedStreamClosure() {
     getByte: function ChunkedStream_getByte() {
       var pos = this.pos;
       if (pos >= this.end) {
-        return null;
+        return -1;
       }
       this.ensureRange(pos, pos + 1);
       return this.bytes[this.pos++];
@@ -156,22 +156,6 @@ var ChunkedStream = (function ChunkedStreamClosure() {
       return this.bytes.subarray(begin, end);
     },
 
-    lookChar: function ChunkedStream_lookChar() {
-      var pos = this.pos;
-      if (pos >= this.end)
-        return null;
-      this.ensureRange(pos, pos + 1);
-      return String.fromCharCode(this.bytes[pos]);
-    },
-
-    getChar: function ChunkedStream_getChar() {
-      var pos = this.pos;
-      if (pos >= this.end)
-        return null;
-      this.ensureRange(pos, pos + 1);
-      return String.fromCharCode(this.bytes[this.pos++]);
-    },
-
     skip: function ChunkedStream_skip(n) {
       if (!n)
         n = 1;

src/core.js

@@ -313,7 +313,7 @@ var PDFDocument = (function PDFDocumentClosure() {
     if (pos + limit > end)
       limit = end - pos;
     for (var n = 0; n < limit; ++n)
-      str += stream.getChar();
+      str += String.fromCharCode(stream.getByte());
     stream.pos = pos;
     var index = backwards ? str.lastIndexOf(needle) : str.indexOf(needle);
     if (index == -1)
@@ -392,12 +392,12 @@ var PDFDocument = (function PDFDocumentClosure() {
           stream.skip(9);
           var ch;
           do {
-            ch = stream.getChar();
+            ch = stream.getByte();
           } while (Lexer.isSpace(ch));
           var str = '';
-          while ((ch - '0') <= 9) {
+          while (ch >= 0x20 && ch <= 0x39) { // < '9'
-            str += ch;
+            str += String.fromCharCode(ch);
-            ch = stream.getChar();
+            ch = stream.getByte();
           }
           startXRef = parseInt(str, 10);
           if (isNaN(startXRef))
@@ -426,11 +426,11 @@ var PDFDocument = (function PDFDocumentClosure() {
         // Reading file format version
         var MAX_VERSION_LENGTH = 12;
         var version = '', ch;
-        while ((ch = stream.getChar()) > ' ') {
+        while ((ch = stream.getByte()) > 0x20) { // SPACE
           if (version.length >= MAX_VERSION_LENGTH) {
             break;
           }
-          version += ch;
+          version += String.fromCharCode(ch);
         }
         // removing "%PDF-"-prefix
         this.pdfFormatVersion = version.substring(5);

src/fonts.js

@@ -3562,8 +3562,9 @@ var Font = (function FontClosure() {
             while (font.pos < end) {
               var stringLength = font.getByte();
               var string = '';
-              for (var i = 0; i < stringLength; ++i)
+              for (var i = 0; i < stringLength; ++i) {
-                string += font.getChar();
+                string += String.fromCharCode(font.getByte());
+              }
               customNames.push(string);
             }
             glyphNames = [];
@@ -5170,10 +5171,10 @@ var Type1Parser = (function Type1ParserClosure() {
   }
 
   function isSpecial(c) {
-    return c === '/' ||
+    return c === 0x2F || // '/'
-           c === '[' || c === ']' ||
+           c === 0x5B || c === 0x5D || // '[', ']'
-           c === '{' || c === '}' ||
+           c === 0x7B || c === 0x7D || // '{', '}'
-           c === '(' || c === ')';
+           c === 0x28 || c === 0x29; // '(', ')'
   }
 
   function Type1Parser(stream, encrypted) {
@@ -5181,6 +5182,7 @@ var Type1Parser = (function Type1ParserClosure() {
       stream = new Stream(decrypt(stream.getBytes(), EEXEC_ENCRYPT_KEY, 4));
     }
     this.stream = stream;
+    this.nextChar();
   }
 
   Type1Parser.prototype = {
@@ -5216,36 +5218,39 @@ var Type1Parser = (function Type1ParserClosure() {
       return token === 'true' ? 1 : 0;
     },
 
+    nextChar : function Type1_nextChar() {
+      return (this.currentChar = this.stream.getByte());
+    },
+
     getToken: function Type1Parser_getToken() {
       // Eat whitespace and comments.
       var comment = false;
-      var ch;
+      var ch = this.currentChar;
-      var stream = this.stream;
       while (true) {
-        if ((ch = stream.lookChar()) === null)
+        if (ch === -1) {
           return null;
+        }
 
         if (comment) {
-          if (ch === '\x0a' || ch === '\x0d') {
+          if (ch === 0x0A || ch === 0x0D) {
             comment = false;
           }
-        } else if (ch === '%') {
+        } else if (ch === 0x25) { // '%'
           comment = true;
         } else if (!Lexer.isSpace(ch)) {
           break;
         }
-        stream.skip();
+        ch = this.nextChar();
       }
       if (isSpecial(ch)) {
-        stream.skip();
+        this.nextChar();
-        return ch;
+        return String.fromCharCode(ch);
       }
       var token = '';
       do {
-        token += ch;
+        token += String.fromCharCode(ch);
-        stream.skip();
+        ch = this.nextChar();
-        ch = stream.lookChar();
+      } while (ch >= 0 && !Lexer.isSpace(ch) && !isSpecial(ch));
-      } while (ch !== null && !Lexer.isSpace(ch) && !isSpecial(ch));
       return token;
     },
 
@@ -5292,12 +5297,13 @@ var Type1Parser = (function Type1ParserClosure() {
               var glyph = this.getToken();
               var length = this.readInt();
               this.getToken(); // read in 'RD' or '-|'
-              var data = stream.makeSubStream(stream.pos + 1, length);
+              var data = stream.makeSubStream(stream.pos, length);
               var lenIV = program.properties.privateData['lenIV'];
               var encoded = decrypt(data.getBytes(), CHAR_STRS_ENCRYPT_KEY,
                                     lenIV);
               // Skip past the required space and binary data.
-              stream.skip(1 + length);
+              stream.skip(length);
+              this.nextChar();
               token = this.getToken(); // read in 'ND' or '|-'
               if (token === 'noaccess') {
                 this.getToken(); // read in 'def'
@@ -5315,12 +5321,13 @@ var Type1Parser = (function Type1ParserClosure() {
               var index = this.readInt();
               var length = this.readInt();
               this.getToken(); // read in 'RD' or '-|'
-              var data = stream.makeSubStream(stream.pos + 1, length);
+              var data = stream.makeSubStream(stream.pos, length);
               var lenIV = program.properties.privateData['lenIV'];
               var encoded = decrypt(data.getBytes(), CHAR_STRS_ENCRYPT_KEY,
                                     lenIV);
               // Skip past the required space and binary data.
-              stream.skip(1 + length);
+              stream.skip(length);
+              this.nextChar();
               token = this.getToken(); // read in 'NP' or '|'
               if (token === 'noaccess') {
                 this.getToken(); // read in 'put'

src/function.js

@@ -816,53 +816,54 @@ var PostScriptToken = (function PostScriptTokenClosure() {
 var PostScriptLexer = (function PostScriptLexerClosure() {
   function PostScriptLexer(stream) {
     this.stream = stream;
+    this.nextChar();
   }
   PostScriptLexer.prototype = {
+    nextChar: function PostScriptLexer_nextChar() {
+      return (this.currentChar = this.stream.getByte());
+    },
     getToken: function PostScriptLexer_getToken() {
       var s = '';
-      var ch;
       var comment = false;
-      var stream = this.stream;
+      var ch = this.currentChar;
 
       // skip comments
       while (true) {
-        if (!(ch = stream.getChar()))
+        if (ch < 0) {
           return EOF;
+        }
 
         if (comment) {
-          if (ch == '\x0a' || ch == '\x0d')
+          if (ch === 0x0A || ch === 0x0D) {
             comment = false;
-        } else if (ch == '%') {
+          }
+        } else if (ch == 0x25) { // '%'
           comment = true;
         } else if (!Lexer.isSpace(ch)) {
           break;
         }
+        ch = this.nextChar();
       }
-      switch (ch) {
+      switch (ch | 0) {
-        case '0': case '1': case '2': case '3': case '4':
+        case 0x30: case 0x31: case 0x32: case 0x33: case 0x34: // '0'-'4'
-        case '5': case '6': case '7': case '8': case '9':
+        case 0x35: case 0x36: case 0x37: case 0x38: case 0x39: // '5'-'9'
-        case '+': case '-': case '.':
+        case 0x2B: case 0x2D: case 0x2E: // '+', '-', '.'
           return new PostScriptToken(PostScriptTokenTypes.NUMBER,
-                                      this.getNumber(ch));
+                                      this.getNumber());
-        case '{':
+        case 0x7B: // '{'
+          this.nextChar();
           return PostScriptToken.LBRACE;
-        case '}':
+        case 0x7D: // '}'
+          this.nextChar();
           return PostScriptToken.RBRACE;
       }
       // operator
-      var str = ch.toLowerCase();
+      var str = String.fromCharCode(ch);
-      while (true) {
+      while ((ch = this.nextChar()) >= 0 && // and 'A'-'Z', 'a'-'z'
-        ch = stream.lookChar();
+             ((ch >= 0x41 && ch <= 0x5A) || (ch >= 0x61 && ch <= 0x7A))) {
-        if (ch === null)
+        str += String.fromCharCode(ch);
-          break;
-        ch = ch.toLowerCase();
-        if (ch >= 'a' && ch <= 'z')
-          str += ch;
-        else
-          break;
-        stream.skip();
       }
-      switch (str) {
+      switch (str.toLowerCase()) {
         case 'if':
           return PostScriptToken.IF;
         case 'ifelse':
@@ -871,16 +872,16 @@ var PostScriptLexer = (function PostScriptLexerClosure() {
           return PostScriptToken.getOperator(str);
       }
     },
-    getNumber: function PostScriptLexer_getNumber(ch) {
+    getNumber: function PostScriptLexer_getNumber() {
-      var str = ch;
+      var ch = this.currentChar;
-      var stream = this.stream;
+      var str = String.fromCharCode(ch);
-      while (true) {
+      while ((ch = this.nextChar()) >= 0) {
-        ch = stream.lookChar();
+        if ((ch >= 0x30 && ch <= 0x39) || // '0'-'9'
-        if ((ch >= '0' && ch <= '9') || ch == '-' || ch == '.')
+             ch === 0x2D || ch === 0x2E) { // '-', '.'
-          str += ch;
+          str += String.fromCharCode(ch);
-        else
+        } else {
           break;
-        stream.skip();
+        }
       }
       var value = parseFloat(str);
       if (isNaN(value))

src/parser.js

@@ -59,8 +59,6 @@ var Parser = (function ParserClosure() {
       if (isCmd(this.buf2, 'ID')) {
         this.buf1 = this.buf2;
         this.buf2 = null;
-        // skip byte after ID
-        this.lexer.skip();
       } else {
         this.buf1 = this.buf2;
         this.buf2 = this.lexer.getObj();
@@ -155,9 +153,8 @@ var Parser = (function ParserClosure() {
 
       // searching for the /EI\s/
       var state = 0, ch, i, ii;
-      while (state != 4 &&
+      while (state != 4 && (ch = stream.getByte()) !== -1) {
-             (ch = stream.getByte()) !== null && ch !== undefined) {
+        switch (ch | 0) {
-        switch (ch) {
           case 0x20:
           case 0x0D:
           case 0x0A:
@@ -165,7 +162,8 @@ var Parser = (function ParserClosure() {
             var followingBytes = stream.peekBytes(5);
             for (i = 0, ii = followingBytes.length; i < ii; i++) {
               ch = followingBytes[i];
-              if (ch !== 0x0A && ch != 0x0D && (ch < 0x20 || ch > 0x7F)) {
+              if (ch !== 0x0A && ch !== 0x0D && (ch < 0x20 || ch > 0x7F)) {
+                // not a LF, CR, SPACE or any visible ASCII character
                 state = 0;
                 break; // some binary stuff found, resetting the state
               }
@@ -206,7 +204,7 @@ var Parser = (function ParserClosure() {
 
       // get stream start position
       lexer.skipToNextLine();
-      var pos = stream.pos;
+      var pos = stream.pos - 1;
 
       // get length
       var length = this.fetchIfRef(dict.get('Length'));
@@ -215,6 +213,8 @@ var Parser = (function ParserClosure() {
 
       // skip over the stream data
       stream.pos = pos + length;
+      lexer.nextChar();
+
       this.shift(); // '>>'
       this.shift(); // 'stream'
       if (!isCmd(this.buf1, 'endstream')) {
@@ -254,6 +254,8 @@ var Parser = (function ParserClosure() {
           error('Missing endstream');
         }
         length = skipped;
+
+        lexer.nextChar();
         this.shift();
         this.shift();
       }
@@ -344,6 +346,8 @@ var Parser = (function ParserClosure() {
 var Lexer = (function LexerClosure() {
   function Lexer(stream, knownCommands) {
     this.stream = stream;
+    this.nextChar();
+
     // The PDFs might have "glued" commands with other commands, operands or
     // literals, e.g. "q1". The knownCommands is a dictionary of the valid
     // commands and their prefixes. The prefixes are built the following way:
@@ -355,7 +359,8 @@ var Lexer = (function LexerClosure() {
   }
 
   Lexer.isSpace = function Lexer_isSpace(ch) {
-    return ch == ' ' || ch == '\t' || ch == '\x0d' || ch == '\x0a';
+    // space is one of the following characters: SPACE, TAB, CR, or LF
+    return ch === 0x20 || ch === 0x09 || ch === 0x0D || ch === 0x0A;
   };
 
   // A '1' in this array means the character is white space.  A '1' or
@@ -380,36 +385,40 @@ var Lexer = (function LexerClosure() {
   ];
 
   function toHexDigit(ch) {
-    if (ch >= '0' && ch <= '9')
+    if (ch >= 0x30 && ch <= 0x39) { // '0'-'9'
-      return ch.charCodeAt(0) - 48;
+      return ch & 0x0F;
-    ch = ch.toUpperCase();
+    }
-    if (ch >= 'A' && ch <= 'F')
+    if ((ch >= 0x41 && ch <= 0x46) || (ch >= 0x61 && ch <= 0x66)) {
-      return ch.charCodeAt(0) - 55;
+      // 'A'-'F', 'a'-'f'
+      return (ch & 0x0F) + 9;
+    }
     return -1;
   }
 
   Lexer.prototype = {
-    getNumber: function Lexer_getNumber(ch) {
+    nextChar: function Lexer_nextChar() {
+      return (this.currentChar = this.stream.getByte());
+    },
+    getNumber: function Lexer_getNumber() {
       var floating = false;
-      var str = ch;
+      var ch = this.currentChar;
-      var stream = this.stream;
+      var str = String.fromCharCode(ch);
-      while ((ch = stream.lookChar())) {
+      while ((ch = this.nextChar()) >= 0) {
-        if (ch == '.' && !floating) {
+        if (ch === 0x2E && !floating) { // '.'
-          str += ch;
+          str += '.';
           floating = true;
-        } else if (ch == '-') {
+        } else if (ch === 0x2D) { // '-'
           // ignore minus signs in the middle of numbers to match
           // Adobe's behavior
           warn('Badly formated number');
-        } else if (ch >= '0' && ch <= '9') {
+        } else if (ch >= 0x30 && ch <= 0x39) { // '0'-'9'
-          str += ch;
+          str += String.fromCharCode(ch);
-        } else if (ch == 'e' || ch == 'E') {
+        } else if (ch === 0x45 || ch === 0x65) { // 'E', 'e'
           floating = true;
         } else {
           // the last character doesn't belong to us
           break;
         }
-        stream.skip();
       }
       var value = parseFloat(str);
       if (isNaN(value))
@@ -420,148 +429,150 @@ var Lexer = (function LexerClosure() {
       var numParen = 1;
       var done = false;
       var str = '';
-      var stream = this.stream;
+
-      var ch;
+      var ch = this.nextChar();
-      do {
+      while (true) {
-        ch = stream.getChar();
+        var charBuffered = false;
-        switch (ch) {
+        switch (ch | 0) {
-          case null:
+          case -1:
-          case undefined:
             warn('Unterminated string');
             done = true;
             break;
-          case '(':
+          case 0x28: // '('
             ++numParen;
-            str += ch;
+            str += '(';
             break;
-          case ')':
+          case 0x29: // ')'
             if (--numParen === 0) {
+              this.nextChar(); // consume strings ')'
               done = true;
             } else {
-              str += ch;
+              str += ')';
             }
             break;
-          case '\\':
+          case 0x5C: // '\\'
-            ch = stream.getChar();
+            ch = this.nextChar();
             switch (ch) {
-              case null:
+              case -1:
-              case undefined:
                 warn('Unterminated string');
                 done = true;
                 break;
-              case 'n':
+              case 0x6E: // 'n'
                 str += '\n';
                 break;
-              case 'r':
+              case 0x72: // 'r'
                 str += '\r';
                 break;
-              case 't':
+              case 0x74: // 't'
                 str += '\t';
                 break;
-              case 'b':
+              case 0x62: // 'b'
                 str += '\b';
                 break;
-              case 'f':
+              case 0x66: // 'f'
                 str += '\f';
                 break;
-              case '\\':
+              case 0x5C: // '\'
-              case '(':
+              case 0x28: // '('
-              case ')':
+              case 0x29: // ')'
-                str += ch;
+                str += String.fromCharCode(ch);
                 break;
-              case '0': case '1': case '2': case '3':
+              case 0x30: case 0x31: case 0x32: case 0x33: // '0'-'3'
-              case '4': case '5': case '6': case '7':
+              case 0x34: case 0x35: case 0x36: case 0x37: // '4'-'7'
-                var x = ch - '0';
+                var x = ch & 0x0F;
-                ch = stream.lookChar();
+                ch = this.nextChar();
-                if (ch >= '0' && ch <= '7') {
+                charBuffered = true;
-                  stream.skip();
+                if (ch >= 0x30 && ch <= 0x37) { // '0'-'7'
-                  x = (x << 3) + (ch - '0');
+                  x = (x << 3) + (ch & 0x0F);
-                  ch = stream.lookChar();
+                  ch = this.nextChar();
-                  if (ch >= '0' && ch <= '7') {
+                  if (ch >= 0x30 && ch <= 0x37) {  // '0'-'7'
-                    stream.skip();
+                    charBuffered = false;
-                    x = (x << 3) + (ch - '0');
+                    x = (x << 3) + (ch & 0x0F);
                   }
                 }
 
                 str += String.fromCharCode(x);
                 break;
-              case '\r':
+              case 0x0A: case 0x0D: // LF, CR
-                ch = stream.lookChar();
-                if (ch == '\n')
-                  stream.skip();
-                break;
-              case '\n':
                 break;
               default:
-                str += ch;
+                str += String.fromCharCode(ch);
                 break;
             }
             break;
           default:
-            str += ch;
+            str += String.fromCharCode(ch);
+            break;
+        }
+        if (done) {
           break;
         }
-      } while (!done);
+        if (!charBuffered) {
+          ch = this.nextChar();
+        }
+      }
       return str;
     },
-    getName: function Lexer_getName(ch) {
+    getName: function Lexer_getName() {
-      var str = '';
+      var str = '', ch;
-      var stream = this.stream;
+      while ((ch = this.nextChar()) >= 0 && !specialChars[ch]) {
-      while (!!(ch = stream.lookChar()) && !specialChars[ch.charCodeAt(0)]) {
+        if (ch === 0x23) { // '#'
-        stream.skip();
+          ch = this.nextChar();
-        if (ch == '#') {
-          ch = stream.lookChar();
           var x = toHexDigit(ch);
           if (x != -1) {
-            stream.skip();
+            var x2 = toHexDigit(this.nextChar());
-            var x2 = toHexDigit(stream.getChar());
             if (x2 == -1)
               error('Illegal digit in hex char in name: ' + x2);
             str += String.fromCharCode((x << 4) | x2);
           } else {
             str += '#';
-            str += ch;
+            str += String.fromCharCode(ch);
           }
         } else {
-          str += ch;
+          str += String.fromCharCode(ch);
         }
       }
-      if (str.length > 128)
+      if (str.length > 128) {
         error('Warning: name token is longer than allowed by the spec: ' +
               str.length);
+      }
       return new Name(str);
     },
-    getHexString: function Lexer_getHexString(ch) {
+    getHexString: function Lexer_getHexString() {
       var str = '';
-      var stream = this.stream;
+      var ch = this.currentChar;
       var isFirstHex = true;
       var firstDigit;
       var secondDigit;
       while (true) {
-        ch = stream.getChar();
+        if (ch < 0) {
-        if (!ch) {
           warn('Unterminated hex string');
           break;
-        } else if (ch === '>') {
+        } else if (ch === 0x3E) { // '>'
+          this.nextChar();
           break;
-        } else if (specialChars[ch.charCodeAt(0)] === 1) {
+        } 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;
             }
             str += String.fromCharCode((firstDigit << 4) | secondDigit);
           }
           isFirstHex = !isFirstHex;
+          ch = this.nextChar();
         }
       }
       return str;
@@ -569,73 +580,81 @@ var Lexer = (function LexerClosure() {
     getObj: function Lexer_getObj() {
       // skip whitespace and comments
       var comment = false;
-      var stream = this.stream;
+      var ch = this.currentChar;
-      var ch;
       while (true) {
-        if (!(ch = stream.getChar()))
+        if (ch < 0) {
           return EOF;
+        }
         if (comment) {
-          if (ch == '\r' || ch == '\n')
+          if (ch === 0x0A || ch == 0x0D) // LF, CR
             comment = false;
-        } else if (ch == '%') {
+        } else if (ch === 0x25) { // '%'
           comment = true;
-        } else if (specialChars[ch.charCodeAt(0)] != 1) {
+        } else if (specialChars[ch] !== 1) {
           break;
         }
+        ch = this.nextChar();
       }
 
       // start reading token
-      switch (ch) {
+      switch (ch | 0) {
-        case '0': case '1': case '2': case '3': case '4':
+        case 0x30: case 0x31: case 0x32: case 0x33: case 0x34: // '0'-'4'
-        case '5': case '6': case '7': case '8': case '9':
+        case 0x35: case 0x36: case 0x37: case 0x38: case 0x39: // '5'-'9'
-        case '+': case '-': case '.':
+        case 0x2B: case 0x2D: case 0x2E: // '+', '-', '.'
-          return this.getNumber(ch);
+          return this.getNumber();
-        case '(':
+        case 0x28: // '('
           return this.getString();
-        case '/':
+        case 0x2F: // '/'
-          return this.getName(ch);
+          return this.getName();
         // array punctuation
-        case '[':
+        case 0x5B: // '['
-        case ']':
+          this.nextChar();
-          return Cmd.get(ch);
+          return Cmd.get('[');
+        case 0x5D: // ']'
+          this.nextChar();
+          return Cmd.get(']');
         // hex string or dict punctuation
-        case '<':
+        case 0x3C: // '<'
-          ch = stream.lookChar();
+          ch = this.nextChar();
-          if (ch == '<') {
+          if (ch === 0x3C) {
             // dict punctuation
-            stream.skip();
+            this.nextChar();
             return Cmd.get('<<');
           }
-          return this.getHexString(ch);
+          return this.getHexString();
         // dict punctuation
-        case '>':
+        case 0x3E: // '>'
-          ch = stream.lookChar();
+          ch = this.nextChar();
-          if (ch == '>') {
+          if (ch === 0x3E) {
-            stream.skip();
+            this.nextChar();
             return Cmd.get('>>');
           }
-          return Cmd.get(ch);
+          return Cmd.get('>');
-        case '{':
+        case 0x7B: // '{'
-        case '}':
+          this.nextChar();
-          return Cmd.get(ch);
+          return Cmd.get('{');
-        // fall through
+        case 0x7D: // '}'
-        case ')':
+          this.nextChar();
+          return Cmd.get('}');
+        case 0x29: // ')'
           error('Illegal character: ' + ch);
+          break;
       }
 
       // command
-      var str = ch;
+      var str = String.fromCharCode(ch);
       var knownCommands = this.knownCommands;
       var knownCommandFound = knownCommands && (str in knownCommands);
-      while (!!(ch = stream.lookChar()) && !specialChars[ch.charCodeAt(0)]) {
+      while ((ch = this.nextChar()) >= 0 && !specialChars[ch]) {
         // stop if known command is found and next character does not make
         // the str a command
-        if (knownCommandFound && !((str + ch) in knownCommands))
+        var possibleCommand = str + String.fromCharCode(ch);
+        if (knownCommandFound && !(possibleCommand in knownCommands)) {
           break;
-        stream.skip();
+        }
         if (str.length == 128)
           error('Command token too long: ' + str.length);
-        str += ch;
+        str = possibleCommand;
         knownCommandFound = knownCommands && (str in knownCommands);
       }
       if (str == 'true')
@@ -648,19 +667,20 @@ var Lexer = (function LexerClosure() {
     },
     skipToNextLine: function Lexer_skipToNextLine() {
       var stream = this.stream;
-      while (true) {
+      var ch = this.currentChar;
-        var ch = stream.getChar();
+      while (ch >= 0) {
-        if (!ch || ch == '\n')
+        if (ch === 0x0D) { // CR
-          return;
+          ch = this.nextChar();
-        if (ch == '\r') {
+          if (ch === 0x0A) { // LF
-          if ((ch = stream.lookChar()) == '\n')
+            this.nextChar();
-            stream.skip();
-          return;
           }
+          break;
+        } else if (ch === 0x0A) { // LF
+          this.nextChar();
+          break;
+        }
+        ch = this.nextChar();
       }
-    },
-    skip: function Lexer_skip() {
-      this.stream.skip();
     }
   };
 

src/stream.js

@@ -37,7 +37,7 @@ var Stream = (function StreamClosure() {
     },
     getByte: function Stream_getByte() {
       if (this.pos >= this.end)
-        return null;
+        return -1;
       return this.bytes[this.pos++];
     },
     // returns subarray of original buffer
@@ -62,16 +62,6 @@ var Stream = (function StreamClosure() {
       this.pos -= bytes.length;
       return bytes;
     },
-    lookChar: function Stream_lookChar() {
-      if (this.pos >= this.end)
-        return null;
-      return String.fromCharCode(this.bytes[this.pos]);
-    },
-    getChar: function Stream_getChar() {
-      if (this.pos >= this.end)
-        return null;
-      return String.fromCharCode(this.bytes[this.pos++]);
-    },
     skip: function Stream_skip(n) {
       if (!n)
         n = 1;
@@ -133,7 +123,7 @@ var DecodeStream = (function DecodeStreamClosure() {
       var pos = this.pos;
       while (this.bufferLength <= pos) {
         if (this.eof)
-          return null;
+          return -1;
         this.readBlock();
       }
       return this.buffer[this.pos++];
@@ -171,31 +161,13 @@ var DecodeStream = (function DecodeStreamClosure() {
       this.pos -= bytes.length;
       return bytes;
     },
-    lookChar: function DecodeStream_lookChar() {
-      var pos = this.pos;
-      while (this.bufferLength <= pos) {
-        if (this.eof)
-          return null;
-        this.readBlock();
-      }
-      return String.fromCharCode(this.buffer[this.pos]);
-    },
-    getChar: function DecodeStream_getChar() {
-      var pos = this.pos;
-      while (this.bufferLength <= pos) {
-        if (this.eof)
-          return null;
-        this.readBlock();
-      }
-      return String.fromCharCode(this.buffer[this.pos++]);
-    },
     makeSubStream: function DecodeStream_makeSubStream(start, length, dict) {
       var end = start + length;
       while (this.bufferLength <= end && !this.eof)
         this.readBlock();
       return new Stream(this.buffer, start, length, dict);
     },
-    skip: function DecodeStream_skip(n) {
+    skip: function Stream_skip(n) {
       if (!n)
         n = 1;
       this.pos += n;
@@ -901,9 +873,6 @@ var JpegStream = (function JpegStreamClosure() {
   JpegStream.prototype.getIR = function JpegStream_getIR() {
     return bytesToString(this.bytes);
   };
-  JpegStream.prototype.getChar = function JpegStream_getChar() {
-    error('internal error: getChar is not valid on JpegStream');
-  };
   /**
    * Checks if the image can be decoded and displayed by the browser without any
    * further processing such as color space conversions.
@@ -1031,9 +1000,6 @@ var JpxStream = (function JpxStreamClosure() {
     this.bufferLength = data.length;
     this.eof = true;
   };
-  JpxStream.prototype.getChar = function JpxStream_getChar() {
-    error('internal error: getChar is not valid on JpxStream');
-  };
 
   return JpxStream;
 })();
@@ -1076,9 +1042,6 @@ var Jbig2Stream = (function Jbig2StreamClosure() {
     this.bufferLength = dataLength;
     this.eof = true;
   };
-  Jbig2Stream.prototype.getChar = function Jbig2Stream_getChar() {
-    error('internal error: getChar is not valid on Jbig2Stream');
-  };
 
   return Jbig2Stream;
 })();
@@ -1139,15 +1102,18 @@ var Ascii85Stream = (function Ascii85StreamClosure() {
   Ascii85Stream.prototype = Object.create(DecodeStream.prototype);
 
   Ascii85Stream.prototype.readBlock = function Ascii85Stream_readBlock() {
-    var tildaCode = '~'.charCodeAt(0);
+    var TILDA_CHAR = 0x7E; // '~'
-    var zCode = 'z'.charCodeAt(0);
+    var Z_LOWER_CHAR = 0x7A; // 'z'
+    var EOF = -1;
+
     var str = this.str;
 
     var c = str.getByte();
-    while (Lexer.isSpace(String.fromCharCode(c)))
+    while (Lexer.isSpace(c)) {
       c = str.getByte();
+    }
 
-    if (!c || c === tildaCode) {
+    if (c === EOF || c === TILDA_CHAR) {
       this.eof = true;
       return;
     }
@@ -1155,7 +1121,7 @@ var Ascii85Stream = (function Ascii85StreamClosure() {
     var bufferLength = this.bufferLength, buffer;
 
     // special code for z
-    if (c == zCode) {
+    if (c == Z_LOWER_CHAR) {
       buffer = this.ensureBuffer(bufferLength + 4);
       for (var i = 0; i < 4; ++i)
         buffer[bufferLength + i] = 0;
@@ -1165,12 +1131,13 @@ var Ascii85Stream = (function Ascii85StreamClosure() {
       input[0] = c;
       for (var i = 1; i < 5; ++i) {
         c = str.getByte();
-        while (Lexer.isSpace(String.fromCharCode(c)))
+        while (Lexer.isSpace(c)) {
           c = str.getByte();
+        }
 
         input[i] = c;
 
-        if (!c || c == tildaCode)
+        if (c === EOF || c == TILDA_CHAR)
           break;
       }
       buffer = this.ensureBuffer(bufferLength + i - 1);
@@ -2258,7 +2225,7 @@ var CCITTFaxStream = (function CCITTFaxStreamClosure() {
   CCITTFaxStream.prototype.lookBits = function CCITTFaxStream_lookBits(n) {
     var c;
     while (this.inputBits < n) {
-      if ((c = this.str.getByte()) === null || c === undefined) {
+      if ((c = this.str.getByte()) === -1) {
         if (this.inputBits === 0)
           return EOF;
         return ((this.inputBuf << (n - this.inputBits)) &
@@ -2312,7 +2279,7 @@ var LZWStream = (function LZWStreamClosure() {
     var cachedData = this.cachedData;
     while (bitsCached < n) {
       var c = this.str.getByte();
-      if (c === null || c === undefined) {
+      if (c === -1) {
         this.eof = true;
         return null;
       }

src/util.js

@@ -623,7 +623,7 @@ function isArray(v) {
 
 function isStream(v) {
   return typeof v == 'object' && v !== null && v !== undefined &&
-         ('getChar' in v);
+         ('getBytes' in v);
 }
 
 function isArrayBuffer(v) {

test/unit/parser_spec.js

@@ -7,20 +7,20 @@
 describe('parser', function() {
   describe('Lexer', function() {
     it('should stop parsing numbers at the end of stream', function() {
-      var input = new StringStream('1.234');
+      var input = new StringStream('11.234');
       var lexer = new Lexer(input);
-      var result = lexer.getNumber('1');
+      var result = lexer.getNumber();
 
       expect(result).toEqual(11.234);
     });
 
     it('should stop parsing strings at the end of stream', function() {
-      var input = new StringStream('1$4)');
+      var input = new StringStream('(1$4)');
-      input.getChar = function(super_getChar) {
+      input.getByte = function(super_getByte) {
         // simulating end of file using null (see issue 2766)
-        var ch = super_getChar.call(input);
+        var ch = super_getByte.call(input);
-        return ch == '$' ? null : ch;
+        return ch === 0x24 /* '$' */ ? -1 : ch;
-      }.bind(input, input.getChar);
+      }.bind(input, input.getByte);
       var lexer = new Lexer(input);
       var result = lexer.getString();
 
@@ -31,9 +31,9 @@ describe('parser', function() {
       // '8 0 2 15 5 2 2 2 4 3 2 4'
       // should be parsed as
       // '80 21 55 22 24 32'
-      var input = new StringStream('7 0 2 15 5 2 2 2 4 3 2 4>');
+      var input = new StringStream('<7 0 2 15 5 2 2 2 4 3 2 4>');
       var lexer = new Lexer(input);
-      var result = lexer.getHexString('<');
+      var result = lexer.getHexString();
 
       expect(result).toEqual('p!U"$2');
     });