src/cobalt/debug/remote/devtools/node_modules/source-map/lib/source-map-generator.js - cobalt - Git at Google

 /* -*- Mode: js; js-indent-level: 2; -*- */
 /*
  * Copyright 2011 Mozilla Foundation and contributors
  * Licensed under the New BSD license. See LICENSE or:
  * http://opensource.org/licenses/BSD-3-Clause
  */

 var base64VLQ = require('./base64-vlq');
 var util = require('./util');
 var ArraySet = require('./array-set').ArraySet;
 var MappingList = require('./mapping-list').MappingList;

 /**
  * An instance of the SourceMapGenerator represents a source map which is
  * being built incrementally. You may pass an object with the following
  * properties:
  *
  *   - file: The filename of the generated source.
  *   - sourceRoot: A root for all relative URLs in this source map.
  */
 function SourceMapGenerator(aArgs) {
   if (!aArgs) {
     aArgs = {};
   }
   this._file = util.getArg(aArgs, 'file', null);
   this._sourceRoot = util.getArg(aArgs, 'sourceRoot', null);
   this._skipValidation = util.getArg(aArgs, 'skipValidation', false);
   this._sources = new ArraySet();
   this._names = new ArraySet();
   this._mappings = new MappingList();
   this._sourcesContents = null;
 }

 SourceMapGenerator.prototype._version = 3;

 /**
  * Creates a new SourceMapGenerator based on a SourceMapConsumer
  *
  * @param aSourceMapConsumer The SourceMap.
  */
 SourceMapGenerator.fromSourceMap =
   function SourceMapGenerator_fromSourceMap(aSourceMapConsumer) {
     var sourceRoot = aSourceMapConsumer.sourceRoot;
     var generator = new SourceMapGenerator({
       file: aSourceMapConsumer.file,
       sourceRoot: sourceRoot
     });
     aSourceMapConsumer.eachMapping(function (mapping) {
       var newMapping = {
         generated: {
           line: mapping.generatedLine,
           column: mapping.generatedColumn
         }
       };

       if (mapping.source != null) {
         newMapping.source = mapping.source;
         if (sourceRoot != null) {
           newMapping.source = util.relative(sourceRoot, newMapping.source);
         }

         newMapping.original = {
           line: mapping.originalLine,
           column: mapping.originalColumn
         };

         if (mapping.name != null) {
           newMapping.name = mapping.name;
         }
       }

       generator.addMapping(newMapping);
     });
     aSourceMapConsumer.sources.forEach(function (sourceFile) {
       var sourceRelative = sourceFile;
       if (sourceRoot !== null) {
         sourceRelative = util.relative(sourceRoot, sourceFile);
       }

       if (!generator._sources.has(sourceRelative)) {
         generator._sources.add(sourceRelative);
       }

       var content = aSourceMapConsumer.sourceContentFor(sourceFile);
       if (content != null) {
         generator.setSourceContent(sourceFile, content);
       }
     });
     return generator;
   };

 /**
  * Add a single mapping from original source line and column to the generated
  * source's line and column for this source map being created. The mapping
  * object should have the following properties:
  *
  *   - generated: An object with the generated line and column positions.
  *   - original: An object with the original line and column positions.
  *   - source: The original source file (relative to the sourceRoot).
  *   - name: An optional original token name for this mapping.
  */
 SourceMapGenerator.prototype.addMapping =
   function SourceMapGenerator_addMapping(aArgs) {
     var generated = util.getArg(aArgs, 'generated');
     var original = util.getArg(aArgs, 'original', null);
     var source = util.getArg(aArgs, 'source', null);
     var name = util.getArg(aArgs, 'name', null);

     if (!this._skipValidation) {
       this._validateMapping(generated, original, source, name);
     }

     if (source != null) {
       source = String(source);
       if (!this._sources.has(source)) {
         this._sources.add(source);
       }
     }

     if (name != null) {
       name = String(name);
       if (!this._names.has(name)) {
         this._names.add(name);
       }
     }

     this._mappings.add({
       generatedLine: generated.line,
       generatedColumn: generated.column,
       originalLine: original != null && original.line,
       originalColumn: original != null && original.column,
       source: source,
       name: name
     });
   };

 /**
  * Set the source content for a source file.
  */
 SourceMapGenerator.prototype.setSourceContent =
   function SourceMapGenerator_setSourceContent(aSourceFile, aSourceContent) {
     var source = aSourceFile;
     if (this._sourceRoot != null) {
       source = util.relative(this._sourceRoot, source);
     }

     if (aSourceContent != null) {
       // Add the source content to the _sourcesContents map.
       // Create a new _sourcesContents map if the property is null.
       if (!this._sourcesContents) {
         this._sourcesContents = Object.create(null);
       }
       this._sourcesContents[util.toSetString(source)] = aSourceContent;
     } else if (this._sourcesContents) {
       // Remove the source file from the _sourcesContents map.
       // If the _sourcesContents map is empty, set the property to null.
       delete this._sourcesContents[util.toSetString(source)];
       if (Object.keys(this._sourcesContents).length === 0) {
         this._sourcesContents = null;
       }
     }
   };

 /**
  * Applies the mappings of a sub-source-map for a specific source file to the
  * source map being generated. Each mapping to the supplied source file is
  * rewritten using the supplied source map. Note: The resolution for the
  * resulting mappings is the minimium of this map and the supplied map.
  *
  * @param aSourceMapConsumer The source map to be applied.
  * @param aSourceFile Optional. The filename of the source file.
  *        If omitted, SourceMapConsumer's file property will be used.
  * @param aSourceMapPath Optional. The dirname of the path to the source map
  *        to be applied. If relative, it is relative to the SourceMapConsumer.
  *        This parameter is needed when the two source maps aren't in the same
  *        directory, and the source map to be applied contains relative source
  *        paths. If so, those relative source paths need to be rewritten
  *        relative to the SourceMapGenerator.
  */
 SourceMapGenerator.prototype.applySourceMap =
   function SourceMapGenerator_applySourceMap(aSourceMapConsumer, aSourceFile, aSourceMapPath) {
     var sourceFile = aSourceFile;
     // If aSourceFile is omitted, we will use the file property of the SourceMap
     if (aSourceFile == null) {
       if (aSourceMapConsumer.file == null) {
         throw new Error(
           'SourceMapGenerator.prototype.applySourceMap requires either an explicit source file, ' +
           'or the source map\'s "file" property. Both were omitted.'
         );
       }
       sourceFile = aSourceMapConsumer.file;
     }
     var sourceRoot = this._sourceRoot;
     // Make "sourceFile" relative if an absolute Url is passed.
     if (sourceRoot != null) {
       sourceFile = util.relative(sourceRoot, sourceFile);
     }
     // Applying the SourceMap can add and remove items from the sources and
     // the names array.
     var newSources = new ArraySet();
     var newNames = new ArraySet();

     // Find mappings for the "sourceFile"
     this._mappings.unsortedForEach(function (mapping) {
       if (mapping.source === sourceFile && mapping.originalLine != null) {
         // Check if it can be mapped by the source map, then update the mapping.
         var original = aSourceMapConsumer.originalPositionFor({
           line: mapping.originalLine,
           column: mapping.originalColumn
         });
         if (original.source != null) {
           // Copy mapping
           mapping.source = original.source;
           if (aSourceMapPath != null) {
             mapping.source = util.join(aSourceMapPath, mapping.source)
           }
           if (sourceRoot != null) {
             mapping.source = util.relative(sourceRoot, mapping.source);
           }
           mapping.originalLine = original.line;
           mapping.originalColumn = original.column;
           if (original.name != null) {
             mapping.name = original.name;
           }
         }
       }

       var source = mapping.source;
       if (source != null && !newSources.has(source)) {
         newSources.add(source);
       }

       var name = mapping.name;
       if (name != null && !newNames.has(name)) {
         newNames.add(name);
       }

     }, this);
     this._sources = newSources;
     this._names = newNames;

     // Copy sourcesContents of applied map.
     aSourceMapConsumer.sources.forEach(function (sourceFile) {
       var content = aSourceMapConsumer.sourceContentFor(sourceFile);
       if (content != null) {
         if (aSourceMapPath != null) {
           sourceFile = util.join(aSourceMapPath, sourceFile);
         }
         if (sourceRoot != null) {
           sourceFile = util.relative(sourceRoot, sourceFile);
         }
         this.setSourceContent(sourceFile, content);
       }
     }, this);
   };

 /**
  * A mapping can have one of the three levels of data:
  *
  *   1. Just the generated position.
  *   2. The Generated position, original position, and original source.
  *   3. Generated and original position, original source, as well as a name
  *      token.
  *
  * To maintain consistency, we validate that any new mapping being added falls
  * in to one of these categories.
  */
 SourceMapGenerator.prototype._validateMapping =
   function SourceMapGenerator_validateMapping(aGenerated, aOriginal, aSource,
                                               aName) {
     // When aOriginal is truthy but has empty values for .line and .column,
     // it is most likely a programmer error. In this case we throw a very
     // specific error message to try to guide them the right way.
     // For example: https://github.com/Polymer/polymer-bundler/pull/519
     if (aOriginal && typeof aOriginal.line !== 'number' && typeof aOriginal.column !== 'number') {
         throw new Error(
             'original.line and original.column are not numbers -- you probably meant to omit ' +
             'the original mapping entirely and only map the generated position. If so, pass ' +
             'null for the original mapping instead of an object with empty or null values.'
         );
     }

     if (aGenerated && 'line' in aGenerated && 'column' in aGenerated
         && aGenerated.line > 0 && aGenerated.column >= 0
         && !aOriginal && !aSource && !aName) {
       // Case 1.
       return;
     }
     else if (aGenerated && 'line' in aGenerated && 'column' in aGenerated
              && aOriginal && 'line' in aOriginal && 'column' in aOriginal
              && aGenerated.line > 0 && aGenerated.column >= 0
              && aOriginal.line > 0 && aOriginal.column >= 0
              && aSource) {
       // Cases 2 and 3.
       return;
     }
     else {
       throw new Error('Invalid mapping: ' + JSON.stringify({
         generated: aGenerated,
         source: aSource,
         original: aOriginal,
         name: aName
       }));
     }
   };

 /**
  * Serialize the accumulated mappings in to the stream of base 64 VLQs
  * specified by the source map format.
  */
 SourceMapGenerator.prototype._serializeMappings =
   function SourceMapGenerator_serializeMappings() {
     var previousGeneratedColumn = 0;
     var previousGeneratedLine = 1;
     var previousOriginalColumn = 0;
     var previousOriginalLine = 0;
     var previousName = 0;
     var previousSource = 0;
     var result = '';
     var next;
     var mapping;
     var nameIdx;
     var sourceIdx;

     var mappings = this._mappings.toArray();
     for (var i = 0, len = mappings.length; i < len; i++) {
       mapping = mappings[i];
       next = ''

       if (mapping.generatedLine !== previousGeneratedLine) {
         previousGeneratedColumn = 0;
         while (mapping.generatedLine !== previousGeneratedLine) {
           next += ';';
           previousGeneratedLine++;
         }
       }
       else {
         if (i > 0) {
           if (!util.compareByGeneratedPositionsInflated(mapping, mappings[i - 1])) {
             continue;
           }
           next += ',';
         }
       }

       next += base64VLQ.encode(mapping.generatedColumn
                                  - previousGeneratedColumn);
       previousGeneratedColumn = mapping.generatedColumn;

       if (mapping.source != null) {
         sourceIdx = this._sources.indexOf(mapping.source);
         next += base64VLQ.encode(sourceIdx - previousSource);
         previousSource = sourceIdx;

         // lines are stored 0-based in SourceMap spec version 3
         next += base64VLQ.encode(mapping.originalLine - 1
                                    - previousOriginalLine);
         previousOriginalLine = mapping.originalLine - 1;

         next += base64VLQ.encode(mapping.originalColumn
                                    - previousOriginalColumn);
         previousOriginalColumn = mapping.originalColumn;

         if (mapping.name != null) {
           nameIdx = this._names.indexOf(mapping.name);
           next += base64VLQ.encode(nameIdx - previousName);
           previousName = nameIdx;
         }
       }

       result += next;
     }

     return result;
   };

 SourceMapGenerator.prototype._generateSourcesContent =
   function SourceMapGenerator_generateSourcesContent(aSources, aSourceRoot) {
     return aSources.map(function (source) {
       if (!this._sourcesContents) {
         return null;
       }
       if (aSourceRoot != null) {
         source = util.relative(aSourceRoot, source);
       }
       var key = util.toSetString(source);
       return Object.prototype.hasOwnProperty.call(this._sourcesContents, key)
         ? this._sourcesContents[key]
         : null;
     }, this);
   };

 /**
  * Externalize the source map.
  */
 SourceMapGenerator.prototype.toJSON =
   function SourceMapGenerator_toJSON() {
     var map = {
       version: this._version,
       sources: this._sources.toArray(),
       names: this._names.toArray(),
       mappings: this._serializeMappings()
     };
     if (this._file != null) {
       map.file = this._file;
     }
     if (this._sourceRoot != null) {
       map.sourceRoot = this._sourceRoot;
     }
     if (this._sourcesContents) {
       map.sourcesContent = this._generateSourcesContent(map.sources, map.sourceRoot);
     }

     return map;
   };

 /**
  * Render the source map being generated to a string.
  */
 SourceMapGenerator.prototype.toString =
   function SourceMapGenerator_toString() {
     return JSON.stringify(this.toJSON());
   };

 exports.SourceMapGenerator = SourceMapGenerator;
	/* -- Mode: js; js-indent-level: 2; -- */
	/*
	* Copyright 2011 Mozilla Foundation and contributors
	* Licensed under the New BSD license. See LICENSE or:
	* http://opensource.org/licenses/BSD-3-Clause
	*/

	var base64VLQ = require('./base64-vlq');
	var util = require('./util');
	var ArraySet = require('./array-set').ArraySet;
	var MappingList = require('./mapping-list').MappingList;

	/**
	* An instance of the SourceMapGenerator represents a source map which is
	* being built incrementally. You may pass an object with the following
	* properties:
	*
	* - file: The filename of the generated source.
	* - sourceRoot: A root for all relative URLs in this source map.
	*/
	function SourceMapGenerator(aArgs) {
	if (!aArgs) {
	aArgs = {};
	}
	this._file = util.getArg(aArgs, 'file', null);
	this._sourceRoot = util.getArg(aArgs, 'sourceRoot', null);
	this._skipValidation = util.getArg(aArgs, 'skipValidation', false);
	this._sources = new ArraySet();
	this._names = new ArraySet();
	this._mappings = new MappingList();
	this._sourcesContents = null;
	}

	SourceMapGenerator.prototype._version = 3;

	/**
	* Creates a new SourceMapGenerator based on a SourceMapConsumer
	*
	* @param aSourceMapConsumer The SourceMap.
	*/
	SourceMapGenerator.fromSourceMap =
	function SourceMapGenerator_fromSourceMap(aSourceMapConsumer) {
	var sourceRoot = aSourceMapConsumer.sourceRoot;
	var generator = new SourceMapGenerator({
	file: aSourceMapConsumer.file,
	sourceRoot: sourceRoot
	});
	aSourceMapConsumer.eachMapping(function (mapping) {
	var newMapping = {
	generated: {
	line: mapping.generatedLine,
	column: mapping.generatedColumn
	}
	};

	if (mapping.source != null) {
	newMapping.source = mapping.source;
	if (sourceRoot != null) {
	newMapping.source = util.relative(sourceRoot, newMapping.source);
	}

	newMapping.original = {
	line: mapping.originalLine,
	column: mapping.originalColumn
	};

	if (mapping.name != null) {
	newMapping.name = mapping.name;
	}
	}

	generator.addMapping(newMapping);
	});
	aSourceMapConsumer.sources.forEach(function (sourceFile) {
	var sourceRelative = sourceFile;
	if (sourceRoot !== null) {
	sourceRelative = util.relative(sourceRoot, sourceFile);
	}

	if (!generator._sources.has(sourceRelative)) {
	generator._sources.add(sourceRelative);
	}

	var content = aSourceMapConsumer.sourceContentFor(sourceFile);
	if (content != null) {
	generator.setSourceContent(sourceFile, content);
	}
	});
	return generator;
	};

	/**
	* Add a single mapping from original source line and column to the generated
	* source's line and column for this source map being created. The mapping
	* object should have the following properties:
	*
	* - generated: An object with the generated line and column positions.
	* - original: An object with the original line and column positions.
	* - source: The original source file (relative to the sourceRoot).
	* - name: An optional original token name for this mapping.
	*/
	SourceMapGenerator.prototype.addMapping =
	function SourceMapGenerator_addMapping(aArgs) {
	var generated = util.getArg(aArgs, 'generated');
	var original = util.getArg(aArgs, 'original', null);
	var source = util.getArg(aArgs, 'source', null);
	var name = util.getArg(aArgs, 'name', null);

	if (!this._skipValidation) {
	this._validateMapping(generated, original, source, name);
	}

	if (source != null) {
	source = String(source);
	if (!this._sources.has(source)) {
	this._sources.add(source);
	}
	}

	if (name != null) {
	name = String(name);
	if (!this._names.has(name)) {
	this._names.add(name);
	}
	}

	this._mappings.add({
	generatedLine: generated.line,
	generatedColumn: generated.column,
	originalLine: original != null && original.line,
	originalColumn: original != null && original.column,
	source: source,
	name: name
	});
	};

	/**
	* Set the source content for a source file.
	*/
	SourceMapGenerator.prototype.setSourceContent =
	function SourceMapGenerator_setSourceContent(aSourceFile, aSourceContent) {
	var source = aSourceFile;
	if (this._sourceRoot != null) {
	source = util.relative(this._sourceRoot, source);
	}

	if (aSourceContent != null) {
	// Add the source content to the _sourcesContents map.
	// Create a new _sourcesContents map if the property is null.
	if (!this._sourcesContents) {
	this._sourcesContents = Object.create(null);
	}
	this._sourcesContents[util.toSetString(source)] = aSourceContent;
	} else if (this._sourcesContents) {
	// Remove the source file from the _sourcesContents map.
	// If the _sourcesContents map is empty, set the property to null.
	delete this._sourcesContents[util.toSetString(source)];
	if (Object.keys(this._sourcesContents).length === 0) {
	this._sourcesContents = null;
	}
	}
	};

	/**
	* Applies the mappings of a sub-source-map for a specific source file to the
	* source map being generated. Each mapping to the supplied source file is
	* rewritten using the supplied source map. Note: The resolution for the
	* resulting mappings is the minimium of this map and the supplied map.
	*
	* @param aSourceMapConsumer The source map to be applied.
	* @param aSourceFile Optional. The filename of the source file.
	* If omitted, SourceMapConsumer's file property will be used.
	* @param aSourceMapPath Optional. The dirname of the path to the source map
	* to be applied. If relative, it is relative to the SourceMapConsumer.
	* This parameter is needed when the two source maps aren't in the same
	* directory, and the source map to be applied contains relative source
	* paths. If so, those relative source paths need to be rewritten
	* relative to the SourceMapGenerator.
	*/
	SourceMapGenerator.prototype.applySourceMap =
	function SourceMapGenerator_applySourceMap(aSourceMapConsumer, aSourceFile, aSourceMapPath) {
	var sourceFile = aSourceFile;
	// If aSourceFile is omitted, we will use the file property of the SourceMap
	if (aSourceFile == null) {
	if (aSourceMapConsumer.file == null) {
	throw new Error(
	'SourceMapGenerator.prototype.applySourceMap requires either an explicit source file, ' +
	'or the source map\'s "file" property. Both were omitted.'
	);
	}
	sourceFile = aSourceMapConsumer.file;
	}
	var sourceRoot = this._sourceRoot;
	// Make "sourceFile" relative if an absolute Url is passed.
	if (sourceRoot != null) {
	sourceFile = util.relative(sourceRoot, sourceFile);
	}
	// Applying the SourceMap can add and remove items from the sources and
	// the names array.
	var newSources = new ArraySet();
	var newNames = new ArraySet();

	// Find mappings for the "sourceFile"
	this._mappings.unsortedForEach(function (mapping) {
	if (mapping.source === sourceFile && mapping.originalLine != null) {
	// Check if it can be mapped by the source map, then update the mapping.
	var original = aSourceMapConsumer.originalPositionFor({
	line: mapping.originalLine,
	column: mapping.originalColumn
	});
	if (original.source != null) {
	// Copy mapping
	mapping.source = original.source;
	if (aSourceMapPath != null) {
	mapping.source = util.join(aSourceMapPath, mapping.source)
	}
	if (sourceRoot != null) {
	mapping.source = util.relative(sourceRoot, mapping.source);
	}
	mapping.originalLine = original.line;
	mapping.originalColumn = original.column;
	if (original.name != null) {
	mapping.name = original.name;
	}
	}
	}

	var source = mapping.source;
	if (source != null && !newSources.has(source)) {
	newSources.add(source);
	}

	var name = mapping.name;
	if (name != null && !newNames.has(name)) {
	newNames.add(name);
	}

	}, this);
	this._sources = newSources;
	this._names = newNames;

	// Copy sourcesContents of applied map.
	aSourceMapConsumer.sources.forEach(function (sourceFile) {
	var content = aSourceMapConsumer.sourceContentFor(sourceFile);
	if (content != null) {
	if (aSourceMapPath != null) {
	sourceFile = util.join(aSourceMapPath, sourceFile);
	}
	if (sourceRoot != null) {
	sourceFile = util.relative(sourceRoot, sourceFile);
	}
	this.setSourceContent(sourceFile, content);
	}
	}, this);
	};

	/**
	* A mapping can have one of the three levels of data:
	*
	* 1. Just the generated position.
	* 2. The Generated position, original position, and original source.
	* 3. Generated and original position, original source, as well as a name
	* token.
	*
	* To maintain consistency, we validate that any new mapping being added falls
	* in to one of these categories.
	*/
	SourceMapGenerator.prototype._validateMapping =
	function SourceMapGenerator_validateMapping(aGenerated, aOriginal, aSource,
	aName) {
	// When aOriginal is truthy but has empty values for .line and .column,
	// it is most likely a programmer error. In this case we throw a very
	// specific error message to try to guide them the right way.
	// For example: https://github.com/Polymer/polymer-bundler/pull/519
	if (aOriginal && typeof aOriginal.line !== 'number' && typeof aOriginal.column !== 'number') {
	throw new Error(
	'original.line and original.column are not numbers -- you probably meant to omit ' +
	'the original mapping entirely and only map the generated position. If so, pass ' +
	'null for the original mapping instead of an object with empty or null values.'
	);
	}

	if (aGenerated && 'line' in aGenerated && 'column' in aGenerated
	&& aGenerated.line > 0 && aGenerated.column >= 0
	&& !aOriginal && !aSource && !aName) {
	// Case 1.
	return;
	}
	else if (aGenerated && 'line' in aGenerated && 'column' in aGenerated
	&& aOriginal && 'line' in aOriginal && 'column' in aOriginal
	&& aGenerated.line > 0 && aGenerated.column >= 0
	&& aOriginal.line > 0 && aOriginal.column >= 0
	&& aSource) {
	// Cases 2 and 3.
	return;
	}
	else {
	throw new Error('Invalid mapping: ' + JSON.stringify({
	generated: aGenerated,
	source: aSource,
	original: aOriginal,
	name: aName
	}));
	}
	};

	/**
	* Serialize the accumulated mappings in to the stream of base 64 VLQs
	* specified by the source map format.
	*/
	SourceMapGenerator.prototype._serializeMappings =
	function SourceMapGenerator_serializeMappings() {
	var previousGeneratedColumn = 0;
	var previousGeneratedLine = 1;
	var previousOriginalColumn = 0;
	var previousOriginalLine = 0;
	var previousName = 0;
	var previousSource = 0;
	var result = '';
	var next;
	var mapping;
	var nameIdx;
	var sourceIdx;

	var mappings = this._mappings.toArray();
	for (var i = 0, len = mappings.length; i < len; i++) {
	mapping = mappings[i];
	next = ''

	if (mapping.generatedLine !== previousGeneratedLine) {
	previousGeneratedColumn = 0;
	while (mapping.generatedLine !== previousGeneratedLine) {
	next += ';';
	previousGeneratedLine++;
	}
	}
	else {
	if (i > 0) {
	if (!util.compareByGeneratedPositionsInflated(mapping, mappings[i - 1])) {
	continue;
	}
	next += ',';
	}
	}

	next += base64VLQ.encode(mapping.generatedColumn
	- previousGeneratedColumn);
	previousGeneratedColumn = mapping.generatedColumn;

	if (mapping.source != null) {
	sourceIdx = this._sources.indexOf(mapping.source);
	next += base64VLQ.encode(sourceIdx - previousSource);
	previousSource = sourceIdx;

	// lines are stored 0-based in SourceMap spec version 3
	next += base64VLQ.encode(mapping.originalLine - 1
	- previousOriginalLine);
	previousOriginalLine = mapping.originalLine - 1;

	next += base64VLQ.encode(mapping.originalColumn
	- previousOriginalColumn);
	previousOriginalColumn = mapping.originalColumn;

	if (mapping.name != null) {
	nameIdx = this._names.indexOf(mapping.name);
	next += base64VLQ.encode(nameIdx - previousName);
	previousName = nameIdx;
	}
	}

	result += next;
	}

	return result;
	};

	SourceMapGenerator.prototype._generateSourcesContent =
	function SourceMapGenerator_generateSourcesContent(aSources, aSourceRoot) {
	return aSources.map(function (source) {
	if (!this._sourcesContents) {
	return null;
	}
	if (aSourceRoot != null) {
	source = util.relative(aSourceRoot, source);
	}
	var key = util.toSetString(source);
	return Object.prototype.hasOwnProperty.call(this._sourcesContents, key)
	? this._sourcesContents[key]
	: null;
	}, this);
	};

	/**
	* Externalize the source map.
	*/
	SourceMapGenerator.prototype.toJSON =
	function SourceMapGenerator_toJSON() {
	var map = {
	version: this._version,
	sources: this._sources.toArray(),
	names: this._names.toArray(),
	mappings: this._serializeMappings()
	};
	if (this._file != null) {
	map.file = this._file;
	}
	if (this._sourceRoot != null) {
	map.sourceRoot = this._sourceRoot;
	}
	if (this._sourcesContents) {
	map.sourcesContent = this._generateSourcesContent(map.sources, map.sourceRoot);
	}

	return map;
	};

	/**
	* Render the source map being generated to a string.
	*/
	SourceMapGenerator.prototype.toString =
	function SourceMapGenerator_toString() {
	return JSON.stringify(this.toJSON());
	};

	exports.SourceMapGenerator = SourceMapGenerator;