dev/snippets/lib/src/import_sorter.dart - mirrors/flutter - Git at Google

 // Copyright 2014 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 import 'dart:math';

 import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/dart/analysis/results.dart';
 import 'package:analyzer/dart/analysis/utilities.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/source/line_info.dart';
 import 'package:meta/meta.dart';

 import 'util.dart';

 /// Read the given source code, and return the new contents after sorting the
 /// imports.
 String sortImports(String contents) {
   final ParseStringResult parseResult = parseString(
     content: contents,
     featureSet: FeatureSet.fromEnableFlags2(
       sdkLanguageVersion: FlutterInformation.instance.getDartSdkVersion(),
       flags: <String>[],
     ),
   );
   final List<AnalysisError> errors = <AnalysisError>[];
   final _ImportOrganizer organizer =
       _ImportOrganizer(contents, parseResult.unit, errors);
   final List<_SourceEdit> edits = organizer.organize();
   // Sort edits in reverse order
   edits.sort((_SourceEdit a, _SourceEdit b) {
     return b.offset.compareTo(a.offset);
   });
   // Apply edits
   for (final _SourceEdit edit in edits) {
     contents = contents.replaceRange(edit.offset, edit.end, edit.replacement);
   }
   return contents;
 }

 /// Organizer of imports (and other directives) in the [unit].
 // Adapted from the analysis_server package.
 // This code is largely copied from:
 // https://github.com/dart-lang/sdk/blob/c7405b9d86b4b47cf7610667491f1db72723b0dd/pkg/analysis_server/lib/src/services/correction/organize_imports.dart#L15
 // TODO(gspencergoog): If ImportOrganizer ever becomes part of the public API,
 // this class should probably be replaced.
 // https://github.com/flutter/flutter/issues/86197
 class _ImportOrganizer {
   _ImportOrganizer(this.initialCode, this.unit, this.errors)
       : code = initialCode {
     endOfLine = getEOL(code);
     hasUnresolvedIdentifierError = errors.any((AnalysisError error) {
       return error.errorCode.isUnresolvedIdentifier;
     });
   }

   final String initialCode;

   final CompilationUnit unit;

   final List<AnalysisError> errors;

   String code;

   String endOfLine = '\n';

   bool hasUnresolvedIdentifierError = false;

   /// Returns the number of characters common to the end of [a] and [b].
   int findCommonSuffix(String a, String b) {
     final int aLength = a.length;
     final int bLength = b.length;
     final int n = min(aLength, bLength);
     for (int i = 1; i <= n; i++) {
       if (a.codeUnitAt(aLength - i) != b.codeUnitAt(bLength - i)) {
         return i - 1;
       }
     }
     return n;
   }

   /// Return the [_SourceEdit]s that organize imports in the [unit].
   List<_SourceEdit> organize() {
     _organizeDirectives();
     // prepare edits
     final List<_SourceEdit> edits = <_SourceEdit>[];
     if (code != initialCode) {
       final int suffixLength = findCommonSuffix(initialCode, code);
       final _SourceEdit edit = _SourceEdit(0, initialCode.length - suffixLength,
           code.substring(0, code.length - suffixLength));
       edits.add(edit);
     }
     return edits;
   }

   /// Organize all [Directive]s.
   void _organizeDirectives() {
     final LineInfo lineInfo = unit.lineInfo;
     bool hasLibraryDirective = false;
     final List<_DirectiveInfo> directives = <_DirectiveInfo>[];
     for (final Directive directive in unit.directives) {
       if (directive is LibraryDirective) {
         hasLibraryDirective = true;
       }
       if (directive is UriBasedDirective) {
         final _DirectivePriority? priority = getDirectivePriority(directive);
         if (priority != null) {
           int offset = directive.offset;
           int end = directive.end;

           final Token? leadingComment =
               getLeadingComment(unit, directive, lineInfo);
           final Token? trailingComment =
               getTrailingComment(unit, directive, lineInfo, end);

           String? leadingCommentText;
           if (leadingComment != null) {
             leadingCommentText =
                 code.substring(leadingComment.offset, directive.offset);
             offset = leadingComment.offset;
           }
           String? trailingCommentText;
           if (trailingComment != null) {
             trailingCommentText =
                 code.substring(directive.end, trailingComment.end);
             end = trailingComment.end;
           }
           String? documentationText;
           final Comment? documentationComment = directive.documentationComment;
           if (documentationComment != null) {
             documentationText = code.substring(
                 documentationComment.offset, documentationComment.end);
           }
           String? annotationText;
           final Token? beginToken = directive.metadata.beginToken;
           final Token? endToken = directive.metadata.endToken;
           if (beginToken != null && endToken != null) {
             annotationText = code.substring(beginToken.offset, endToken.end);
           }
           final String text = code.substring(
               directive.firstTokenAfterCommentAndMetadata.offset,
               directive.end);
           final String uriContent = directive.uri.stringValue ?? '';
           directives.add(
             _DirectiveInfo(
               directive,
               priority,
               leadingCommentText,
               documentationText,
               annotationText,
               uriContent,
               trailingCommentText,
               offset,
               end,
               text,
             ),
           );
         }
       }
     }
     // nothing to do
     if (directives.isEmpty) {
       return;
     }
     final int firstDirectiveOffset = directives.first.offset;
     final int lastDirectiveEnd = directives.last.end;

     // Without a library directive, the library comment is the comment of the
     // first directive.
     _DirectiveInfo? libraryDocumentationDirective;
     if (!hasLibraryDirective && directives.isNotEmpty) {
       libraryDocumentationDirective = directives.first;
     }

     // sort
     directives.sort();
     // append directives with grouping
     String directivesCode;
     {
       final StringBuffer sb = StringBuffer();
       if (libraryDocumentationDirective != null &&
           libraryDocumentationDirective.documentationText != null) {
         sb.write(libraryDocumentationDirective.documentationText);
         sb.write(endOfLine);
       }
       _DirectivePriority currentPriority = directives.first.priority;
       for (final _DirectiveInfo directiveInfo in directives) {
         if (currentPriority != directiveInfo.priority) {
           sb.write(endOfLine);
           currentPriority = directiveInfo.priority;
         }
         if (directiveInfo.leadingCommentText != null) {
           sb.write(directiveInfo.leadingCommentText);
         }
         if (directiveInfo != libraryDocumentationDirective &&
             directiveInfo.documentationText != null) {
           sb.write(directiveInfo.documentationText);
           sb.write(endOfLine);
         }
         if (directiveInfo.annotationText != null) {
           sb.write(directiveInfo.annotationText);
           sb.write(endOfLine);
         }
         sb.write(directiveInfo.text);
         if (directiveInfo.trailingCommentText != null) {
           sb.write(directiveInfo.trailingCommentText);
         }
         sb.write(endOfLine);
       }
       directivesCode = sb.toString();
       directivesCode = directivesCode.trimRight();
     }
     // prepare code
     final String beforeDirectives = code.substring(0, firstDirectiveOffset);
     final String afterDirectives = code.substring(lastDirectiveEnd);
     code = beforeDirectives + directivesCode + afterDirectives;
   }

   static _DirectivePriority? getDirectivePriority(UriBasedDirective directive) {
     final String uriContent = directive.uri.stringValue ?? '';
     if (directive is ImportDirective) {
       if (uriContent.startsWith('dart:')) {
         return _DirectivePriority.IMPORT_SDK;
       } else if (uriContent.startsWith('package:')) {
         return _DirectivePriority.IMPORT_PKG;
       } else if (uriContent.contains('://')) {
         return _DirectivePriority.IMPORT_OTHER;
       } else {
         return _DirectivePriority.IMPORT_REL;
       }
     }
     if (directive is ExportDirective) {
       if (uriContent.startsWith('dart:')) {
         return _DirectivePriority.EXPORT_SDK;
       } else if (uriContent.startsWith('package:')) {
         return _DirectivePriority.EXPORT_PKG;
       } else if (uriContent.contains('://')) {
         return _DirectivePriority.EXPORT_OTHER;
       } else {
         return _DirectivePriority.EXPORT_REL;
       }
     }
     if (directive is PartDirective) {
       return _DirectivePriority.PART;
     }
     return null;
   }

   /// Return the EOL to use for [code].
   static String getEOL(String code) {
     if (code.contains('\r\n')) {
       return '\r\n';
     } else {
       return '\n';
     }
   }

   /// Gets the first comment token considered to be the leading comment for this
   /// directive.
   ///
   /// Leading comments for the first directive in a file are considered library
   /// comments and not returned unless they contain blank lines, in which case
   /// only the last part of the comment will be returned.
   static Token? getLeadingComment(
       CompilationUnit unit, UriBasedDirective directive, LineInfo lineInfo) {
     if (directive.beginToken.precedingComments == null) {
       return null;
     }

     Token? firstComment = directive.beginToken.precedingComments;
     Token? comment = firstComment;
     Token? nextComment = comment?.next;
     // Don't connect comments that have a blank line between them
     while (comment != null && nextComment != null) {
       final int currentLine = lineInfo.getLocation(comment.offset).lineNumber;
       final int nextLine = lineInfo.getLocation(nextComment.offset).lineNumber;
       if (nextLine - currentLine > 1) {
         firstComment = nextComment;
       }
       comment = nextComment;
       nextComment = comment.next;
     }

     // Check if the comment is the first comment in the document
     if (firstComment != unit.beginToken.precedingComments) {
       final int previousDirectiveLine =
           lineInfo.getLocation(directive.beginToken.previous!.end).lineNumber;

       // Skip over any comments on the same line as the previous directive
       // as they will be attached to the end of it.
       Token? comment = firstComment;
       while (comment != null &&
           previousDirectiveLine ==
               lineInfo.getLocation(comment.offset).lineNumber) {
         comment = comment.next;
       }
       return comment;
     }
     return null;
   }

   /// Gets the last comment token considered to be the trailing comment for this
   /// directive.
   ///
   /// To be considered a trailing comment, the comment must be on the same line
   /// as the directive.
   static Token? getTrailingComment(CompilationUnit unit,
       UriBasedDirective directive, LineInfo lineInfo, int end) {
     final int line = lineInfo.getLocation(end).lineNumber;
     Token? comment = directive.endToken.next!.precedingComments;
     while (comment != null) {
       if (lineInfo.getLocation(comment.offset).lineNumber == line) {
         return comment;
       }
       comment = comment.next;
     }
     return null;
   }
 }

 class _DirectiveInfo implements Comparable<_DirectiveInfo> {
   _DirectiveInfo(
     this.directive,
     this.priority,
     this.leadingCommentText,
     this.documentationText,
     this.annotationText,
     this.uri,
     this.trailingCommentText,
     this.offset,
     this.end,
     this.text,
   );

   final UriBasedDirective directive;
   final _DirectivePriority priority;
   final String? leadingCommentText;
   final String? documentationText;
   final String? annotationText;
   final String uri;
   final String? trailingCommentText;

   /// The offset of the first token, usually the keyword but may include leading comments.
   final int offset;

   /// The offset after the last token, including the end-of-line comment.
   final int end;

   /// The text excluding comments, documentation and annotations.
   final String text;

   @override
   int compareTo(_DirectiveInfo other) {
     if (priority == other.priority) {
       return _compareUri(uri, other.uri);
     }
     return priority.index - other.priority.index;
   }

   @override
   String toString() => '(priority=$priority; text=$text)';

   static int _compareUri(String a, String b) {
     final List<String> aList = _splitUri(a);
     final List<String> bList = _splitUri(b);
     int result;
     if ((result = aList[0].compareTo(bList[0])) != 0) {
       return result;
     }
     if ((result = aList[1].compareTo(bList[1])) != 0) {
       return result;
     }
     return 0;
   }

   /// Split the given [uri] like `package:some.name/and/path.dart` into a list
   /// like `[package:some.name, and/path.dart]`.
   static List<String> _splitUri(String uri) {
     final int index = uri.indexOf('/');
     if (index == -1) {
       return <String>[uri, ''];
     }
     return <String>[uri.substring(0, index), uri.substring(index + 1)];
   }
 }

 enum _DirectivePriority {
   IMPORT_SDK,
   IMPORT_PKG,
   IMPORT_OTHER,
   IMPORT_REL,
   EXPORT_SDK,
   EXPORT_PKG,
   EXPORT_OTHER,
   EXPORT_REL,
   PART
 }

 /// SourceEdit
 ///
 /// {
 ///   "offset": int
 ///   "length": int
 ///   "replacement": String
 ///   "id": optional String
 /// }
 ///
 /// Clients may not extend, implement or mix-in this class.
 @immutable
 class _SourceEdit {
   const _SourceEdit(this.offset, this.length, this.replacement);

   /// The offset of the region to be modified.
   final int offset;

   /// The length of the region to be modified.
   final int length;

   /// The end of the region to be modified.
   int get end => offset + length;

   /// The code that is to replace the specified region in the original code.
   final String replacement;
 }
	// Copyright 2014 The Flutter Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	import 'dart:math';

	import 'package:analyzer/dart/analysis/features.dart';
	import 'package:analyzer/dart/analysis/results.dart';
	import 'package:analyzer/dart/analysis/utilities.dart';
	import 'package:analyzer/dart/ast/ast.dart';
	import 'package:analyzer/dart/ast/token.dart';
	import 'package:analyzer/error/error.dart';
	import 'package:analyzer/source/line_info.dart';
	import 'package:meta/meta.dart';

	import 'util.dart';

	/// Read the given source code, and return the new contents after sorting the
	/// imports.
	String sortImports(String contents) {
	final ParseStringResult parseResult = parseString(
	content: contents,
	featureSet: FeatureSet.fromEnableFlags2(
	sdkLanguageVersion: FlutterInformation.instance.getDartSdkVersion(),
	flags: <String>[],
	),
	);
	final List<AnalysisError> errors = <AnalysisError>[];
	final _ImportOrganizer organizer =
	_ImportOrganizer(contents, parseResult.unit, errors);
	final List<_SourceEdit> edits = organizer.organize();
	// Sort edits in reverse order
	edits.sort((_SourceEdit a, _SourceEdit b) {
	return b.offset.compareTo(a.offset);
	});
	// Apply edits
	for (final _SourceEdit edit in edits) {
	contents = contents.replaceRange(edit.offset, edit.end, edit.replacement);
	}
	return contents;
	}

	/// Organizer of imports (and other directives) in the [unit].
	// Adapted from the analysis_server package.
	// This code is largely copied from:
	// https://github.com/dart-lang/sdk/blob/c7405b9d86b4b47cf7610667491f1db72723b0dd/pkg/analysis_server/lib/src/services/correction/organize_imports.dart#L15
	// TODO(gspencergoog): If ImportOrganizer ever becomes part of the public API,
	// this class should probably be replaced.
	// https://github.com/flutter/flutter/issues/86197
	class _ImportOrganizer {
	_ImportOrganizer(this.initialCode, this.unit, this.errors)
	: code = initialCode {
	endOfLine = getEOL(code);
	hasUnresolvedIdentifierError = errors.any((AnalysisError error) {
	return error.errorCode.isUnresolvedIdentifier;
	});
	}

	final String initialCode;

	final CompilationUnit unit;

	final List<AnalysisError> errors;

	String code;

	String endOfLine = '\n';

	bool hasUnresolvedIdentifierError = false;

	/// Returns the number of characters common to the end of [a] and [b].
	int findCommonSuffix(String a, String b) {
	final int aLength = a.length;
	final int bLength = b.length;
	final int n = min(aLength, bLength);
	for (int i = 1; i <= n; i++) {
	if (a.codeUnitAt(aLength - i) != b.codeUnitAt(bLength - i)) {
	return i - 1;
	}
	}
	return n;
	}

	/// Return the [_SourceEdit]s that organize imports in the [unit].
	List<_SourceEdit> organize() {
	_organizeDirectives();
	// prepare edits
	final List<_SourceEdit> edits = <_SourceEdit>[];
	if (code != initialCode) {
	final int suffixLength = findCommonSuffix(initialCode, code);
	final _SourceEdit edit = _SourceEdit(0, initialCode.length - suffixLength,
	code.substring(0, code.length - suffixLength));
	edits.add(edit);
	}
	return edits;
	}

	/// Organize all [Directive]s.
	void _organizeDirectives() {
	final LineInfo lineInfo = unit.lineInfo;
	bool hasLibraryDirective = false;
	final List<_DirectiveInfo> directives = <_DirectiveInfo>[];
	for (final Directive directive in unit.directives) {
	if (directive is LibraryDirective) {
	hasLibraryDirective = true;
	}
	if (directive is UriBasedDirective) {
	final _DirectivePriority? priority = getDirectivePriority(directive);
	if (priority != null) {
	int offset = directive.offset;
	int end = directive.end;

	final Token? leadingComment =
	getLeadingComment(unit, directive, lineInfo);
	final Token? trailingComment =
	getTrailingComment(unit, directive, lineInfo, end);

	String? leadingCommentText;
	if (leadingComment != null) {
	leadingCommentText =
	code.substring(leadingComment.offset, directive.offset);
	offset = leadingComment.offset;
	}
	String? trailingCommentText;
	if (trailingComment != null) {
	trailingCommentText =
	code.substring(directive.end, trailingComment.end);
	end = trailingComment.end;
	}
	String? documentationText;
	final Comment? documentationComment = directive.documentationComment;
	if (documentationComment != null) {
	documentationText = code.substring(
	documentationComment.offset, documentationComment.end);
	}
	String? annotationText;
	final Token? beginToken = directive.metadata.beginToken;
	final Token? endToken = directive.metadata.endToken;
	if (beginToken != null && endToken != null) {
	annotationText = code.substring(beginToken.offset, endToken.end);
	}
	final String text = code.substring(
	directive.firstTokenAfterCommentAndMetadata.offset,
	directive.end);
	final String uriContent = directive.uri.stringValue ?? '';
	directives.add(
	_DirectiveInfo(
	directive,
	priority,
	leadingCommentText,
	documentationText,
	annotationText,
	uriContent,
	trailingCommentText,
	offset,
	end,
	text,
	),
	);
	}
	}
	}
	// nothing to do
	if (directives.isEmpty) {
	return;
	}
	final int firstDirectiveOffset = directives.first.offset;
	final int lastDirectiveEnd = directives.last.end;

	// Without a library directive, the library comment is the comment of the
	// first directive.
	_DirectiveInfo? libraryDocumentationDirective;
	if (!hasLibraryDirective && directives.isNotEmpty) {
	libraryDocumentationDirective = directives.first;
	}

	// sort
	directives.sort();
	// append directives with grouping
	String directivesCode;
	{
	final StringBuffer sb = StringBuffer();
	if (libraryDocumentationDirective != null &&
	libraryDocumentationDirective.documentationText != null) {
	sb.write(libraryDocumentationDirective.documentationText);
	sb.write(endOfLine);
	}
	_DirectivePriority currentPriority = directives.first.priority;
	for (final _DirectiveInfo directiveInfo in directives) {
	if (currentPriority != directiveInfo.priority) {
	sb.write(endOfLine);
	currentPriority = directiveInfo.priority;
	}
	if (directiveInfo.leadingCommentText != null) {
	sb.write(directiveInfo.leadingCommentText);
	}
	if (directiveInfo != libraryDocumentationDirective &&
	directiveInfo.documentationText != null) {
	sb.write(directiveInfo.documentationText);
	sb.write(endOfLine);
	}
	if (directiveInfo.annotationText != null) {
	sb.write(directiveInfo.annotationText);
	sb.write(endOfLine);
	}
	sb.write(directiveInfo.text);
	if (directiveInfo.trailingCommentText != null) {
	sb.write(directiveInfo.trailingCommentText);
	}
	sb.write(endOfLine);
	}
	directivesCode = sb.toString();
	directivesCode = directivesCode.trimRight();
	}
	// prepare code
	final String beforeDirectives = code.substring(0, firstDirectiveOffset);
	final String afterDirectives = code.substring(lastDirectiveEnd);
	code = beforeDirectives + directivesCode + afterDirectives;
	}

	static _DirectivePriority? getDirectivePriority(UriBasedDirective directive) {
	final String uriContent = directive.uri.stringValue ?? '';
	if (directive is ImportDirective) {
	if (uriContent.startsWith('dart:')) {
	return _DirectivePriority.IMPORT_SDK;
	} else if (uriContent.startsWith('package:')) {
	return _DirectivePriority.IMPORT_PKG;
	} else if (uriContent.contains('://')) {
	return _DirectivePriority.IMPORT_OTHER;
	} else {
	return _DirectivePriority.IMPORT_REL;
	}
	}
	if (directive is ExportDirective) {
	if (uriContent.startsWith('dart:')) {
	return _DirectivePriority.EXPORT_SDK;
	} else if (uriContent.startsWith('package:')) {
	return _DirectivePriority.EXPORT_PKG;
	} else if (uriContent.contains('://')) {
	return _DirectivePriority.EXPORT_OTHER;
	} else {
	return _DirectivePriority.EXPORT_REL;
	}
	}
	if (directive is PartDirective) {
	return _DirectivePriority.PART;
	}
	return null;
	}

	/// Return the EOL to use for [code].
	static String getEOL(String code) {
	if (code.contains('\r\n')) {
	return '\r\n';
	} else {
	return '\n';
	}
	}

	/// Gets the first comment token considered to be the leading comment for this
	/// directive.
	///
	/// Leading comments for the first directive in a file are considered library
	/// comments and not returned unless they contain blank lines, in which case
	/// only the last part of the comment will be returned.
	static Token? getLeadingComment(
	CompilationUnit unit, UriBasedDirective directive, LineInfo lineInfo) {
	if (directive.beginToken.precedingComments == null) {
	return null;
	}

	Token? firstComment = directive.beginToken.precedingComments;
	Token? comment = firstComment;
	Token? nextComment = comment?.next;
	// Don't connect comments that have a blank line between them
	while (comment != null && nextComment != null) {
	final int currentLine = lineInfo.getLocation(comment.offset).lineNumber;
	final int nextLine = lineInfo.getLocation(nextComment.offset).lineNumber;
	if (nextLine - currentLine > 1) {
	firstComment = nextComment;
	}
	comment = nextComment;
	nextComment = comment.next;
	}

	// Check if the comment is the first comment in the document
	if (firstComment != unit.beginToken.precedingComments) {
	final int previousDirectiveLine =
	lineInfo.getLocation(directive.beginToken.previous!.end).lineNumber;

	// Skip over any comments on the same line as the previous directive
	// as they will be attached to the end of it.
	Token? comment = firstComment;
	while (comment != null &&
	previousDirectiveLine ==
	lineInfo.getLocation(comment.offset).lineNumber) {
	comment = comment.next;
	}
	return comment;
	}
	return null;
	}

	/// Gets the last comment token considered to be the trailing comment for this
	/// directive.
	///
	/// To be considered a trailing comment, the comment must be on the same line
	/// as the directive.
	static Token? getTrailingComment(CompilationUnit unit,
	UriBasedDirective directive, LineInfo lineInfo, int end) {
	final int line = lineInfo.getLocation(end).lineNumber;
	Token? comment = directive.endToken.next!.precedingComments;
	while (comment != null) {
	if (lineInfo.getLocation(comment.offset).lineNumber == line) {
	return comment;
	}
	comment = comment.next;
	}
	return null;
	}
	}

	class _DirectiveInfo implements Comparable<_DirectiveInfo> {
	_DirectiveInfo(
	this.directive,
	this.priority,
	this.leadingCommentText,
	this.documentationText,
	this.annotationText,
	this.uri,
	this.trailingCommentText,
	this.offset,
	this.end,
	this.text,
	);

	final UriBasedDirective directive;
	final _DirectivePriority priority;
	final String? leadingCommentText;
	final String? documentationText;
	final String? annotationText;
	final String uri;
	final String? trailingCommentText;

	/// The offset of the first token, usually the keyword but may include leading comments.
	final int offset;

	/// The offset after the last token, including the end-of-line comment.
	final int end;

	/// The text excluding comments, documentation and annotations.
	final String text;

	@override
	int compareTo(_DirectiveInfo other) {
	if (priority == other.priority) {
	return _compareUri(uri, other.uri);
	}
	return priority.index - other.priority.index;
	}

	@override
	String toString() => '(priority=$priority; text=$text)';

	static int _compareUri(String a, String b) {
	final List<String> aList = _splitUri(a);
	final List<String> bList = _splitUri(b);
	int result;
	if ((result = aList[0].compareTo(bList[0])) != 0) {
	return result;
	}
	if ((result = aList[1].compareTo(bList[1])) != 0) {
	return result;
	}
	return 0;
	}

	/// Split the given [uri] like `package:some.name/and/path.dart` into a list
	/// like `[package:some.name, and/path.dart]`.
	static List<String> _splitUri(String uri) {
	final int index = uri.indexOf('/');
	if (index == -1) {
	return <String>[uri, ''];
	}
	return <String>[uri.substring(0, index), uri.substring(index + 1)];
	}
	}

	enum _DirectivePriority {
	IMPORT_SDK,
	IMPORT_PKG,
	IMPORT_OTHER,
	IMPORT_REL,
	EXPORT_SDK,
	EXPORT_PKG,
	EXPORT_OTHER,
	EXPORT_REL,
	PART
	}

	/// SourceEdit
	///
	/// {
	/// "offset": int
	/// "length": int
	/// "replacement": String
	/// "id": optional String
	/// }
	///
	/// Clients may not extend, implement or mix-in this class.
	@immutable
	class _SourceEdit {
	const _SourceEdit(this.offset, this.length, this.replacement);

	/// The offset of the region to be modified.
	final int offset;

	/// The length of the region to be modified.
	final int length;

	/// The end of the region to be modified.
	int get end => offset + length;

	/// The code that is to replace the specified region in the original code.
	final String replacement;
	}