Reapply "Move the linter core to the analyzer package"

pkg/analyzer/lib/src/lint/util.dart

Index: pkg/analyzer/lib/src/lint/util.dart
diff --git a/pkg/analyzer/lib/src/lint/util.dart b/pkg/analyzer/lib/src/lint/util.dart
new file mode 100644
index 0000000000000000000000000000000000000000..e1c63af6a62eb1ec5fdcb3363a293cc91afe8e01
--- /dev/null
+++ b/pkg/analyzer/lib/src/lint/util.dart
@@ -0,0 +1,172 @@
+// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
+// for details. 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:io';
+
+import 'package:analyzer/analyzer.dart';
+import 'package:analyzer/dart/ast/token.dart';
+import 'package:analyzer/src/dart/ast/token.dart';
+import 'package:analyzer/src/dart/scanner/reader.dart';
+import 'package:analyzer/src/dart/scanner/scanner.dart';
+import 'package:analyzer/src/generated/parser.dart' show Parser;
+import 'package:analyzer/src/string_source.dart' show StringSource;
+import 'package:path/path.dart' as p;
+
+final _identifier = new RegExp(r'^([(_|$)a-zA-Z]+([_a-zA-Z0-9])*)$');
+
+final _lowerCamelCase =
+    new RegExp(r'^(_)*[?$a-z][a-z0-9?$]*([A-Z][a-z0-9?$]*)*$');
+
+final _lowerCaseUnderScore = new RegExp(r'^([a-z]+([_]?[a-z0-9]+)*)+$');
+
+final _lowerCaseUnderScoreWithDots =
+    new RegExp(r'^[a-z][_a-z0-9]*(\.[a-z][_a-z0-9]*)*$');
+
+final _pubspec = new RegExp(r'^[_]?pubspec\.yaml$');
+
+final _underscores = new RegExp(r'^[_]+$');
+
+/// Create a library name prefix based on [libraryPath], [projectRoot] and
+/// current [packageName].
+String createLibraryNamePrefix(
+    {String libraryPath, String projectRoot, String packageName}) {
+  // Use the posix context to canonicalize separators (`\`).
+  var libraryDirectory = p.posix.dirname(libraryPath);
+  var path = p.posix.relative(libraryDirectory, from: projectRoot);
+  // Drop 'lib/'.
+  var segments = p.split(path);
+  if (segments[0] == 'lib') {
+    path = p.posix.joinAll(segments.sublist(1));
+  }
+  // Replace separators.
+  path = path.replaceAll('/', '.');
+  // Add separator if needed.
+  if (path.isNotEmpty) {
+    path = '.$path';
+  }
+
+  return '$packageName$path';
+}
+
+/// Returns `true` if this [fileName] is a Dart file.
+bool isDartFileName(String fileName) => fileName.endsWith('.dart');
+
+/// Returns `true` if this [name] is a legal Dart identifier.
+bool isIdentifier(String name) => _identifier.hasMatch(name);
+
+/// Returns `true` of the given [name] is composed only of `_`s.
+bool isJustUnderscores(String name) => _underscores.hasMatch(name);
+
+/// Returns `true` if this [id] is `lowerCamelCase`.
+bool isLowerCamelCase(String id) =>
+    id.length == 1 && isUpperCase(id.codeUnitAt(0)) ||
+    id == '_' ||
+    _lowerCamelCase.hasMatch(id);
+
+/// Returns `true` if this [id] is `lower_camel_case_with_underscores`.
+bool isLowerCaseUnderScore(String id) => _lowerCaseUnderScore.hasMatch(id);
+
+/// Returns `true` if this [id] is `lower_camel_case_with_underscores_or.dots`.
+bool isLowerCaseUnderScoreWithDots(String id) =>
+    _lowerCaseUnderScoreWithDots.hasMatch(id);
+
+/// Returns `true` if this [fileName] is a Pubspec file.
+bool isPubspecFileName(String fileName) => _pubspec.hasMatch(fileName);
+
+/// Returns `true` if the given code unit [c] is upper case.
+bool isUpperCase(int c) => c >= 0x40 && c <= 0x5A;
+
+class Spelunker {
+  final String path;
+  final IOSink sink;
+  Spelunker(this.path, {IOSink sink}) : this.sink = sink ?? stdout;
+
+  void spelunk() {
+    var contents = new File(path).readAsStringSync();
+
+    var errorListener = new _ErrorListener();
+
+    var reader = new CharSequenceReader(contents);
+    var stringSource = new StringSource(contents, path);
+    var scanner = new Scanner(stringSource, reader, errorListener);
+    var startToken = scanner.tokenize();
+
+    errorListener.throwIfErrors();
+
+    var parser = new Parser(stringSource, errorListener);
+    var node = parser.parseCompilationUnit(startToken);
+
+    errorListener.throwIfErrors();
+
+    var visitor = new _SourceVisitor(sink);
+    node.accept(visitor);
+  }
+}
+
+class _ErrorListener implements AnalysisErrorListener {
+  final errors = <AnalysisError>[];
+
+  @override
+  void onError(AnalysisError error) {
+    errors.add(error);
+  }
+
+  void throwIfErrors() {
+    if (errors.isNotEmpty) {
+      throw new Exception(errors);
+    }
+  }
+}
+
+class _SourceVisitor extends GeneralizingAstVisitor {
+  int indent = 0;
+
+  final IOSink sink;
+  _SourceVisitor(this.sink);
+
+  String asString(AstNode node) =>
+      typeInfo(node.runtimeType) + ' [${node.toString()}]';
+
+  List<CommentToken> getPrecedingComments(Token token) {
+    var comments = <CommentToken>[];
+    var comment = token.precedingComments;
+    while (comment is CommentToken) {
+      comments.add(comment);
+      comment = comment.next;
+    }
+    return comments;
+  }
+
+  String getTrailingComment(AstNode node) {
+    var successor = node.endToken.next;
+    if (successor != null) {
+      var precedingComments = successor.precedingComments;
+      if (precedingComments != null) {
+        return precedingComments.toString();
+      }
+    }
+    return '';
+  }
+
+  String typeInfo(Type type) => type.toString();
+
+  @override
+  visitNode(AstNode node) {
+    write(node);
+
+    ++indent;
+    node.visitChildren(this);
+    --indent;
+    return null;
+  }
+
+  write(AstNode node) {
+    //EOL comments
+    var comments = getPrecedingComments(node.beginToken);
+    comments.forEach((c) => sink.writeln('${"  " * indent}$c'));
+
+    sink.writeln(
+        '${"  " * indent}${asString(node)} ${getTrailingComment(node)}');
+  }
+}