Source kind arg support for dartftmt.

pkg/analyzer/bin/formatter.dart

 #!/usr/bin/env dart
 
 // Copyright (c) 2013, 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:convert';
 import 'dart:io';
 
 import 'package:args/args.dart';
 import 'package:path/path.dart' as path;
 
 import 'package:analyzer/src/services/formatter_impl.dart';
 
 
 const BINARY_NAME = 'dartfmt';
 final dartFileRegExp = new RegExp(r'^[^.].*\.dart$', caseSensitive: false);
 final argParser = _initArgParser();
 final defaultSelection = new Selection(-1, -1);
 
 var formatterSettings;
 
+CodeKind kind;
 bool machineFormat;
 bool overwriteFileContents;
 Selection selection;
 const followLinks = false;
 
 
 main(args) {
   var options = argParser.parse(args);
   if (options['help']) {
     _printUsage();
     return;
   }
 
   _readOptions(options);
 
   if (options.rest.isEmpty) {
-    _formatStdin(options);
+    _formatStdin(kind);
   } else {
     _formatPaths(options.rest);
   }
 }
 
 _readOptions(options) {
+  kind = _parseKind(options['kind']);
   machineFormat = options['machine'];
   overwriteFileContents = options['write'];
   selection = _parseSelection(options['selection']);
   formatterSettings =
       new FormatterOptions(codeTransforms: options['transform']);
 }
 
+CodeKind _parseKind(kindOption) {
+  switch(kindOption) {
+    case 'stmt' :
+      return CodeKind.STATEMENT;
+    default:
+      return CodeKind.COMPILATION_UNIT;
+  }
+}
+
 Selection _parseSelection(selectionOption) {
   if (selectionOption != null) {
     var units = selectionOption.split(',');
     if (units.length == 2) {
       var offset = _toInt(units[0]);
       var length = _toInt(units[1]);
       if (offset != null && length != null) {
         return new Selection(offset, length);
       }
     }
@@ skipping 23 matching lines @@
 }
 
 _formatDirectory(dir) => dir.listSync(followLinks: followLinks)
     .forEach((resource) => _formatResource(resource));
 
 _formatFile(file) {
   if (_isDartFile(file)) {
     try {
       var buffer = new StringBuffer();
       var rawSource = file.readAsStringSync();
-      var formatted = _formatCU(rawSource);
+      var formatted = _format(rawSource, CodeKind.COMPILATION_UNIT);
       if (overwriteFileContents) {
         file.writeAsStringSync(formatted);
       } else {
         print(formatted);
       }
     } catch (e) {
       _log('Unable to format "${file.path}": $e');
     }
   }
 }
 
 _isDartFile(file) => dartFileRegExp.hasMatch(path.basename(file.path));
 
-_formatStdin(options) {
+_formatStdin(kind) {
   var input = new StringBuffer();
   stdin.transform(new Utf8Decoder())
       .listen((data) => input.write(data),
         onError: (error) => _log('Error reading from stdin'),
-        onDone: () => print(_formatCU(input.toString())));
+        onDone: () => print(_format(input.toString(), kind)));
 }
 
 /// Initialize the arg parser instance.
 ArgParser _initArgParser() {
   // NOTE: these flags are placeholders only!
   var parser = new ArgParser();
   parser.addFlag('write', abbr: 'w', negatable: false,
       help: 'Write reformatted sources to files (overwriting contents).  '
             'Do not print reformatted sources to standard output.');
+  parser.addOption('kind', abbr: 'k', defaultsTo: 'cu',
+      help: 'Specify source snippet kind ("stmt" or "cu")'
+            ' --- [PROVISIONAL API].');
   parser.addFlag('machine', abbr: 'm', negatable: false,
       help: 'Produce output in a format suitable for parsing.');
   parser.addOption('selection', abbr: 's',
       help: 'Specify selection information as an offset,length pair '
             '(e.g., -s "0,4").');
   parser.addFlag('transform', abbr: 't', negatable: true,
       help: 'Perform code transformations.');
   parser.addFlag('help', abbr: 'h', negatable: false,
       help: 'Print this usage information.');
   return parser;
@@ skipping 11 matching lines @@
                 'recursively. (Files starting with a period are ignored.) By '
                 'default, $BINARY_NAME prints the reformatted sources to '
                 'standard output.')
         ..write('\n\n')
         ..write('Supported flags are:')
         ..write('Usage: $BINARY_NAME [flags] [path...]\n\n')
         ..write('${argParser.getUsage()}\n\n');
   _log(buffer.toString());
 }
 
-/// Format the given [src] as a compilation unit.
-String _formatCU(src) {
+/// Format this [src], treating it as the given snippet [kind].
+String _format(src, kind) {
   var formatResult = new CodeFormatter(formatterSettings).format(
-      CodeKind.COMPILATION_UNIT, src, selection: selection);
+      kind, src, selection: selection);
   if (machineFormat) {
     if (formatResult.selection == null) {
       formatResult.selection = defaultSelection;
     }
     return _toJson(formatResult);
   }
   return formatResult.source;
 }
 
 _toJson(formatResult) =>
     // Actual JSON format TBD
     JSON.encode({'source': formatResult.source,
                  'selection': {
                      'offset': formatResult.selection.offset,
                      'length': formatResult.selection.length
                   }
     });
 
 /// Log the given [msg].
 _log(String msg) {
   //TODO(pquitslund): add proper log support
   print(msg);
 }