Support code generation for other languages

pkg/analysis_server/tool/spec/codegen_tools.dart

 // Copyright (c) 2014, 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.
 
 /**
  * Tools for code generation.
  */
 library codegen.tools;
 
 import 'dart:io';
@@ skipping 37 matching lines @@
 /**
  * Type of functions used to compute the contents of a generated file.
  */
 typedef String FileContentsComputer();
 
 /**
  * Mixin class for generating code.
  */
 class CodeGenerator {
   _CodeGeneratorState _state;
+  // Defaults are good for generating Java and Dart source code.

[Paul Berry, 2015/01/23 19:28:59]

It's a little confusing to call this "defaults" since the settings can be
changed, and after they are changed, they won't be the default settings anymore
:)

How about this comment instead:

"Settings that specialize code generation behavior for a given programming
language"

Also, the comment should use Javadoc notation so that it will be picked up by
dartdoc.

[guillermooo, 2015/01/23 19:49:12]

Acknowledged.

+  CodeGeneratorSettings _settings = new CodeGeneratorSettings();
 
   /**
    * Measure the width of the current indentation level.
    */
   int get indentWidth => _state.nextIndent.length;
 
   /**
+   * Change code generation settings to adapt [CodeGenerator] to any

[Paul Berry, 2015/01/23 19:28:59]

Since we're allowing the client to change the settings arbitrarily, I'd prefer
to just remove this setter and rename "_settings" to some public name (e.g.
"codeGeneratorSettings").

[guillermooo, 2015/01/23 19:49:13]

Acknowledged.

+   * programming language.
+   */
+  void setCodeGeneratorSettings(CodeGeneratorSettings settings) {
+    _settings = settings;
+  }
+
+  /**
    * Execute [callback], collecting any code that is output using [write]
    * or [writeln], and return the result as a string.
    */
   String collectCode(void callback()) {
     _CodeGeneratorState oldState = _state;
     try {
       _state = new _CodeGeneratorState();
       callback();
       return _state.buffer.toString().replaceAll(trailingWhitespaceRegExp, '');
     } finally {
       _state = oldState;
     }
   }
 
   /**
    * Generate a doc comment based on the HTML in [docs].
    *
    * If [javadocStyle] is true, then the output is compatable with Javadoc,
    * which understands certain HTML constructs.
    */
-  void docComment(List<dom.Node> docs, {int width: 79, bool javadocStyle:
-      false}) {
+  void docComment(List<dom.Node> docs) {
     if (containsOnlyWhitespace(docs)) {
       return;
     }
-    writeln('/**');
-    indentBy(' * ', () {
+    writeln(_settings.docCommentStart);
+    var width = _settings.commentLineLength;
+    var javadocStyle = _settings.languageName == 'java';
+    indentBy(_settings.docCommentLineLeader, () {
       write(nodesToText(docs, width - _state.indent.length, javadocStyle));
     });
-    writeln(' */');
+    writeln(_settings.docCommentEnd);
+  }
+
+  void lineComment(List<dom.Node> docs) {
+    if (containsOnlyWhitespace(docs)) {
+      return;
+    }
+    write(_settings.lineCommentLineLeader);
+    var width = _settings.commentLineLength;
+    indentBy(_settings.lineCommentLineLeader, () {
+      write(nodesToText(docs, width - _state.indent.length, false));
+    });
   }
 
   /**
    * Execute [callback], indenting any code it outputs by two spaces.
    */
   void indent(void callback()) => indentSpecial('  ', '  ', callback);
 
   /**
    * Execute [callback], using [additionalIndent] to indent any code it outputs.
    */
@@ skipping 14 matching lines @@
       _state.indent += additionalIndent;
       callback();
     } finally {
       _state.nextIndent = oldNextIndent;
       _state.indent = oldIndent;
     }
   }
 
   void outputHeader({bool javaStyle: false}) {
     String header;
-    if (javaStyle) {
+    if (_settings.languageName == 'java') {
       header = '''
 /*
  * Copyright (c) 2014, the Dart project authors.
  * 
  * Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
  * 
  * http://www.eclipse.org/legal/epl-v10.html
  * 
  * Unless required by applicable law or agreed to in writing, software distributed under the License
  * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
  * or implied. See the License for the specific language governing permissions and limitations under
  * the License.
  * 
  * This file has been automatically generated.  Please do not edit it manually.
  * To regenerate the file, use the script "pkg/analysis_server/tool/spec/generate_files".
  */''';
+    } else if (_settings.languageName == 'python') {
+      header = '''
+# Copyright (c) 2014, 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.
+#
+# This file has been automatically generated.  Please do not edit it manually.
+# To regenerate the file, use the script
+# "pkg/analysis_server/tool/spec/generate_files".
+''';
     } else {
       header = '''
 // Copyright (c) 2014, 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.
 //
 // This file has been automatically generated.  Please do not edit it manually.
 // To regenerate the file, use the script
 // "pkg/analysis_server/tool/spec/generate_files".
 ''';
@@ skipping 234 matching lines @@
 
   /**
    * Output text, ending the current line.
    */
   void writeln([Object obj = '']) {
     _state.write('$obj\n');
   }
 }
 
 /**
+ * Controls several settings of [CodeGenerator].
+ *
+ * The default settings are valid for generating Java and Dart code.
+ */
+class CodeGeneratorSettings {
+  /**
+   * Name of the language being generated. Lowercase.
+   */
+  String languageName;
+
+  /**
+   * Marker used in line comments.
+   */
+  String lineCommentLineLeader;
+
+  /**
+   * Start marker for doc comments.
+   */
+  String docCommentStart;

[guillermooo, 2015/01/23 19:49:12]

Rename to docCommentStartMarker?

+
+  /**
+   * Line leader for body lines in doc comments.
+   */
+  String docCommentLineLeader;
+
+  /**
+   * End marker for doc comments.
+   */
+  String docCommentEnd;

[guillermooo, 2015/01/23 19:49:13]

Rename to docCommentEndMarker?

+
+  /**
+   * Line length for doc comment lines.
+   */
+  int commentLineLength;

[guillermooo, 2015/01/23 19:49:13]

Should we have a `commentLineLength` and `docCommentLineLength`?

+
+  CodeGeneratorSettings({this.languageName: 'java', this.lineCommentLineLeader: '// ',
+    this.docCommentStart: '/**', this.docCommentLineLeader: ' * ',
+    this.docCommentEnd: ' */', this.commentLineLength: 79});
+}
+
+/**
  * State used by [CodeGenerator].
  */
 class _CodeGeneratorState {
   StringBuffer buffer = new StringBuffer();
   String nextIndent = '';
   String indent = '';
   bool indentNeeded = true;
 
   void write(String text) {
     List<String> lines = text.split('\n');
@@ skipping 42 matching lines @@
     if (lines.last.isEmpty) {
       lines.removeLast();
       buffer.add(new dom.Text(lines.join('\n$indent') + '\n'));
       indentNeeded = true;
     } else {
       buffer.add(new dom.Text(lines.join('\n$indent')));
       indentNeeded = false;
     }
   }
 }