leg pad (similar to frogpad, but for leg)

tools/testing/legpad/legpad.dart

Index: tools/testing/legpad/legpad.dart
diff --git a/tools/testing/legpad/legpad.dart b/tools/testing/legpad/legpad.dart
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+// Copyright (c) 2012, 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:html", prefix:"html");
+#import('../../../frog/leg/api.dart', prefix: "api_lib");
+#import('../../../lib/uri/uri.dart', prefix:"uri_lib");
+
+/**
+ * This is the entrypoint for a version of the leg compiler that
+ * runs in the browser.
+ *
+ * Because this is running in the browser, we do not access
+ * the file system.  Instead, we assume that all necessary files
+ * have been placed in inert <script> elements somewhere on the html page.
+ *
+ * (See legpad.py for more details on how the html page is constructed.)
+ */
+void main() {
+  new Legpad().go();
+}
+
+class Legpad {
+  // id of script element containing name of the main dart file

[floitsch, 2012/03/26 22:07:05]

Id and finish sentence with '.'.

+  // to compile

[floitsch, 2012/03/26 22:07:05]

Unless I'm wrong this is the Id of the script element that contains the code
that should be compiled (no files involved).

[mattsh, 2012/03/27 02:30:25]

(just chatted offline, yes, this is in fact the file name)

+  static final String MAIN_ID = "main_id";
+
+  // accumulates diagnostic messages emitted by the leg compiler

[floitsch, 2012/03/26 22:07:05]

ditto: start with uppercase and finish with '.'.

+  String warnings = "";

[floitsch, 2012/03/26 22:07:05]

Make it a StringBuffer?

[mattsh, 2012/03/27 02:30:25]

Done.

+
+  // the generated javascript
+  String output;
+
+  String readAll(String filename) {
+    // TODO - currently leg is confused about where these two files

[floitsch, 2012/03/26 22:07:05]

TODO(ldap) or TODO(issue-number). Followed by ":".

[mattsh, 2012/03/27 02:30:25]

Done.

+    // are located
+    if (filename == "dartdir/frog/leg/coreimpl.dart") {
+      filename = "dartdir/frog/leg/lib/coreimpl.dart";
+    }     
+    String text = getText(idOfFilename(filename));
+    print("read $filename (${text.length} bytes)");

[floitsch, 2012/03/26 22:07:05]

debug code?

+    return text;
+  }
+
+  void diagnosticHandler(uri_lib.Uri uri, int begin, int end,
+                                 String message, bool fatal) {
+    warnings += message + "\n";
+  }
+
+  Future<String> readUriFromString(uri_lib.Uri uri) {
+    Completer<String> completer = new Completer<String>();
+    completer.complete(readAll(uri.toString()));
+    return completer.future;
+  }
+
+  /**
+   * Returns the id of the <script> element that contains
+   * the contents of this file.  (Replace all slashes
+   * and dots in the file name with underscores.)
+   */
+  String idOfFilename(String filename) {
+    return filename.replaceAll("/", "_").replaceAll(".", "_");
+  }
+
+  void go() {
+    String mainFile = getText(MAIN_ID);
+    setText("input", readAll(mainFile));
+    int time1 = new Date.now().value;    

[floitsch, 2012/03/26 22:07:05]

use Stopwatch class instead.

+    runLeg();
+    int time2 = new Date.now().value;
+    setText("output", output);
+    setText("warnings", warnings);
+    String timing = "generated ${output.length} characters in " +
+        "${((time2 - time1) / 1000).toStringAsPrecision(3)} seconds";

[floitsch, 2012/03/26 22:07:05]

toStringAsFixed?

+    setText("timing", timing);
+  }
+
+  void runLeg() {
+    uri_lib.Uri mainUri = new uri_lib.Uri.fromString(getText(MAIN_ID));
+    uri_lib.Uri libraryRoot = 
+        new uri_lib.Uri.fromString("dartdir/frog/leg/lib");
+    List<String> compilerArgs = [
+      "--enable_type_checks",
+      "--enable_asserts"
+    ];
+    Future<String> futureJavascript = api_lib.compile(mainUri,
+         libraryRoot, readUriFromString, diagnosticHandler, compilerArgs);    
+    if (futureJavascript == null) {
+      output = "throw 'legpad compilation error';\n";
+      return;
+    } 
+    output = futureJavascript.value;

[floitsch, 2012/03/26 22:07:05]

You can't assume that the future has completed.
Either pass in a closure to runLeg, or return the future and let 'go' register
the 'then' part.

[mattsh, 2012/03/27 02:30:25]

added TODO for compiler to add synchronous API.

+  }
+
+  void setText(String id, String text) {
+    html.Element element = html.document.query("#$id");
+    if (element === null) {
+      throw new Exception("Can't find element $id");
+    }
+    element.innerHTML = htmlEscape(text);
+  }
+
+  String getText(String id) {
+    html.Element element = html.document.query("#$id");
+    if (element === null) {
+      throw new Exception("Can't find element $id");
+    }
+    return element.text.trim();
+  }
+
+  // TODO: should exist in standard lib somewhere

[floitsch, 2012/03/26 22:07:05]

TODO(ldap)

[mattsh, 2012/03/27 02:30:25]

Done.

+  static String htmlEscape(String text) {
+    return text.replaceAll('&', '&').replaceAll(
+        '>', '&gt;').replaceAll('<', '&lt;');
+  }
+}