initial frogpad

frog/pad/frogpad.dart

+// 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.
+
+/**
+ * This is the entrypoint for a version of the frog compiler that 
+ * can run in the browser.
+ * Because this is running in the browser, frog cannot access
+ * the file system.  Instead, we assume the all necessary files
+ * have been placed in inert <script> elements somewhere on the page.  
+ * (See frogpad.py for more details on how the html page is constructed.)
+ */
+
+#import("dart:html", prefix:"html");
+#import("../lang.dart");
+#import("../file_system.dart");
+
+// id of script element containing name of the main dart file
+// to compile.
+final String MAIN_ID = "main_id";
+
+void main() {
+  String warnings = "";
+  HtmlFileSystem fs = new HtmlFileSystem();
+  String mainFile = getText(MAIN_ID); 
+  setText("input", fs.readAll(mainFile));
+
+  int time1 = new Date.now().value;
+  List<String> args = ["dummy_arg1", "dummy_arg2", mainFile];
+  parseOptions("dummy_home_dir", args, fs);
+
+  options.useColors = false;
+
+  initializeWorld(fs);
+  world.messageHandler = void _(
+      String prefix, String message, SourceSpan span) {
+    String location = "";
+    if (span !== null) {
+      location = span.locationText;
+    }
+    warnings += prefix + message + location + "\n";
+  };
+  bool success = world.compile();
+  int time2 = new Date.now().value;
+  String output = world.getGeneratedCode();
+  if (success) {
+    setText("output", output);
+  }
+  setText("warnings", warnings);
+
+  ((time2 - time1) / 1000).toStringAsPrecision(3);
+  String timing = "generated ${output.length} characters in " + 
+      "${((time2 - time1) / 1000).toStringAsPrecision(3)} seconds";
+  setText("timing", timing);
+}
+
+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(rnystrom): should exist in standard lib somewhere
+String htmlEscape(String text) {
+  return text.replaceAll('&', '&amp;').replaceAll(
+      '>', '&gt;').replaceAll('<', '&lt;');
+}
+
+class HtmlFileSystem implements FileSystem {
+
+  HtmlFileSystem() {}
+
+  String readAll(String filename) {
+    String text = getText(idOfFilename(filename));
+    print("read $filename (${text.length} bytes)");
+    return text;
+  }
+
+  String idOfFilename(String filename) {

[Emily Fortuna, 2012/02/14 19:56:53]

Why'd the comments for this function go away? I thought they were helpful..

[mattsh, 2012/02/14 22:13:40]

Good catch.  I'm not sure how it got deleted, but restored the comment now.

+    List<String> components = filename.split("/");
+    if (components.isEmpty()) {
+      throw new Exception("bad filename");
+    }
+    // Grab the last two components (the directory name and file name).
+    int startIndex = Math.max(0, components.length - 2);
+    int length = components.length - startIndex;;
+    components = components.getRange(startIndex, length);
+    
+    // Join components with underscore, and replace dots with underscore.
+    return Strings.join(components, "_").replaceAll(".", "_");    
+  }
+
+  void writeString(String outfile, String text) {
+    throw new UnsupportedOperationException("");
+  }
+
+  bool fileExists(String filename) {
+    // frog calls this to check if files exist before reading them.  We return 
+    // true here for all files, and let it fail later if frog attempts to read 
+    // the contents of a non-existant file.
+    return true;
+  }
+
+  void createDirectory(String path, [bool recursive]) {
+    throw new UnsupportedOperationException("");
+  }
+  
+  void removeDirectory(String path, [bool recursive]) {
+    throw new UnsupportedOperationException("");
+  }
+}