Check for compile-time constants in DartCompiler

client/samples/sunflower/Sunflower.dart

 // Copyright (c) 2011, 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.
 
 #library('sunflower');
 
 #import('dart:dom');
 
 #resource('sunflower.css');
 
 main() {
   new Sunflower();
 }
 
 class Sunflower {
   
   Sunflower() {
+    PHI = (Math.sqrt(5) + 1) / 2;
     var doc = window.document;
     
     HTMLCanvasElement canvas = doc.getElementById("canvas");
     xc = yc = MAX_D / 2;
     ctx = canvas.getContext("2d");
     
     HTMLInputElement slider = doc.getElementById("slider");
     slider.onchange = (Event e) {
       seeds = Math.parseInt(slider.value);
       drawFrame();
     };
     
     drawFrame();
   }
   
   // Draw the complete figure for the current number of seeds.
   void drawFrame() {
     ctx.clearRect(0, 0, MAX_D, MAX_D);
     for (var i=0; i<seeds; i++) {
-      var theta = i * PI2 / PHI;
+      var theta = i * TAU / PHI;
       var r = Math.sqrt(i) * SCALE_FACTOR;
       var x = xc + r * Math.cos(theta);
       var y = yc - r * Math.sin(theta);
       drawSeed(x,y);
     }
   }
   
   // Draw a small circle representing a seed centered at (x,y).
   void drawSeed(num x, num y) {
     ctx.beginPath();
     ctx.setLineWidth(2);
     ctx.setFillColor(ORANGE);
     ctx.setStrokeColor(ORANGE);
-    ctx.arc(x, y, SEED_RADIUS, 0, PI2, false);
+    ctx.arc(x, y, SEED_RADIUS, 0, TAU, false);
     ctx.fill();
     ctx.closePath();
     ctx.stroke();
   }
 
   CanvasRenderingContext2D ctx;
   num xc, yc;
   num seeds = 0;
 
   static final SEED_RADIUS = 2;
   static final SCALE_FACTOR = 4;
-  static final PI2 = Math.PI * 2;
-  static final PHI = (Math.sqrt(5)+1) / 2;
+  static final TAU = Math.PI * 2;
+  var PHI;
   static final MAX_D = 300;
   static final String ORANGE = "orange";
 
 }