Added support for dumping AST to console, text file or dot file

compiler/java/com/google/dart/compiler/DartCompiler.java

Index: compiler/java/com/google/dart/compiler/DartCompiler.java
===================================================================
--- compiler/java/com/google/dart/compiler/DartCompiler.java	(revision 1522)
+++ compiler/java/com/google/dart/compiler/DartCompiler.java	(working copy)
@@ -18,6 +18,10 @@
 import com.google.dart.compiler.ast.LibraryNode;
 import com.google.dart.compiler.ast.LibraryUnit;
 import com.google.dart.compiler.ast.Modifiers;
+import com.google.dart.compiler.ast.viz.BaseASTWriter;
+import com.google.dart.compiler.ast.viz.ConsoleWriter;
+import com.google.dart.compiler.ast.viz.DotWriter;
+import com.google.dart.compiler.ast.viz.TextWriter;
 import com.google.dart.compiler.common.SourceInfo;
 import com.google.dart.compiler.metrics.CompilerMetrics;
 import com.google.dart.compiler.metrics.DartEventType;
@@ -664,6 +668,19 @@
       try {
         // Set entry point
         setEntryPoint();
+        
+        //Dump the compiler parse tree if dump format is set in arguments
+        String astFormat = config.getCompilerOptions().dumpAST();
+        String outDir = config.getCompilerOptions()
+                  .getWorkDirectory().getAbsolutePath();
+        BaseASTWriter astWriter = null;

[zundel, 2011/11/15 14:49:54]

One way you could do this without intruding into the calling code when you add
new writers is to use the Factory pattern.  You would create a static method
like:

 BaseASTWriter AstWriterFactory.create(String type)

Then you could move the if ladder into the factory.  The advantage to this is
that you don't have to disturb callers of the factory when you change the types
of writers supported.

[shauvik, 2011/11/15 23:53:14]

I moved most of the code in the factory. i.e. passed the config to the factory
as it needs to access outDir as well.
Looks much cleaner now.

On 2011/11/15 14:49:54, zundel wrote:

+        if("console".equals(astFormat)) {

[zundel, 2011/11/15 14:49:54]

add space between if and ( 
(here and elsewhere)

[shauvik, 2011/11/15 23:53:14]

Ctrl+Shift+F fixed it. Thanks.

On 2011/11/15 14:49:54, zundel wrote:

+          astWriter = new ConsoleWriter(outDir);
+        }else if("text".equals(astFormat)) {

[zundel, 2011/11/15 14:49:54]

add space between } and else  (here and elsewhere)

[shauvik, 2011/11/15 23:53:14]

Fixed. Thanks.
On 2011/11/15 14:49:54, zundel wrote:

+          astWriter = new TextWriter(outDir);
+        }else if("dot".equals(astFormat)) {
+          astWriter = new DotWriter(outDir);
+        }
 
         // The two following for loops can be parallelized.
         for (LibraryUnit lib : libraries.values()) {
@@ -671,6 +688,9 @@
 
           // Compile all the units in this library.
           for (DartUnit unit : lib.getUnits()) {
+          
+            if(astWriter != null) astWriter.process(unit);

[zundel, 2011/11/15 14:49:54]

style: in Java, we always surround the if block with { }

[shauvik, 2011/11/15 23:53:14]

Okay, Done!

On 2011/11/15 14:49:54, zundel wrote:

+            
             // Don't compile api-only units.
             if (unit.isDiet()) {
               continue;