Start compiling to Fletch bytecodes.

pkg/fletchc/lib/generate_bytecodes.dart

 // Copyright (c) 2015, the Fletch 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.md file.
 
 main() {
   print("""
 // Copyright (c) 2015, the Fletch 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.md file.
 
@@ skipping 24 matching lines @@
         break;
       case "I":
         String field = "uint32Argument$i";
         fields.add(field);
         encode.add("        ..addUint32($field)\n");
         break;
       default:
         throw "Unknown format: $code";
     }
   }
+
+  String toStringExpression = formatString;
+  if (!fields.isEmpty) {
+    List<String> parts = formatString.split("%d");
+    StringBuffer buffer = new StringBuffer();
+    Iterator iterator = fields.iterator;
+    for (String part in parts) {
+      buffer.write(part);
+      if (iterator.moveNext()) {
+        buffer.write(r'${');
+        buffer.write(iterator.current);
+        buffer.write('}');
+      }
+    }
+    toStringExpression = '$buffer';
+  }
+
 print("""
 
 class $name extends Bytecode {
 ${
   fields.map((a) => '  final int $a;\n').join('')
 }  const $name(${fields.map((a) => 'this.$a').join(', ')})
       : super();
 
   Opcode get opcode => Opcode.$name;
 
   String get name => '$name';
 
   String get format => '$format';
 
   int get size => $size;
 
   int get stackPointerDifference => $spDiff;
 
   String get formatString => '$formatString';
 
   void addTo(Sink<List<int>> sink) {
     buffer
         ..addUint8(opcode.index)
 ${
   encode.join("")
 }        ..sendOn(sink);
   }
+
+  String toString() => '$toStringExpression';
 }""");
   });
 }
 
 void doBytecodes(V(String name, String format, int size, spDiff,
                    String formatString)) {
   // Code below was copied from src/shared/bytecodes.h.
   var kVarDiff = "VAR_DIFF";
   /* Name              Format Size   SP-diff  format-string */
   V("LoadLocal0",            "",   1,        1, "load local 0");
@@ skipping 87 matching lines @@
   V("Identical",             "",   1,       -1, "identical");
   V("IdenticalNonNumeric",   "",   1,       -1, "identical non numeric");
 
   V("EnterNoSuchMethod",     "",   1,        3, "enter noSuchMethod");
   V("ExitNoSuchMethod",      "",   1,       -1, "exit noSuchMethod");
 
   V("FrameSize",             "B",  2, kVarDiff, "frame size %d");
 
   V("MethodEnd",             "I",  5,        0, "method end %d");
 }