Add a "terse" argument to foldFrames().

lib/src/trace.dart

 // Copyright (c) 2013, 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 trace;
 
 import 'dart:collection';
 import 'dart:math' as math;
 
 import 'chain.dart';
@@ skipping 185 matching lines @@
   /// representation in the Dart VM's stack trace format, regardless of what
   /// platform is being used.
   StackTrace get vmTrace => new VMTrace(frames);
 
   /// Returns a terser version of [this].
   ///
   /// This is accomplished by folding together multiple stack frames from the
   /// core library or from this package, as in [foldFrames]. Remaining core
   /// library frames have their libraries, "-patch" suffixes, and line numbers
   /// removed.
-  Trace get terse {
-    return new Trace(foldFrames((frame) {
-      if (frame.isCore) return true;
-      if (frame.package == 'stack_trace') return true;
-
-      // Ignore async stack frames without any line or column information. These
-      // come from the VM's async/await implementation and represent internal
-      // frames. They only ever show up in stack chains and are always
-      // surrounded by other traces that are actually useful, so we can just get
-      // rid of them.
-      // TODO(nweiz): Get rid of this logic some time after issue 22009 is
-      // fixed.
-      if (!frame.member.contains('<async>')) return false;
-      return frame.line == null;
-    }).frames.map((frame) {
-      if (!frame.isCore) return frame;
-      var library = frame.library.replaceAll(_terseRegExp, '');
-      return new Frame(Uri.parse(library), null, null, frame.member);
-    }));
-  }
+  ///
+  /// For custom folding, see [foldFrames].
+  Trace get terse => foldFrames((_) => false, terse: true);
 
   /// Returns a new [Trace] based on [this] where multiple stack frames matching
-  /// [predicate] are folded together. This means that whenever there are
-  /// multiple frames in a row that match [predicate], only the last one is
-  /// kept.
+  /// [predicate] are folded together.
   ///
-  /// This is useful for limiting the amount of library code that appears in a
-  /// stack trace by only showing user code and code that's called by user code.
-  Trace foldFrames(bool predicate(Frame frame)) {
-    var newFrames = <Frame>[];
+  /// This means that whenever there are multiple frames in a row that match
+  /// [predicate], only the last one is kept. This is useful for limiting the
+  /// amount of library code that appears in a stack trace by only showing user
+  /// code and code that's called by user code.
+  ///
+  /// If [terse] is true, this will also fold together frames from the core
+  /// library or from this package, and simplify core library frames as in
+  /// [Trace.terse].
+  Trace foldFrames(bool predicate(Frame frame), {bool terse: false}) {
+    if (terse) {
+      var oldPredicate = predicate;
+      predicate = (frame) {
+        if (oldPredicate(frame)) return true;
+
+        if (frame.isCore) return true;
+        if (frame.package == 'stack_trace') return true;
+
+        // Ignore async stack frames without any line or column information. These

[Bob Nystrom, 2015/02/13 16:07:19]

Long lines.

[nweiz, 2015/02/17 21:42:34]

Done.

+        // come from the VM's async/await implementation and represent internal
+        // frames. They only ever show up in stack chains and are always
+        // surrounded by other traces that are actually useful, so we can just get
+        // rid of them.
+        // TODO(nweiz): Get rid of this logic some time after issue 22009 is
+        // fixed.
+        if (!frame.member.contains('<async>')) return false;
+        return frame.line == null;
+      };
+    }
+
+    var newFrames = [];
     for (var frame in frames.reversed) {
       if (!predicate(frame)) {
         newFrames.add(frame);
       } else if (newFrames.isEmpty || !predicate(newFrames.last)) {
         newFrames.add(new Frame(
             frame.uri, frame.line, frame.column, frame.member));
       }
     }
 
+    if (terse) {
+      newFrames = newFrames.map((frame) {
+        if (!frame.isCore) return frame;
+        var library = frame.library.replaceAll(_terseRegExp, '');
+        return new Frame(Uri.parse(library), null, null, frame.member);
+      }).toList();
+    }
+
     return new Trace(newFrames.reversed);
   }
 
   /// Returns a human-readable string representation of [this].
   String toString() {
     // Figure out the longest path so we know how much to pad.
     var longest = frames.map((frame) => frame.location.length)
         .fold(0, math.max);
 
     // Print out the stack trace nicely formatted.
     return frames.map((frame) {
       return '${padRight(frame.location, longest)}  ${frame.member}\n';
     }).join();
   }
 }