Avoid using RegExps in path to work around issue 19090.

pkg/path/lib/src/parsed_path.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 path.parsed_path;
 
 import 'internal_style.dart';
 import 'style.dart';
 
 class ParsedPath {
@@ skipping 34 matching lines @@
 
     // Remove the root prefix, if any.
     var root = style.getRoot(path);
     var isRootRelative = style.getRelativeRoot(path) != null;
     if (root != null) path = path.substring(root.length);
 
     // Split the parts on path separators.
     var parts = [];
     var separators = [];
 
-    var firstSeparator = style.separatorPattern.matchAsPrefix(path);
-    if (firstSeparator != null) {
-      separators.add(firstSeparator[0]);
-      path = path.substring(firstSeparator[0].length);
-    } else {
-      separators.add('');
-    }
+    var firstSeparator = style.separators.firstWhere(path.startsWith,

[Bob Nystrom, 2014/06/02 22:43:05]

I got a noticeable speed bump (1.61s -> 1.37s) by making this functional too.
Change this whole block to something like:

style.splitPath(path, separators, parts);

Then implement that in the POSIX/URL styles like:

  void splitPath(path, separators, parts) {
    var start = 0;

    if (path.isNotEmpty && path.codeUnitAt(0) == 0x2f /* '/' */) {
      separators.add('/');
      start = 1;
    } else {
      separators.add('');
    }

    for (var i = start; i < path.length; i++) {
      if (path.codeUnitAt(i) == 0x2f /* '/' */) {
        parts.add(path.substring(start, i));
        separators.add(separator);
        start = i + 1;
      }
    }

    // Add the final part, if any.
    if (start < path.length) {
      parts.add(path.substring(start));
      separators.add('');
    }
  }

And Windows:


  void splitPath(path, separators, parts) {
    var start = 0;

    if (path.isNotEmpty &&
        (path.codeUnitAt(0) == 0x2f /* '/' */ || path.codeUnitAt(0) == 0x5c /*
'\' */)) {
      separators.add(path[0]);
      start = 1;
    } else {
      separators.add('');
    }

    for (var i = start; i < path.length; i++) {
      if (path.codeUnitAt(i) == 0x2f /* '/' */ || path.codeUnitAt(i) == 0x5c /*
'\' */) {
        parts.add(path.substring(start, i));
        separators.add(path[i]);
        start = i + 1;
      }
    }

    // Add the final part, if any.
    if (start < path.length) {
      parts.add(path.substring(start));
      separators.add('');
    }
  }

This would let you ditch .separators on Style, which gets it closer to a pure
method-based API.

[nweiz, 2014/06/02 23:13:25]

Done, with a little less code duplication.

+        orElse: () => '');
+    separators.add(firstSeparator);
+    path = path.substring(firstSeparator.length);
 
     var start = 0;
-    for (var match in style.separatorPattern.allMatches(path)) {
-      parts.add(path.substring(start, match.start));
-      separators.add(match[0]);
-      start = match.end;
+    for (var i = 0; i < path.length; i++) {
+      for (var separator in style.separators) {
+        if (path[i] == separator) {
+          parts.add(path.substring(start, i));
+          separators.add(separator);
+          start = i + 1;
+        }
+      }
     }
 
     // Add the final part, if any.
     if (start < path.length) {
       parts.add(path.substring(start));
       separators.add('');
     }
 
     return new ParsedPath._(style, root, isRootRelative, parts, separators);
   }
@@ skipping 48 matching lines @@
 
     // If we collapsed down to nothing, do ".".
     if (newParts.length == 0 && !isAbsolute) {
       newParts.add('.');
     }
 
     // Canonicalize separators.
     var newSeparators = new List.generate(
         newParts.length, (_) => style.separator, growable: true);
     newSeparators.insert(0,
-        isAbsolute && newParts.length > 0 &&
-                root.contains(style.needsSeparatorPattern) ?
+        isAbsolute && newParts.length > 0 && style.needsSeparator(root) ?
             style.separator : '');
 
     parts = newParts;
     separators = newSeparators;
 
     // Normalize the Windows root if needed.
     if (root != null && style == Style.windows) {
       root = root.replaceAll('/', '\\');
     }
     removeTrailingSeparators();
@@ skipping 29 matching lines @@
     if (lastDot <= 0) return [file, ''];
 
     return [file.substring(0, lastDot), file.substring(lastDot)];
   }
 
   ParsedPath clone() => new ParsedPath._(
       style, root, isRootRelative,
       new List.from(parts), new List.from(separators));
 }