|tagger||Natalie Weizenbaum <email@example.com>||Tue Nov 17 16:08:42 2015 -0800|
Performance improvements for absolute() and normalize().
|author||Natalie Weizenbaum <firstname.lastname@example.org>||Tue Nov 17 16:03:56 2015 -0800|
|committer||Natalie Weizenbaum <email@example.com>||Tue Nov 17 16:03:56 2015 -0800|
Optimize absolute() and normalize(). This short-circuits absolute() if the path is already absolute. Detecting absolute paths is very fast, whereas join() is relatively slow. For normalize(), this runs a single-pass check over a path to see whether it needs to be normalized at all. This check isn't free, but it's a lot less costly than parsing and reserializing the path, and it covers the common case. See dart-lang/glob#24962 Rfirstname.lastname@example.org Review URL: https://codereview.chromium.org//1455003002 .
A comprehensive, cross-platform path manipulation library for Dart.
The path package provides common operations for manipulating paths: joining, splitting, normalizing, etc.
We‘ve tried very hard to make this library do the “right” thing on whatever platform you run it on, including in the browser. When you use the top-level functions, it will assume the current platform’s path style and work with that. If you want to explicitly work with paths of a specific style, you can construct a
path.Context for that style.
The path library was designed to be imported with a prefix, though you don‘t have to if you don’t want to:
import 'package:path/path.dart' as path;
The most common way to use the library is through the top-level functions. These manipulate path strings based on your current working directory and the path style (POSIX, Windows, or URLs) of the host platform. For example:
This calls the top-level [join] function to join “directory” and “file.txt” using the current platform's directory separator.
If you want to work with paths for a specific platform regardless of the underlying platform that the program is running on, you can create a [Context] and give it an explicit [Style]:
var context = new path.Context(style: Style.windows); context.join("directory", "file.txt");
This will join “directory” and “file.txt” using the Windows path separator, even when the program is run on a POSIX machine.
Pathos runs on the Dart VM and in the browser under both dart2js and Dartium. Under dart2js, it currently returns “.” as the current working directory, while under Dartium it returns the current URL.
When you have path objects, then every API that takes a path has to decide if it accepts strings, path objects, or both.
Accepting strings is the most convenient, but then it seems weird to have these path objects that aren‘t actually accepted by anything that needs a path. Once you’ve created a path, you have to always call
.toString() on it before you can do anything useful with it.
Requiring objects forces users to wrap path strings in these objects, which is tedious. It also means coupling that API to whatever library defines this path class. If there are multiple “path” libraries that each define their own path types, then any library that works with paths has to pick which one it uses.
Taking both means you can‘t type your API. That defeats the purpose of having a path type: why have a type if your APIs can’t annotate that they expect it?
Given that, we've decided this library should simply treat paths as strings.
We believe this library handles most of the corner cases of Windows paths (POSIX paths are generally pretty straightforward):
It understands that both “/” and "" are valid path separators, not just "".
It can accurately tell if a path is absolute based on drive-letters or UNC prefix.
It understands that “/foo” is not an absolute path on Windows.
It knows that “C:\foo\one.txt” and “c:/foo\two.txt” are two files in the same directory.
If you use this package in a browser, then it considers the “platform” to be the browser itself and uses URL strings to represent “browser paths”.