README.md in hashdiff-0.0.3 vs README.md in hashdiff-0.0.4
- old
+ new
@@ -1,38 +1,49 @@
-HashDiff
-=========
+# HashDiff
+[](http://travis-ci.org/liufengyun/hashdiff)
+
HashDiff is a ruby library to compute the smallest difference between two hashes.
-Requirements
-------------
-HashDiff is tested on following platforms:
+**Demo**: [HashDiff](http://hashdiff.herokuapp.com/)
-- 1.8.7
-- 1.9.2
-- 1.9.3
-- rbx
-- rbx-2.0
-- ree
-- jruby
-- ruby-head
+**Docs**: [Documentation](http://rubydoc.info/gems/hashdiff)
-Usage
-------------
-If you're using bundler, add following:
+## Why HashDiff?
+Given two Hashes A and B, sometimes you face the question: what's the smallest changes that can be made to change A to B?
+
+An algorithm responds to this question has to do following:
+
+* Generate a list of additions, deletions and changes, so that `A + ChangeSet = B` and `B - ChangeSet = A`.
+* Compute recursively -- Arrays and Hashes may be nested arbitrarily in A or B.
+* Compute the smallest change -- it should recoganize similar child Hashes or child Arrays between A and B.
+
+HashDiff answers the question above in an opinionated approach:
+
+* Hash can be represented as a list of (dot-syntax-path, value) pairs. For example, `{a:[{c:2}]}` can be represented as `["a[0].c", 2]`.
+* The change set can be represented using the do-syntax representation. For example, `[['-', 'b.x', 3], ['~', 'b.z', 45, 30], ['+', 'b.y', 3]]`.
+* It compares Arrays using LCS(longest common subsequence) algorithm.
+* It recoganize similar Hashes in Array using a similarity value(0 < similarity <= 1).
+
+
+## Compatibility
+
+HashDiff is tested against `1.9.2`, `1.9.3` and `ruby-head`. It should work on other versions as well.
+
+## Usage
+
+If you're using bundler, add following to the Gemfile:
+
gem 'hashdiff'
Or, you can run `gem install hashdiff`, then add following line to your ruby file which uses HashDiff:
require 'hashdiff'
-Quick Start
------------
+## Quick Start
-You can find full docs here: [Documentation](http://rubydoc.info/gems/hashdiff)
-
### Diff
Two simple hash:
a = {a:3, b:2}
@@ -63,21 +74,20 @@
a = {a: 3}
b = {a: {a1: 1, a2: 2}}
diff = HashDiff.diff(a, b)
- HashDiff.patch(a, diff).should == b
+ HashDiff.patch!(a, diff).should == b
unpatch example:
a = [{a: 1, b: 2, c: 3, d: 4, e: 5}, {x: 5, y: 6, z: 3}, 1]
b = [1, {a: 1, b: 2, c: 3, e: 5}]
diff = HashDiff.diff(a, b) # diff two array is OK
- HashDiff.unpatch(b, diff).should == a
+ HashDiff.unpatch!(b, diff).should == a
-License
--------
+## License
HashDiff is distributed under the MIT-LICENSE.