https://github.com/alehander92/matchete
A DSL for method overloading in Ruby based on pattern matching
https://github.com/alehander92/matchete
dsl gem pattern-matching ruby
Last synced: about 1 month ago
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A DSL for method overloading in Ruby based on pattern matching
- Host: GitHub
- URL: https://github.com/alehander92/matchete
- Owner: alehander92
- License: mit
- Created: 2014-03-20T16:15:43.000Z (almost 12 years ago)
- Default Branch: master
- Last Pushed: 2015-06-09T12:49:34.000Z (over 10 years ago)
- Last Synced: 2026-01-14T11:15:00.360Z (about 1 month ago)
- Topics: dsl, gem, pattern-matching, ruby
- Language: Ruby
- Homepage:
- Size: 153 KB
- Stars: 55
- Watchers: 3
- Forks: 3
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
Matchete
=========
Matchete provides a DSL for method overloading based on pattern matching for Ruby.
[](https://travis-ci.org/alehander42/matchete)
It's just a quick hack inspired by weissbier and the use-return-values-of-method-definitions DSL technique used in [harmonic](https://github.com/s2gatev/harmonic)
**It supports only ruby 2.1+**
Features
--------
* `on [:value, Integer]` matches an arg with the same internal structure
* `on '#method_name'` matches args responding to `method_name`
* `on AClass` matches instances of `AClass`
* `on a: 2, method:...` matches keyword args
* `on :test?` matches with user-defined predicate methods
* `on either('#count', Array)` matches if any of the tests returns true for an arg
* `on full_match('#count', '#combine')` matches if all of the tests return true for an arg
* `on exact(Integer)` matches special values, used as shortcuts in other cases:
classes, strings starting with '#', etc
* `on having('#count' => 2)` matches objects with properties with certain values
* `default` matches when no match has been found in `on` branches
Install
-----
`gem install matchete`
Usage
-----
```ruby
class Translator
include Matchete
on Any, :string,
def translate(value, to)
value.to_s
end
on '#-@', :negative,
def translate(value, to)
- value
end
on String, :integer,
def translate(value, to)
value.to_i
end
default def translate(value, to)
0
end
end
t = Translator.new
p t.translate 72, :negative # -72
p t.translate nil, :integer # 0
```
```ruby
require 'matchete'
class FactorialStrikesAgain
include Matchete
on 1,
def factorial(value)
1
end
on -> x { x > 1 },
def factorial(value)
value * factorial(value - 1)
end
end
FactorialStrikesAgain.new.factorial(4) #24
FactorialStrikesAgain.new.factorial(-2) #Matchete::NotResolvedError No matching factorial method for args [-2]
```
```ruby
class Converter
include Matchete
on '#special_convert',
def convert(value)
value.special_convert
end
on Integer,
def convert(value)
[:integer, value]
end
on Hash,
def convert(values)
[:dict, values.map { |k, v| [convert(k), convert(v)] }]
end
on /reserved_/,
def convert(value)
[:reserved_symbol, value]
end
on String,
def convert(value)
[:string, value]
end
on ['deleted', [Integer, Any]],
def convert(value)
['deleted', value[1]]
end
on :starts_with_cat?,
def convert(value)
[:fail, value]
end
on free: Integer, method:
def convert(free:)
[:rofl, free]
end
on either('#count', Array),
def convert(value)
value.count
end
on full_match('#count', '#lala'),
def convert(value)
value.count + value.lala
end
default def convert(value)
[:z, value]
end
def starts_with_cat?(value)
value.to_s.start_with?('cat')
end
end
class Z
def special_convert
[:special_convert, nil]
end
end
converter = Converter.new
p Converter.instance_methods
p converter.convert(2) #[:integer, 2]
p converter.convert(Z.new) #[:special_convert, nil]
p converter.convert([4, 4]) # 2
p converter.convert({2 => 4}) #[:dict, [[[:integer, 2], [:integer, 4]]]
p converter.convert('reserved_l') #[:reserved_symbol, 'reserved_l']
p converter.convert('zaza') #[:string, 'zaza']
p converter.convert(['deleted', [2, Array]]) #['deleted', [2, Array]]
p converter.convert(:cat_hehe) #[:fail, :cat_hehe]
p converter.convert(free: 2) #[:rofl, 2]
p converter.convert(2.2) #[:z, 2.2]
```
version
-------
0.5.1
cbb
-----
Todo
-----
* Clean up the specs, right now they're a mess.
* Fix all kinds of edge cases
Copyright
-----
Copyright (c) 2015 Alexander Ivanov. See LICENSE for further details.