屍術/Necromancy

*屍術/Necromancy* conjures up the functional code.

.. code

ruby

require 'necromancy'
N = Necromancy.new

# [:foo, :bar, :baz].map{|s| s.to_s }.map{|s| s.upcase }
[:foo, :bar, :baz].map &N.to_s . upcase

# [:foo, :hoge, :bar, :fuga].select{|s| s.to_s.length > 3} # => [:hoge, :fuga]
[:foo, :hoge, :bar, :fuga].select &N.to_s . length > 3

Features

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Function composition ________________

Every messages to instance of Necromancy are function composition by default. that is left-to-right composition.

.. code

ruby

N.f.g == ->(o) { :g.to_proc(:f.to_proc(o)) } == ->(o) { o.f.g }

Application with arguments ________________

If a message was called with some argument given, their arguments are given into that function each time.

.. code

ruby

N.f(x) == ->(o) { :f.to_proc(o, x) } == ->(o) { o.f(x) }

Rich extensions. ________________

If you want, you can use extensions by clojuring up the evil spirit.

.. code

ruby

M = Necromancy.Alternative.new
M.x | M.y == ->(o) { o.x || o.y }

No core extensions. ________________

Open classes is evil unless that is need really! *屍術/Necromancy* isn’t. All methods are defining at local modules, and you can call their methods by sending some messages to a Necromancy object.

Examples

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Simple function composition ________________

First, you create a Necromancy object. it is immutable, you can save it to any variable you like. for example, that is constant, global varibale, instance variable, class variable, local variable, etc.

.. code

ruby

N = Necromancy.new

After, you send some message to N when you need to write a simple block.

.. code

ruby

(1..5).map &N ** 2 # => [1, 4, 9, 16, 25]

Function composition ________________

.. code

ruby

N = Necromancy.Category.new
ary = ('A'..'Z').to_a
(0..4).map &N > ary.method(:[]) # => ["A", "B", "C", "D", "E"]

Multiple accessing to attribtues ________________

.. code

ruby

N = Necromancy.Arrow.new
str = "foo"
lambda(&N.upcase & :capitalize & :reverse).(str) # => ["FOO", "Foo", "oof"]

Maybe evaluating ________________

.. code

ruby

N = Necromancy.Alternative.new
n = N >> N.upcase!
"foo".tap &n # => "FOO"
nil.tap &n # => nil

Alias importation ________________

.. code

ruby

N = Necromancy.Alternative[:>> => :then].new
str_or_nil = ["foo", nil].sample
str_or_nil.tap &(N.then N.upcase!) # => nil or "FOO"

Hiding importation ________________

.. code

ruby

N = Necromancy.Alternative.hiding(:*, :**).new
(1..5).map &N ** 2 # => [1, 4, 9, 16, 25]

Specifying importation ________________

.. code

ruby

N = Necromancy.Alternative(:>>).new
str_or_nil = ["foo", nil].sample
str_or_nil.tap &N >> N.upcase! # => nil or "FOO"
(1..5).map &N ** 2 # => [1, 4, 9, 16, 25]

Multiple module importation ________________

.. code

ruby

N = Necromancy.Arrow.Alternative.hiding(:*, :**).new
[nil, 42, "foo"].map &N.is_a?(Integer) >> (N * 2 & N ** 2) | N # => [nil, [84, 1764], "foo"]

Installation

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.. code

sh

gem install necromancy