ranger

Range object operation in Crystal

Programming language: Crystal

License: MIT License

Tags: Algorithms And Data Structures    

README

ranger

ranger is a Crystal library to operate on Range objects in Crystal programming language. Current version can include, exclude and two types of split Range object.

First split you choose how many smaller ranges would you like, the second type allow you to specify range length. It is very useful for Time related operations.

Installation

Add this to your application's shard.yml:

dependencies:
  ranger:
    github: akwiatkowski/ranger

Usage

Include simple ranges

require "ranger"

result = (1..2) + (2..3)
puts result.inspect
# [1..3]

Keep in mind that you can only include two Range objects. This is because result is Array(Range). If you include two exclusive Range the result are two Range objects. That means result of inclusion cannot be one Range.

Include more than 2 ranges

In case you want to include more objects please use example below.

require "ranger"

r = Ranger.new(1..2)
r.include(2..3)
r.include(3..4)

result = r.render
puts result.inspect
# [1..4]

Exclude ranges

Exclusion is opposite operation to inclusion. This library allow you to do it.

require "ranger"

result = (1..10) - (5..6)
puts result.inspect
# [1..5, 6..10]

Exclude more ranges

require "ranger"

r = Ranger.new(10..20)
r.exclude(15..16)
r.exclude(18..19)

result = r.render
puts result.inspect
# [10..15, 16..18, 19..20]

Divide/split Range into more objects

You can use ranger to split one Range object into more smaller objects.

result = (0..10) / 2
puts result.inspect
# [0..5, 5..10]

Divide/split Range into specific ranges

If you have 1 month Time Range and would like to divide into 1-week Range objects you can use modulo operator - %.

ra = (Time.new(2016, 1, 1))..(Time.new(2016, 2, 1))
j = Time.new(2016, 1, 8) - Time.new(2016, 1, 1)
result = ra % j

Keep in mind last Range object will be not full 1-week range. If you would like only full 1-week ranges you could change operator to bitwise xor - ^. Sorry, there is lack of proper operators.

ra = (Time.new(2016, 1, 1))..(Time.new(2016, 2, 1))
j = Time.new(2016, 1, 8) - Time.new(2016, 1, 1)
result = ra ^ j

Alternatively there is method div.

ra = (Time.new(2016, 1, 1))..(Time.new(2016, 2, 1))
j = Time.new(2016, 1, 8) - Time.new(2016, 1, 1)
result = ra.div(j, allow_partial: false)

Development

TODO: Write development instructions here

Contributing

1. Fork it ( https://github.com/akwiatkowski/ranger/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• akwiatkowski Aleksander Kwiatkowski - creator, maintainer