moba1 / maybe

Crystal maybe monad

maybe

Maybe Monad for Crystal

Installation

1. Add the dependency to your shard.yml:

   dependencies:
     maybe:
       github: moba1/maybe

2. Run shards install

Usage

require "maybe"

j = Maybe::Just.new(1)
p j.to_s # ==> Maybe::Just(Int32)(1)
p j.map { |x| x * 2 } # ==> Maybe::Just(Int32)(2)
p j.or_else(3) # ==> Maybe::Just(Int32)(1)

n = Maybe::Nothig(String).new # require type parameter in order to infer type
p n.to_s # ==> Maybe::Nothing(String)
p n.map { |x| x * 2 } # ==> Maybe::Nothing(Int32)
p n.or_else("Nothing!") # ==> Maybe::Just(String)("Nothing!")

Contributing

1. Fork it (https://github.com/moba1/maybe/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

• Yuma Fukuda - creator and maintainer