RubyConf Kwurry Lightning Talk

kwurry_talk.rb

# currying

add = ->(a, b) {
  a + b
}
add_two = add.curry.(2)
# => #<Proc:0x00007f911d0962c0 (lambda)>
add_two.(1)
# => 3



foo = ->(a, b, c=0, *xs) {
  [a, b, c] + xs
}

foo.parameters
# => [[:req, :a], [:req, :b], [:opt, :c], [:rest, :xs]]

foo.curry.parameters
# => [[:rest]]

bar = ->(a:, b:, c: 0, **xs) {
  [a, b, c] + xs.values
}

bar.parameters
# => [[:keyreq, :a], [:keyreq, :b], [:key, :c], [:keyrest, :xs]]

bar.curry.parameters
# => [[:rest]]



foo.curry.(1)
# => #<Proc:0x00007fc5960c7890 (lambda)>
foo.curry.(1).(2)
# => [1, 2, 0]
foo.curry.(1).(2,3)
# => [1, 2, 3]


bar.curry.(a: 1)
# ArgumentError (missing keyword: b)
bar.curry.(a: 1, b: 2)
# => [1, 2, 0]
bar.curry.(a: 1, b: 2, x: 11, y: 12)
# => [1, 2, 0, 11, 12]



require 'kwurry'
require 'kwurry/proc'

bar.kwurry.(b: 2).(a: 1)
# => [1, 2, 0]



greet = ->(greeting, name) {
  "#{greeting}, #{name}"
}
greet.("Hello", "World")
# => "Hello, World"

greet_with_hey = greet.curry.("Hey")
greet_with_hey.("World")
# => "Hey, World"



greet = ->(greeting:, name:) {
  "#{greeting}, #{name}"
}

greet_rubyconf = greet.kwurry.(name: "RubyConf")
greet_rubyconf.(greeting: "Well hello there")
# => "Well hello there, RubyConf"






numberize = ->(a, b, operator:) {
  ([a, b]).reduce(operator)
}
numberize.(3, 5, operator: :+)
# => 8

multiply = numberize.kwurry.(operator: :*)
# ArgumentError (wrong number of arguments (given 1, expected 2; required keyword: operator))