Using Tuples in Ruby?
Arrays are cool to use as tuples because of destructuring
a = [[1,2], [2,3], [3,4]]
a.map {|a,b| a+b }
Struct give you convenient .
accessors
Person = Struct.new(:first_name, :last_name)
ppl = Person.new('John', 'Connor')
ppl.first_name
ppl.last_name
You can get the convenience of both worlds with to_ary
Person = Struct.new(:first_name, :last_name) do
def to_ary
[first_name, last_name]
end
end
# =>
[
Person.new('John', 'Connor'),
Person.new('John', 'Conway')
].map { |a, b| a + ' ' + b }
# => ["John Connor", "John Conway"]
While this isn't strictly a tuple (can't do dot notation of members), you can assign a list of variables from a list, which often will solve issues with ruby being pass-by-value when you are after a list of return values.
E.g.
:linenum > (a,b,c) = [1,2,3]
:linenum > a
=> 1
:linenum > b
=> 2
:linenum > c
=> 3
Based on the fact that you talk about hashes and . notation I'm going to assume you mean a different kind of tuple than the (1. "a")
sort. You're probably looking for the Struct
class. eg:
Person = Struct.new(:name, :age)
me = Person.new
me.name = "Guy"
me.age = 30
OpenStruct?
Brief example:
require 'ostruct'
person = OpenStruct.new
person.name = "John Smith"
person.age = 70
person.pension = 300
puts person.name # -> "John Smith"
puts person.age # -> 70
puts person.address # -> nil