Ruby: type checkers arguments, akin to Cadence SKILL

Question

In the Cadence SKILL (proprietary EDA language, based on LISP & SCHEME), one can define the argument types in a procedure.
It will error out if the wrong type of argument is given. See shell report below:

procedure( foo( ko "t" ) printf( "Hey %s\n" ko ) )
>foo
>foo("1")
>Hey 1
>t
foo(1)
>*Error* foo: argument #1 should be a string (type template = "t") - 1

Is there something as nifty as that in Ruby? That is, in the method interface definition, not the body, the type checking is done?
Thanks.

No. Ruby does not have built-in type annotations. – Jordan Running Jun 10 '16 at 12:53 — Jordan Running, Jun 10 '16 at 12:53

score 1 · Accepted Answer · answered Jun 10 '16 at 12:42

1

You can make it "nifty" like this:

module FirstArgumentIsAString
  module Initializer
    def initialize(word)
      fail 'Word must be String' unless word.is_a?(String)
      super
    end
  end

  def self.included(klass)
    klass.send :prepend, Initializer
  end
end

class Foo
  include FirstArgumentIsAString
end

y = Foo.new(2)
> Uncaught exception: Word must be String

answered Jun 10 '16 at 12:42

Mike S

324
1
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Wow. Almost what I wanted, I can tweak this to make it what I have envisioned. Thanks. – user1134991 Jun 13 '16 at 16:00

Mike S · Answer 2 · 2016-06-10T12:40:32.523

0

You can always do

fail 'Keep input as a string' unless variable_name.is_a?(String)

while it is not dynamic typing language way of thinking, try to achieve duck-typing

edited Jun 10 '16 at 12:40

answered Jun 10 '16 at 10:56

Mike S

324
1
10

Ruby: type checkers arguments, akin to Cadence SKILL

2 Answers2