[GROOVY-4998] Real currying support

• Type: New Feature
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Fix Version/s: 4.x
• Component/s: groovy-jdk
• Assignee: Unassigned
• Reporter: Kentaro Yoshida
• Created: 05/Sep/11 16:31
• Updated: 27/Jan/20 09:54

Description

Hi.

Groovy's Closure have a name of method 'curry'.
But this is not work for a real currying, it work as a partial function application.
So, I wrote method of 'Real currying'.

Referenced http://en.wikipedia.org/wiki/Currying

Closure add = {a, b, c -> a + b + c } // Closure of adding 3 arguments.

assert add(1, 2, 3) == realCurry(add)(1)(2)(3)
assert 6 == add(1, 2, 3)
def curriedAdd = realCurry(add)
def curriedAdd_1 = curriedAdd(1)
def curriedAdd_1_2 = curriedAdd_1(2)
def addResult = curriedAdd_1_2(3)
assert 6 == addResult

def realCurry(Closure clos) {
  if (clos.maximumNumberOfParameters >= 1) {
    return { x ->
      def cc = clos.curry(x)
      if (cc.maximumNumberOfParameters) realCurry(cc)
      else cc()
    }
  } else {
    return clos
  }
}

(It's also published on gist https://gist.github.com/1193548)

I hope this will be adopted to Groovy core.

Thank you.

Issue Links

• is duplicated by: GROOVY-6281 Add Support for curried functions - make Groovy more functional