Currying

Documentation and user's manual

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OCaml programs

Currying

Currying is the technique of transforming a function that takes multiple arguments into a function that takes a single argument (the first of the arguments to the original function) and returns a new function that takes the remainder of the arguments and returns the result.

Uncurrying is the reverse transformation.

This a definition of the function (named  curry ) that computes the curried version of a function with two arguments: let curry = function f -> (function x -> (function y -> f (x, y)))

Here are applications of  curry  that return functional values previously written: (** The same function as unary_of_int_add. *) (* *) curry (function x, y -> x + y) ;; (*****) (** The same function as unary_of_real_mult. *) (* *) curry (function x, y -> x *. y) ;; (*****) (** The same function as unary_of_string_concat. *) (* *) curry (function x, y -> x ^ y) ;;

This a definition of the function (named  uncurry ) that uncurries the curried version of a function with two arguments: let uncurry = function f -> (function (x, y) -> (f (x)) (y))

Almost all the functions provided by the modules in the libraries of the Objective Caml system only take a single argument. Multiple-arguments functions can be considered as syntactic sugar for nested one-argument functions.

Here are applications of  curry  that computes addition of two integers, multiplication of two real numbers and concatenation of two strings: uncurry (unary_of_int_add) ;; uncurry (unary_of_real_mult) ;; uncurry (unary_of_string_concat) ;;

Currying

Documentation and user's manual

Table of contents

OCaml programs