Curried Definitions ​

The macros in this section are provided by

emacs-lisp
(use-modules (ice-9 curried-definitions))

and replace those provided by default.

Prior to Guile 2.0, Guile provided a type of definition known colloquially as a “curried definition”. The idea is to extend the syntax of define so that you can conveniently define procedures that return procedures, up to any desired depth.

For example,

emacs-lisp
(define ((foo x) y)
  (list x y))

is a convenience form of

emacs-lisp
(define foo
  (lambda (x)
    (lambda (y)
      (list x y))))

Scheme Syntax: define (… (name args …) …) body … ​

Scheme Syntax: define* (… (name args …) …) body … ​

Scheme Syntax: define-public (… (name args …) …) body … ​

Create a top level variable name bound to the procedure with parameter list args. If name is itself a formal parameter list, then a higher order procedure is created using that formal-parameter list, and returning a procedure that has parameter list args. This nesting may occur to arbitrary depth.

define* is similar but the formal parameter lists take additional options as described in lambda* and define*.. For example,

emacs-lisp
(define* ((foo #:keys (bar 'baz) (quux 'zot)) frotz #:rest rest)
  (list bar quux frotz rest))

((foo #:quux 'foo) 1 2 3 4 5)
⇒ (baz foo 1 (2 3 4 5))

define-public is similar to define but it also adds name to the list of exported bindings of the current module.