guile-borrow

guile-borrow is a Guile library that borrows syntax and features from other Lisps, namely Racket and Clojure. The main purpose of this collection is to make Guile more familiar to other lisp programmers.

guile-borrow is primarily a collection of features which are typically implemented using Macros but since not all syntactic constructs can be built as macros, more complicated borrowed features will be implemented in forms of Guile extensions.

Examples

;; A clojure-like let
(define-syntax let1
  (syntax-rules ()
    ((_ (var val) exp exp* ...)
     (let ((var val)) exp exp* ...))))

;; If test is true, evaluates then with binding-form bound to the
;; value of test, if not, yields else
(define-syntax if-let
  (syntax-rules ()
    ((_ (binding value) then else)
     (let1 (binding value)
           (if binding then else)))))

;; When test is true evaluates body with binding-form bound to the
;; value of test
(define-syntax when-let
  (syntax-rules ()
    ((_ (binding value) body ...)
     (let1 (binding value)
           (when binding body ...)))))

;; a short-hand to (if (not something) ...)
(define-syntax if-not
  (syntax-rules ()
    ((_ test then else)
     (if (not test) then else))))

;; Like when but reversed
(define-syntax when-not
  (syntax-rules ()
    ((_ test body ...)
     (when (not test) body ...))))