From 928af4355700271bd16dc99ab702360fcf25c503 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hugo=20H=C3=B6rnquist?= <hugo@lysator.liu.se>
Date: Mon, 8 Apr 2019 11:56:16 +0200
Subject: Add mulit-set!

---
 module/util.scm | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

(limited to 'module/util.scm')

diff --git a/module/util.scm b/module/util.scm
index 249e2de2..25be0389 100644
--- a/module/util.scm
+++ b/module/util.scm
@@ -6,7 +6,7 @@
                                define-quick-record
                                mod! sort* sort*!
                                find-min)
-  #:replace (let*)
+  #:replace (let* set!)
   )
 
 (define-public upstring->symbol (compose string->symbol string-upcase))
@@ -136,6 +136,21 @@
 
 
 
+;; Allow set to work on multiple values at once,
+;; similar to Common Lisp's @var{setf}
+;; @example
+;; (set! x 10
+;;       y 20)
+;; @end example
+;; Still requires all variables to be defined beforehand.
+(define-syntax set!
+  (syntax-rules ()
+    ((_ field val)
+     ((@ (guile) set!) field val))
+    ((_ field val rest ...)
+     (begin ((@ (guile) set!) field val)
+            (set! rest ...)))))
+
 ;; Like set!, but applies a transformer on the already present value.
 (define-syntax-rule (mod! field transform-proc)
   (set! field (transform-proc field)))
-- 
cgit v1.2.3