aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorArun Isaac2021-04-12 00:28:50 +0530
committerArun Isaac2021-04-12 00:31:47 +0530
commit88f6ff9e7268475a5c6fb2222575ca1471e47b3a (patch)
treeea36dbb8bd80f815ed6d5682fa1e7a94c6d8625b
parent3fe79b059de7000ba2e48156fd165fe532048acb (diff)
downloadccwl-88f6ff9e7268475a5c6fb2222575ca1471e47b3a.tar.gz
ccwl-88f6ff9e7268475a5c6fb2222575ca1471e47b3a.tar.lz
ccwl-88f6ff9e7268475a5c6fb2222575ca1471e47b3a.zip
Support n-ary keyword arguments.
* ccwl/utils.scm: New file.
-rw-r--r--ccwl/utils.scm41
1 files changed, 41 insertions, 0 deletions
diff --git a/ccwl/utils.scm b/ccwl/utils.scm
new file mode 100644
index 0000000..90d6f0c
--- /dev/null
+++ b/ccwl/utils.scm
@@ -0,0 +1,41 @@
+(define-module (ccwl utils)
+ #:use-module (srfi srfi-1)
+ #:use-module (srfi srfi-71)
+ #:use-module (ice-9 match)
+ #:export (group-arguments))
+
+(define (group-keyword-arguments args unary-keywords)
+ "Group ARGS, a list of keyword arguments of arbitrary arity. Return
+a list of unary keyword arguments. n-ary arguments are grouped
+together into lists. Keywords that are to be treated as having unit
+arity are listed in UNARY-KEYWORDS."
+ (match args
+ (((? (lambda (keyword)
+ (and (keyword? keyword)
+ (not (member keyword unary-keywords))))
+ this-keyword)
+ tail ...)
+ (let ((this-keyword-args tail (break keyword? tail)))
+ (cons* this-keyword
+ (apply list this-keyword-args)
+ (group-keyword-arguments tail unary-keywords))))
+ (((? (lambda (keyword)
+ (and (keyword? keyword)
+ (member keyword unary-keywords)))
+ this-keyword)
+ this-keyword-arg tail ...)
+ (cons* this-keyword this-keyword-arg
+ (group-keyword-arguments tail unary-keywords)))
+ ((non-keyword _ ...)
+ (error "Invalid sequence of keywords arguments" args))
+ (() '())))
+
+(define* (group-arguments args #:optional (unary-keywords '()))
+ "Group ARGS, a list of positional arguments followed by keyword
+arguments of arbitrary arity. Return a list of positional arguments
+followed by unary keyword arguments. n-ary arguments are grouped
+together into lists. Keywords that are to be treated as having unit
+arity are listed in UNARY-KEYWORDS."
+ (let ((positional-arguments keyword-arguments (break keyword? args)))
+ (append positional-arguments
+ (group-keyword-arguments keyword-arguments unary-keywords))))