This is a yet another utilities library. It is used by only a single
poftheday’s dependency - xml-emitter, reviewed on 10 May.
Amount of tools in this toolbox is not very large and mostly covered by more popular libs.
For example, it has a macro for item collection. For example, this macro can be useful to collect hash key value pairs into an alist. But this facility is also available from UIOP:
POFTHEDAY> (let ((the-hash #h(:foo "bar"
:blah "minor")))
(cl-utilities:collecting
(maphash
(lambda (key value)
(cl-utilities:collect
(cons key value)))
the-hash)))
((:FOO . "bar") (:BLAH . "minor"))
;; Here is the similar code using UIOP
POFTHEDAY> (let ((the-hash #h(:foo "bar"
:blah "minor")))
(uiop:while-collecting (collect)
(maphash
(lambda (key value)
(collect (cons key value)))
the-hash)))
((:FOO . "bar") (:BLAH . "minor"))
But UIOP is more powerful allows you to collect many types of items simultaneously. For example, we might want to collect keys and values into the separate lists:
POFTHEDAY> (let ((the-hash #h(:foo "bar"
:blah "minor")))
(uiop:while-collecting (collect-key collect-value)
(maphash
(lambda (key value)
(collect-key key)
(collect-value value))
the-hash)))
(:FOO :BLAH)
("bar" "minor")
An interesting feature is a function read-delimited. It can be useful to
read chars from the stream into a limited buffer:
POFTHEDAY> (with-input-from-string (stream "The string
with multiple
lines.")
(let ((buffer (str:repeat 10 " ")))
(loop for num-chars = (cl-utilities:read-delimited
buffer
stream)
while (not (zerop num-chars))
do (format t "~A chars were read~%"
num-chars)
(format t "Buffer: ~A~2%"
(str:substring 0 num-chars
buffer)))))
10 chars were read
Buffer: The string
10 chars were read
Buffer: with multi
2 chars were read
Buffer: le
6 chars were read
Buffer: lines.
Probably this facility is also covered by more popular utility library?