futils – Function Utilities Library

This library defines forms that abstract some common operations on functions, including counting arguments, creating wrappers, passing proper number of arguments and transforming positional-based arities into named ones.

Installation

The current release is 1.2.3. To use futils in your project, add the following to the dependencies section of project.clj:

[io.randomseed/futils "1.2.3"]

Components

Currently prvided macros and functions are:

• argc – counts arguments a function takes (for all arities),
• apply – works like clojure.core/apply but for named arguments,
• comp – works like clojure.core/comp but for named arguments,
• frepeat – creates a sequence of returned values using a function with named parameters,
• identity – works like clojure.core/identity but for named arguments,
• nameize – transforms a function so it accepts named arguments,
• nameize* – like nameize but requires symbols to be quoted,
• relax – wraps a function in a way that it accepts any number of arguments,
• relax* – like relax but it requires to explicitly describe the accepted arities.

Documentation

Full documentation with usage examples is available on:

• https://randomseed.io/software/futils/

Sneak peeks

(require 'futils.args)
(require 'futils.named)

;; counting arities
;;
(futils.args/argc reduce)
; => {:arities (2 3)
      :engine :jvm
      :variadic false}

;; relaxing arities
;;
(def f (futils.args/relax reduce))
(f + 0 [1 2 3 4] :ignored :args)
; => 10

(def f (futils.args/relax #(vector %1 %2)))
(f 1)
; => [1 nil]

(def f (futils.args/relax #(vector %1 %2) :verbose true))
(f 1)
; => {:argc-cutted 0
; =>  :argc-padded 1
; =>  :argc-received 1
; =>  :argc-sent 2
; =>  :args-received (1)
; =>  :args-sent (1 nil)
; =>  :arities (2)
; =>  :arity-matched 2
; =>  :engine :jvm
; =>  :result [1 nil]
; =>  :variadic false
; =>  :variadic-used false
; =>  :verbose true}

;; nameization
;;
(def f (futils.named/nameize
        reduce
        [f coll]
        [f val coll]))

(f :f +
   :coll [1 1 2 3])
; => 7

(f :f +
   :val 1
   :coll [1 1 2 3])
; => 8

;; function composition
;;
(defn f1 [& {:as args}] (assoc args :f1 1))
(defn f2 [& {:as args}] (assoc args :f2 2))
(def f (futils.named/comp f1 f2))

(f :a 1 :b 2)
; => {:a 1 :b 2 :f1 1 :f2 2}

Examples

Examples can be found in the documentation or in test files located under test/futils subdirectory of the sources.

License

Copyright © 2015-2020 Paweł Wilk

Futils is copyrighted software owned by Paweł Wilk (pw@gnu.org). You may redistribute and/or modify this software as long as you comply with the terms of the GNU Lesser General Public License (version 3).

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.