kezban

Utility library for Clojure and ClojureScript.

The library targets Clojure 1.8 and above.

Leiningen

Usage

kezban.core

;;use kezban.core
(use 'kezban.core)

when-let*

user=> (when-let* [a 1 b 2 c 3]
                  (println "I <3 Clojure")
                  a)
=> "I <3 Clojure"
=> 1

;;returns nil when one binding is nil or false
user=> (when-let* [a 1 b nil c 3]
                  (println "Please print me!")
                  a)
=> nil                              

if-let*

user=> (if-let* [a 1 b 2 c (+ a b)]
                c)
=> 3

;;returns then part when one binding is nil or false
user=> (if-let* [a 1 b nil c 3]
                "Nope not here"
                "Here I Am!")
=> "Here I Am!"         

cond-as->

(cond-as-> 1 n
           true (+ n 1)
           false (+ n 2)
           true  (+  5 n))
=> 7

->>>

;; Alternative to ->, ->> and (comp) with one arg
;; Applying Left-To-Right
;; First Argument has to be a value(input)!

;; comp equivalent: ((comp #(+ 1 %) #(+ % 1) inc) 5)
;; standard equivalent (+ 1 (+ (inc 5) 1))

user=> (->>> 5 inc #(+ % 1) #(+ 1 %)) ;;5 is the input
=> 8


;; comp equivalent: ((comp inc second reverse) '("a" 2 8 "b"))
;; standard equivalent (inc (second (reverse '("a" 2 8 "b"))))

user=> (->>> '("a" 2 8 "b") reverse second inc) ;;'("a" 2 8 "b") is the input
=> 9

nth-safe

(def coll [1 2 3 4 5])

user=> (nth-safe coll 0)
=> 1

user=> (nth-safe coll 12)
=> nil

user=> (nth-safe coll 12 "not-found-value")
=> "not-found-value"

nnth

(nnth [1 [2 3 [4 5]]] 1 2 1)
=> 5

def-

(def- my-coll [1 2 3])
=> #'kezban.core/my-coll

(:private (meta #'kezban.core/my-coll))
=> true

xor

(xor false true nil)
=> true

(xor false nil)
=> nil

pprint-macro

(pprint-macro (when-let [a 1]
                (println a)))
(let*
 [temp__4657__auto__ 1]
 (if temp__4657__auto__ (do (let* [a temp__4657__auto__] (println a)))))
=> nil

quoted?

(quoted? '(+ 1  2))
=> true

(quoted? (+ 1  2))
=> false

array?

(array? (int-array 1))
=> true

(array? :int (int-array 1))
=> true

lazy?

(lazy? (map inc [1 2 3]))
=> true

any-pred

(filter (any-pred even? odd?) [2 4 5 7])
=> (2 4 5 7)

try-> and try->>

(try-> 5 inc dec str inc) ;;also thread last version: try->>
=> nil

multi-comp

(def data [{:v 12, :a 10} {:v 21, :a 113} {:v 1, :a 2} {:v 12, :a 223} {:v 100, :a 23} {:v 1, :a 113}])

(sort #(multi-comp [:a :v] > %1 %2) data)
;or
(sort #(multi-comp [:a :v] %2 %1) data)
=> ({:v 12, :a 223} {:v 21, :a 113} {:v 1, :a 113} {:v 100, :a 23} {:v 12, :a 10} {:v 1, :a 2})

with-out

(with-out 
 (println "Normal out") 
 (.println (System/err) "Error occurred!"))
=> {:err "Error occurred!\n", :out "Normal out\n"}

letm

(letm [a 1
       b (+ a 1)])
=> {:a 1, :b 2}

in?

(in? 3 [1 2 3 4])
=> true

take-while-and-n-more

(take-while-and-n-more even? 2 [2 4 6 7 9 13 15])
=> (2 4 6 7 9)

dissoc-in

(dissoc-in {:a {:b {:c 1 :d 2}}} [:a :b :d])
=> {:a {:b {:c 1}}}

with-timeout

(with-timeout 100
              (Thread/sleep 1500))
=> CompilerException java.util.concurrent.TimeoutException

(with-timeout 1000
              (Thread/sleep 500)
              5)
=> 5

url->file

(url->file "http://file.url" (io/file "your file path to get content"))
=> returns your file instance

cond-let

(cond-let [a 5
           b (+ a 1)]

          (even? a)
          (println "a is odd")

          (even? b)
          (println "b is even"))
b is even
=> nil

keywordize

(keywordize "hey Whats Up?")
=> :hey-whats-up?

source-clj-file

(source-clj-file 'clojure.string)
=> returns clojure.string's namespace source code in string

time*

;;unlike time, time* allows you to provide more than one form
(time* 
  (Thread/sleep 2500)
  12)
  
=> {:duration 2505.328818, :result 12}

process-lazy-seq

(process-lazy-seq (fn [i]
                    (println (inc i))) 10000 (range))
                    
;; we can process 10000 data at time and not getting OutOfMemory Exception

when-no-aot

;; binding will happen when *compile-files* set to false
(def db-conn (when-no-aot (create-db-connection!)))

defay

(defay current-time  (println "Hi!") (System/currentTimeMillis))
;; Hi!
;;=> 1587327846466

@current-time

;;=> 1587327846466

;; Expands to this:
(def current-time (delay (println "Hi!")
                         (System/currentTimeMillis)))

(when-not *compile-files* @current-time)

locals

(defn my-fn
  [a]
  (let [b 2]
    (locals)))

(my-fn 1)
;;=> {a 1, b 2}

prog1

(prog1 (+ 1 2)
  (println "Result: " <>))

;;Result:  3
;;=> 3

defm

(defm my-add [x y]
  (println "Result: " (+ x y))
  (+ x y))

(my-add 1 2)
;;Result:  3
;;=> 3

(my-add 1 2)
;;=> 3

Memoized function, expands to this:

(def my-add
  (memoize
    (fn [x y]
      (println "Result: " (+ x y))
      (+ x y))))

License

  Copyright © 2022 Ertuğrul Çetin
  
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
  
  http://www.apache.org/licenses/LICENSE-2.0
  
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.