Tól

Tól is a set of functions that extend Clojure/ClojureScript core functions. A lot of Clojure core functions are just wrappers over Java classes/methods. Thus these functions are more Java-like (they throw NullPointerException), but this behaviour isn't expected in Clojure world. Clojure's functions for sequences aren't NPE-prone, but others do (e.g. string module). All Tól functions are designed not to be NPE-prone (rather return nil, instead of throw NPE) thus they can be used e.g. in some-> macro.

Leiningen/Boot

[tol "0.9.0"]

Documentation

->int

Coerce a given input as an integer. If the input is not an integer it returns nil.

(tol/->int 1) ;; 1
(tol/->int "1") ;; 1
(tol/->int nil) ;; nil
(tol/->int "") ;; nil

->uuid

Coerce a given value as java.util.UUID. When the value is not a valid UUID, it returns nil. In ClojureScript there is not UUID class/function (not even in Google Closure Library). Thus in ClojureScript it returns just string value for non-blank value.

(tol/->uuid "59537428-0b92-4d3a-9192-bcbae9a18889") ;; #uuid "59537428-0b92-4d3a-9192-bcbae9a18889"
(tol/->uuid nil) ;; nil
(tol/->uuid "") ;; nil
(tol/->uuid "asdf") ;; nil

lowerf

Lower cases first character of a given value. It's safe, when the value is nil or empty string returns nil, otherwise string.

(tol/lowerf nil) ;; nil
(tol/lowerf "") ;; nil
(tol/lowerf "ABC") ;; "aBC"

upperf

Upper cases first character of a given value. It's safe, when the value is nil or empty string returns nil, otherwise string.

(tol/upperf nil) ;; nil
(tol/upperf "") ;; nil
(tol/upperf "abC") ;; "AbC"

if-let*

It's if-let with multiple bindings. It allows to flatten and simplify some code nesting.

It doesn't work in ClojureScript.

(tol/if-let*
  [a 1
   b (+ a 1)]
  b) ;; 2

(tol/if-let*
  [a 1
   b (+ a 1)
   c false]
  :then
  :else) ;; :else

(tol/if-let*
  [a 1
   b nil]
  a) ;; nil

non-blank

Return a given input when it isn't nil. Otherwise nil is returned. It's useful for some-> macros.

(tol/non-blank nil) ;; nil
(tol/non-blank "") ;; nil
(tol/non-blank " ") ;; nil
(tol/non-blank "abC") ;; "AbC"

update-keys

Applies a given function f on every key in a given associative structure m, where f is a function that will take a key-name and any supplied args and return new value.

(tol/update-keys inc {0 :a}) ;; {1 :a}
(tol/update-keys inc nil) ;; nil
(tol/update-keys inc {}) ;; nil
(tol/update-keys + 2 {0 :a}) ;; {2 :a}
(tol/update-keys + 2 1 {0 :a}) ;; {3 :a}
(tol/update-keys + 3 2 1 {0 :a}) ;; {6 :a}
(tol/update-keys (fn [init a b c more] (apply + (concat [init a b c] more))) 4 3 2 [1] {0 :a}) ;; {10 :a}

update-vals

Applies a given function f on every value in a given coll

(tol/update-vals inc {:a 0}) ;; {:a 1}
(tol/update-vals inc nil) ;; nil
(tol/update-vals inc {}) ;; {}

case+

Same as case, but evaluates dispatch values, needed for referring to class and defined constants as well as java.util.Enum instances.

It doesn't work in ClojureScript.

(tol/case+ java.util.concurrent.TimeUnit/SECONDS
  java.util.concurrent.TimeUnit/SECONDS :seconds
  nil) ;; :seconds

(tol/case+ nil
  java.util.concurrent.TimeUnit/SECONDS :seconds
  nil) ;; nil

(tol/case+ 1
  java.util.concurrent.TimeUnit/SECONDS :seconds
  nil) ;; nil

Contribution

Conventions

• Please follow coding style defined by .editorconfig and The Clojure Style Guide
• Write good commit messages and provide an issue ID in a commit message prefixed by #