application/octet-stream
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1.84 KB
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52 lines
;;; Nujel - Copyright (C) 2020-2021 - Benjamin Vincent Schulenburg
;;; This project uses the MIT license, a copy should be included under /LICENSE
;;;
;;; A bunch of procedurs that work on all collections where the collection primitives are implemented
[defn sum [c]
"Return the sum of every value in collection C"
[reduce c + 0]]
[defn every? [l p]
"Returns #t if P is true for every entry of collection L"
[reduce l [fn [a b] [and a [p b]]] #t]]
[defn join [l glue]
"Join every element of α together into a string with GLUE inbetween"
[when-not glue [set! glue ""]]
[if-not l "" [reduce l [fn [a b] [if a [cat a glue b] b]] #nil]]]
[defn for-each [l f]
"Runs F over every item in collection L"
[reduce l [fn [a b] [f b]] #nil]]
[defn count [l p]
"Count the number of items in L where P is true"
[if p
[reduce l [fn [a b] [+ a [if [p b] 1 0]]] 0]
[reduce l [fn [a b] [+ a 1]] 0]]]
[defn min l
"Returns the minimum value of its arguments"
[reduce l [fn [a b] [if [< a b] a b]]]]
[defn max l
"Returns the maximum value of its arguments"
[reduce l [fn [a b] [if [> a b] a b]]]]
[defn delete [l e]
"Returns a filtered list l with all elements equal to e omitted"
[filter l [fn [a] [not [= a e]]]]]
[defn remove [l p]
"Returns a filtered list l with all elements where P equal true removed"
[filter l [fn [a] [not [p a]]]]]
[def flatten [let*
[defn flatten-λ [a b]
[cond [[collection? b ] [append [reduce b flatten-λ #nil] a]]
[#t [cons b a]]]]
[defn flatten [l]
"Flatten a collection of collections into a simple list"
[if-not [collection? l] l
[nreverse [reduce l flatten-λ #nil]]]]]]
