application/octet-stream
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5.84 KB
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203 lines
;; Nujel - Copyright (C) 2020-2021 - Benjamin Vincent Schulenburg
;; This project uses the MIT license, a copy should be included under /LICENSE
;; Put all the LISt Processing stuff in here
[defn array->list [arr]
[def i [- [array/length arr] 1]]
[def ret #nil]
[while [>= i 0]
[set! ret [cons [array/ref arr i] ret]]
[-- i]]
[return ret]]
[defn except-last-pair/iter [list rest]
"Iterator for except-last-pair"
[if [nil? [cdr list]]
[reverse rest]
[except-last-pair/iter [cdr list] [cons [car list] rest]]]]
[defn except-last-pair [list]
"Return a copy of LIST without the last pair"
[except-last-pair/iter list #nil]]
[defn last-pair [list]
"Return the last pair of LIST"
[while [cdr list]
[cdr! list]]
list]
[defn make-list [number value]
"Return a list of NUMBER elements containing VALUE in every car"
[def list #nil]
[while [>= [-- number] 0]
[set! list [cons value list]]]
list]
[defn range [end start step]
"Return a list containing values from START (inclusive) to END (exclusive) by STEP"
[when-not end [throw [list :arity-error "[range] needs at least a specific end"]]]
[when-not start [set! start 0]]
[when-not step [set! step 1]]
[def pred [if [pos? step] < >]]
[def ret #nil]
[while [pred start end]
[set! ret [cons start ret]]
[set! start [+ start step]]]
[nreverse ret]]
[defn list/reduce [l o s]
"Combine all elements in l using operation o and starting value s"
[for-in [e l]
[set! s [o s e]]]
s]
[defn list/ref [l i]
"Returns the the element of list l at location i"
[while [and l [> i 0]]
[-- i]
[cdr! l]]
[car l]]
[defn reverse [l]
"Return the list l in reverse order"
[def ret]
[for-in [e l]
[set! ret [cons e ret]]]
ret]
[defn list/length [l]
"Returns the length of list l"
[def ret 0]
[for-in [e l]
[++ ret]]
ret]
[defn list/filter [l p]
"Runs predicate p over every item in list l and returns a list consiting solely of items where p is true"
[def ret #nil]
[for-in [e l]
[when [p e]
[set! ret [cons e ret]]]]
[nreverse ret]]
[defn list/map [l f]
"Runs f over every item in list l and returns the resulting list"
[def ret #nil]
[for-in [e l]
[set! ret [cons [f e] ret]]]
[nreverse ret]]
[defn append [a b]
"Appends two lists A and B together"
[def ret b]
[set! a [reverse a]]
[for-in [t a]
[set! ret [cons t ret]]]
ret]
[defn sublist [l start end ret]
"Returns a new list containing all elements of l from start to end"
[cond [[nil? l] [reverse ret]]
[[neg? end] [sublist l start [+ [length l] end]]]
[[zero? end] [reverse ret]]
[[> start 0] [sublist [cdr l] [+ -1 start] [+ -1 end] #nil]]
[[> end 0] [sublist [cdr l] 0 [+ -1 end] [cons [car l] ret]]]]]
[defn list-head [l k]
"Returns the first k elements of list l"
[sublist l 0 k]]
[defn list-tail [l k]
"Returns the sublist of l obtained by omitting the first l elements"
[sublist l k [length l]]]
[defn list/member [l m]
"Returns the first pair of list l whose car is equal to m"
[cond [[nil? l] #f]
[[== [car l] m] l]
[#t [list/member [cdr l] m]]]]
[defn getf [l key]
"Return the value in LIST following KEY"
[cond [[nil? l] #nil]
[[== key [car l]] [cadr l]]
[#t [getf [cdr l] key]]]]
[defn list/sort/bubble [l]
"Terribly slow way to sort a list, though it was simple to write"
[if-not l #nil
[do [def top [car l]]
[def next #nil]
[cdr! l]
[while l
[if [<= [car l] top]
[do [set! next [cons top next]]
[set! top [car l]]]
[set! next [cons [car l] next]]]
[cdr! l]]
[cons top [list/sort/bubble next]]]]]
[defn list/merge-sorted-lists [l1 l2]
[cond [[nil? l1] l2]
[[nil? l2] l1]
[#t [if [< [car l1] [car l2]]
[cons [car l1] [list/merge-sorted-lists [cdr l1] l2]]
[cons [car l2] [list/merge-sorted-lists l1 [cdr l2]]]]]]]
[defn list/split-half-rec [l acc1 acc2]
[cond [[nil? l] [cons acc1 acc2]]
[[nil? [cdr l]] [cons [cons [car l] acc1] acc2]]
[#t [list/split-half-rec [cddr l] [cons [car l] acc1] [cons [cadr l] acc2]]]]]
[defn list/split-half [l] [list/split-half-rec l #nil #nil]]
[defn list/sort/merge [l]
"Sorts a list"
[if [nil? [cdr l]]
l
[do [def parts [list/split-half l]]
[list/merge-sorted-lists
[list/sort/merge [car parts]]
[list/sort/merge [cdr parts]]]]]]
; Set default sort to merge-sort
[def list/sort list/sort/merge]
[defn list/equal? [a b]
"#t if A and B are equal"
[if [pair? a]
[and [list/equal? [car a] [car b]]
[list/equal? [cdr a] [cdr b]]]
[equal? a b]]]
[defn list/take [l count]
"Take the first COUNT elements from list L"
[if [<= count 0]
#nil
[cons [car l] [list/take [cdr l] [- count 1]]]]]
[defn list/drop [l count]
"Drop the final COUNT elements from list L"
[if [<= count 0]
l
[list/drop [cdr l] [- count 1]]]]
[defn list/cut [l start end]
"Return a subsequence of L from START to END"
[list/take [list/drop l [max 0 start]] [- end [max 0 start]]]]
[defn list/replace [l search-for replace-with]
"Return a new list where every occurence of SEARCH-FOR is replaced with REPLACE-WITH"
""
"Uses [equal?] so we can search/replace lists/trees and other complex data structures"
[cond [[not l] #nil]
[[equal? l search-for]
replace-with]
[[equal? [car l] search-for]
[cons replace-with
[list/replace [cdr l] search-for replace-with]]]
[#t [cons [if [pair? [car l]]
[list/replace [car l] search-for replace-with]
[car l]]
[list/replace [cdr l] search-for replace-with]]]]]
