2ffacb7 · elk · git.iko.soy

git.iko.soy/elk

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Add init function

2ffacb7erdeszt13 years ago

libraries/List.elm+7−1

compare with master

unifiedsplit

@@ -7,7 +7,7 @@ list must have the same type.

7@docs (::), (++), isEmpty, length, reverse, map

9# Sub-lists

10−@docs head, tail, last, filter, take, drop

10+@docs head, tail, last, init, filter, take, drop

12# Putting Lists Together

13@docs concat, concatMap, join, intersperse, zip, zipWith

@@ -58,6 +58,12 @@ tail = Native.List.tail

58last : [a] -> a

59last = Native.List.last

61+{-| Extract the elements before the last element in the list. List must be non-empty.

62+`(init [1,2,3] == [1,2])

63+-}

64+init : [a] -> [a]

65+init = Native.List.init

66+

61{-| Check if a list is empty `(isEmpty [] == True)` -}

67{-| Check if a list is empty `(isEmpty [] == True)` -}

62isEmpty : [a] -> Bool

68isEmpty : [a] -> Bool

63isEmpty xs =

69isEmpty xs =

libraries/Native/List.js+14

@@ -81,6 +81,19 @@ Elm.Native.List.make = function(elm) {

81 return out;

82 }

84+ function init(xs) {

85+ if (xs.ctor === '[]') { throwError('init'); }

86+ var root = Cons(xs._0, Nil);

87+ var curr = root;

88+ xs = xs._1;

89+ while (xs._1.ctor !== '[]') {

90+ curr._1 = Cons(xs._0, Nil)

91+ xs = xs._1

92+ curr = curr._1

93+ }

94+ return root;

95+ }

96+

84 function map(f, xs) {

97 function map(f, xs) {

85 var arr = [];

98 var arr = [];

86 while (xs.ctor !== '[]') {

99 while (xs.ctor !== '[]') {

@@ -278,6 +291,7 @@ Elm.Native.List.make = function(elm) {

278 head:head,

291 head:head,

279 tail:tail,

292 tail:tail,

280 last:last,

293 last:last,

294+ init:init,

281

295

282 map:F2(map),

296 map:F2(map),

283 foldl:F3(foldl),

297 foldl:F3(foldl),