b471661 · elk · git.iko.soy

Simplify Trampoline datatype.

commitb47166144d33a330cbfbf7e6a2b9330aff9d1de2 authorMax New <maxsnew@gmail.com> dateMon 20 Jan 2014, 14:38 (13 years ago) parent84aab58

2 files changed+8−9

unifiedsplit

libraries/Native/Trampoline.js+5−5

@@ -10,11 +10,11 @@ Elm.Native.Trampoline.make = function(elm) {

1010 trampoline = function(t) {

1111 var tramp = t;

1212 while(true) {

13− switch(tramp._0.ctor) {

14− case "Left":

15− return tramp._0._0;

16− case "Right":

17− tramp = tramp._0._0({ctor: "_Tuple0"});

13+ switch(tramp.ctor) {

14+ case "Done":

15+ return tramp._0;

16+ case "Continue":

17+ tramp = tramp._0({ctor: "_Tuple0"});

1818 continue;

1919 }

2020 _E.Case("Trampoline", "in Native.Trampoline.trampoline");

libraries/Trampoline.elm+3−4

@@ -1,5 +1,4 @@

1−module Trampoline (Trampoline, trampoline)

2− where

1+module Trampoline where

43{-| Trampolining loops for unbounded recursion.

54Since most javascript implementations lack tail-call elimination, deeply tail-recursive functions will result in a stack overflow.

@@ -33,10 +32,10 @@ main = asText <| fac 1000000000000

3332@docs Trampoline, trampoline

3433 -}

3534import Native.Trampoline

36−import open Either

3735

3836{-| A computation that might loop. A trampoline is either the resulting value or a thunk that needs to be run more. -}

39−data Trampoline a = Trampoline (Either a (() -> Trampoline a))

37+data Trampoline a = Done a

38+ | Continue (() -> Trampoline a)

4039

4140{-| Run a trampolining loop in constant space. -}

4241trampoline : Trampoline a -> a