From f529e14b0443708292a506b3dcc01d0bdb093013 Mon Sep 17 00:00:00 2001 From: takaomag Date: Thu, 2 Jul 2015 14:32:13 +0000 Subject: [PATCH 1/2] Fix algorithm.reversed to accept non-zero 'first' arg --- lib/pure/algorithm.nim | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/lib/pure/algorithm.nim b/lib/pure/algorithm.nim index e087b5ac9..899420fca 100644 --- a/lib/pure/algorithm.nim +++ b/lib/pure/algorithm.nim @@ -50,12 +50,12 @@ proc reverse*[T](a: var openArray[T]) = proc reversed*[T](a: openArray[T], first, last: Natural): seq[T] = ## returns the reverse of the array `a[first..last]`. - result = newSeq[T](last - first + 1) + var i = last - first var x = first.int - var y = last.int - while x <= last: - result[x] = a[y] - dec(y) + result = newSeq[T](i + 1) + while i >= 0: + result[i] = a[x] + dec(i) inc(x) proc reversed*[T](a: openArray[T]): seq[T] = From 101e78df3bc3c90644a9c2aa797e043b3164fcf3 Mon Sep 17 00:00:00 2001 From: takaomag Date: Thu, 2 Jul 2015 16:39:53 +0000 Subject: [PATCH 2/2] Add tests for algorithm.reversed --- lib/pure/algorithm.nim | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/lib/pure/algorithm.nim b/lib/pure/algorithm.nim index 899420fca..76531dac4 100644 --- a/lib/pure/algorithm.nim +++ b/lib/pure/algorithm.nim @@ -361,4 +361,10 @@ when isMainModule: assert srt3.isSorted(cmp) == true var srtseq = newSeq[int]() assert srtseq.isSorted(cmp) == true + # Tests for reversed + var arr1 = @[0,1,2,3,4] + assert arr1.reversed() == @[4,3,2,1,0] + for i in 0 .. high(arr1): + assert arr1.reversed(0, i) == arr1.reversed()[high(arr1) - i .. high(arr1)] + assert arr1.reversed(i, high(arr1)) == arr1.reversed()[0 .. high(arr1) - i]