diff options
Diffstat (limited to 'lib/system/iterators.nim')
| -rw-r--r-- | lib/system/iterators.nim | 88 |
1 files changed, 51 insertions, 37 deletions
diff --git a/lib/system/iterators.nim b/lib/system/iterators.nim index d8af4eed5..125bee98f 100644 --- a/lib/system/iterators.nim +++ b/lib/system/iterators.nim @@ -1,14 +1,24 @@ -when defined(nimHasLentIterators) and not defined(nimWorkaround14447): +## Default iterators for some Nim types. + +when defined(nimPreviewSlimSystem): + import std/assertions + +when not defined(nimNoLentIterators): template lent2(T): untyped = lent T else: template lent2(T): untyped = T +template unCheckedInc(x) = + {.push overflowChecks: off.} + inc(x) + {.pop.} + iterator items*[T: not char](a: openArray[T]): lent2 T {.inline.} = ## Iterates over each item of `a`. var i = 0 while i < len(a): yield a[i] - inc(i) + unCheckedInc(i) iterator items*[T: char](a: openArray[T]): T {.inline.} = ## Iterates over each item of `a`. @@ -18,32 +28,32 @@ iterator items*[T: char](a: openArray[T]): T {.inline.} = var i = 0 while i < len(a): yield a[i] - inc(i) + unCheckedInc(i) iterator mitems*[T](a: var openArray[T]): var T {.inline.} = ## Iterates over each item of `a` so that you can modify the yielded value. var i = 0 while i < len(a): yield a[i] - inc(i) + unCheckedInc(i) iterator items*[IX, T](a: array[IX, T]): T {.inline.} = ## Iterates over each item of `a`. - var i = low(IX) - if i <= high(IX): + when a.len > 0: + var i = low(IX) while true: yield a[i] if i >= high(IX): break - inc(i) + unCheckedInc(i) iterator mitems*[IX, T](a: var array[IX, T]): var T {.inline.} = ## Iterates over each item of `a` so that you can modify the yielded value. - var i = low(IX) - if i <= high(IX): + when a.len > 0: + var i = low(IX) while true: yield a[i] if i >= high(IX): break - inc(i) + unCheckedInc(i) iterator items*[T](a: set[T]): T {.inline.} = ## Iterates over each element of `a`. `items` iterates only over the @@ -51,8 +61,11 @@ iterator items*[T](a: set[T]): T {.inline.} = ## able to hold). var i = low(T).int while i <= high(T).int: - if T(i) in a: yield T(i) - inc(i) + when T is enum and not defined(js): + if cast[T](i) in a: yield cast[T](i) + else: + if T(i) in a: yield T(i) + unCheckedInc(i) iterator items*(a: cstring): char {.inline.} = ## Iterates over each item of `a`. @@ -71,7 +84,7 @@ iterator items*(a: cstring): char {.inline.} = let n = len(a) while i < n: yield a[i] - inc(i) + unCheckedInc(i) when defined(js): impl() else: when nimvm: @@ -81,7 +94,7 @@ iterator items*(a: cstring): char {.inline.} = var i = 0 while a[i] != '\0': yield a[i] - inc(i) + unCheckedInc(i) iterator mitems*(a: var cstring): var char {.inline.} = ## Iterates over each item of `a` so that you can modify the yielded value. @@ -89,6 +102,7 @@ iterator mitems*(a: var cstring): var char {.inline.} = runnableExamples: from std/sugar import collect var a = "abc\0def" + prepareMutation(a) var b = a.cstring let s = collect: for bi in mitems(b): @@ -103,7 +117,7 @@ iterator mitems*(a: var cstring): var char {.inline.} = let n = len(a) while i < n: yield a[i] - inc(i) + unCheckedInc(i) when defined(js): impl() else: when nimvm: impl() @@ -111,7 +125,7 @@ iterator mitems*(a: var cstring): var char {.inline.} = var i = 0 while a[i] != '\0': yield a[i] - inc(i) + unCheckedInc(i) iterator items*[T: enum and Ordinal](E: typedesc[T]): T = ## Iterates over the values of `E`. @@ -134,7 +148,7 @@ iterator pairs*[T](a: openArray[T]): tuple[key: int, val: T] {.inline.} = var i = 0 while i < len(a): yield (i, a[i]) - inc(i) + unCheckedInc(i) iterator mpairs*[T](a: var openArray[T]): tuple[key: int, val: var T]{.inline.} = ## Iterates over each item of `a`. Yields `(index, a[index])` pairs. @@ -142,26 +156,26 @@ iterator mpairs*[T](a: var openArray[T]): tuple[key: int, val: var T]{.inline.} var i = 0 while i < len(a): yield (i, a[i]) - inc(i) + unCheckedInc(i) iterator pairs*[IX, T](a: array[IX, T]): tuple[key: IX, val: T] {.inline.} = ## Iterates over each item of `a`. Yields `(index, a[index])` pairs. - var i = low(IX) - if i <= high(IX): + when a.len > 0: + var i = low(IX) while true: yield (i, a[i]) if i >= high(IX): break - inc(i) + unCheckedInc(i) iterator mpairs*[IX, T](a: var array[IX, T]): tuple[key: IX, val: var T] {.inline.} = ## Iterates over each item of `a`. Yields `(index, a[index])` pairs. ## `a[index]` can be modified. - var i = low(IX) - if i <= high(IX): + when a.len > 0: + var i = low(IX) while true: yield (i, a[i]) if i >= high(IX): break - inc(i) + unCheckedInc(i) iterator pairs*[T](a: seq[T]): tuple[key: int, val: T] {.inline.} = ## Iterates over each item of `a`. Yields `(index, a[index])` pairs. @@ -169,7 +183,7 @@ iterator pairs*[T](a: seq[T]): tuple[key: int, val: T] {.inline.} = let L = len(a) while i < L: yield (i, a[i]) - inc(i) + unCheckedInc(i) assert(len(a) == L, "the length of the seq changed while iterating over it") iterator mpairs*[T](a: var seq[T]): tuple[key: int, val: var T] {.inline.} = @@ -179,7 +193,7 @@ iterator mpairs*[T](a: var seq[T]): tuple[key: int, val: var T] {.inline.} = let L = len(a) while i < L: yield (i, a[i]) - inc(i) + unCheckedInc(i) assert(len(a) == L, "the length of the seq changed while iterating over it") iterator pairs*(a: string): tuple[key: int, val: char] {.inline.} = @@ -188,7 +202,7 @@ iterator pairs*(a: string): tuple[key: int, val: char] {.inline.} = let L = len(a) while i < L: yield (i, a[i]) - inc(i) + unCheckedInc(i) assert(len(a) == L, "the length of the string changed while iterating over it") iterator mpairs*(a: var string): tuple[key: int, val: var char] {.inline.} = @@ -198,7 +212,7 @@ iterator mpairs*(a: var string): tuple[key: int, val: var char] {.inline.} = let L = len(a) while i < L: yield (i, a[i]) - inc(i) + unCheckedInc(i) assert(len(a) == L, "the length of the string changed while iterating over it") iterator pairs*(a: cstring): tuple[key: int, val: char] {.inline.} = @@ -208,12 +222,12 @@ iterator pairs*(a: cstring): tuple[key: int, val: char] {.inline.} = var L = len(a) while i < L: yield (i, a[i]) - inc(i) + unCheckedInc(i) else: var i = 0 while a[i] != '\0': yield (i, a[i]) - inc(i) + unCheckedInc(i) iterator mpairs*(a: var cstring): tuple[key: int, val: var char] {.inline.} = ## Iterates over each item of `a`. Yields `(index, a[index])` pairs. @@ -223,12 +237,12 @@ iterator mpairs*(a: var cstring): tuple[key: int, val: var char] {.inline.} = var L = len(a) while i < L: yield (i, a[i]) - inc(i) + unCheckedInc(i) else: var i = 0 while a[i] != '\0': yield (i, a[i]) - inc(i) + unCheckedInc(i) iterator items*[T](a: seq[T]): lent2 T {.inline.} = ## Iterates over each item of `a`. @@ -236,7 +250,7 @@ iterator items*[T](a: seq[T]): lent2 T {.inline.} = let L = len(a) while i < L: yield a[i] - inc(i) + unCheckedInc(i) assert(len(a) == L, "the length of the seq changed while iterating over it") iterator mitems*[T](a: var seq[T]): var T {.inline.} = @@ -245,7 +259,7 @@ iterator mitems*[T](a: var seq[T]): var T {.inline.} = let L = len(a) while i < L: yield a[i] - inc(i) + unCheckedInc(i) assert(len(a) == L, "the length of the seq changed while iterating over it") iterator items*(a: string): char {.inline.} = @@ -254,7 +268,7 @@ iterator items*(a: string): char {.inline.} = let L = len(a) while i < L: yield a[i] - inc(i) + unCheckedInc(i) assert(len(a) == L, "the length of the string changed while iterating over it") iterator mitems*(a: var string): var char {.inline.} = @@ -263,7 +277,7 @@ iterator mitems*(a: var string): var char {.inline.} = let L = len(a) while i < L: yield a[i] - inc(i) + unCheckedInc(i) assert(len(a) == L, "the length of the string changed while iterating over it") @@ -304,7 +318,7 @@ iterator fieldPairs*[T: tuple|object](x: T): tuple[key: string, val: RootObj] {. ## picking the appropriate code to a secondary proc which you overload for ## each field type and pass the `value` to. ## - ## .. warning::: This really transforms the 'for' and unrolls the loop. The + ## .. warning:: This really transforms the 'for' and unrolls the loop. The ## current implementation also has a bug that affects symbol binding in the ## loop body. runnableExamples: |