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Diffstat (limited to 'lib/pure/collections/sequtils.nim')
| -rw-r--r-- | lib/pure/collections/sequtils.nim | 331 |
1 files changed, 197 insertions, 134 deletions
diff --git a/lib/pure/collections/sequtils.nim b/lib/pure/collections/sequtils.nim index 7aa885794..3c0d8dc0e 100644 --- a/lib/pure/collections/sequtils.nim +++ b/lib/pure/collections/sequtils.nim @@ -8,13 +8,13 @@ # ## Although this module has `seq` in its name, it implements operations -## not only for `seq`:idx: type, but for three built-in container types under -## the `openArray` umbrella: +## not only for the `seq`:idx: type, but for three built-in container types +## under the `openArray` umbrella: ## * sequences ## * strings ## * array ## -## The system module defines several common functions, such as: +## The `system` module defines several common functions, such as: ## * `newSeq[T]` for creating new sequences of type `T` ## * `@` for converting arrays and strings to sequences ## * `add` for adding new elements to strings and sequences @@ -27,28 +27,28 @@ ## languages. ## ## For functional style programming you have different options at your disposal: -## * `sugar.collect macro<sugar.html#collect.m%2Cuntyped%2Cuntyped>`_ -## * pass `anonymous proc<manual.html#procedures-anonymous-procs>`_ -## * import `sugar module<sugar.html>`_ and use -## `=> macro<sugar.html#%3D>.m,untyped,untyped>`_ +## * the `sugar.collect macro<sugar.html#collect.m%2Cuntyped%2Cuntyped>`_ +## * pass an `anonymous proc<manual.html#procedures-anonymous-procs>`_ +## * import the `sugar module<sugar.html>`_ and use +## the `=> macro<sugar.html#%3D>.m,untyped,untyped>`_ ## * use `...It templates<#18>`_ ## (`mapIt<#mapIt.t,typed,untyped>`_, ## `filterIt<#filterIt.t,untyped,untyped>`_, etc.) ## -## The chaining of functions is possible thanks to the +## Chaining of functions is possible thanks to the ## `method call syntax<manual.html#procedures-method-call-syntax>`_. runnableExamples: - import sugar + import std/sugar # Creating a sequence from 1 to 10, multiplying each member by 2, # keeping only the members which are not divisible by 6. let - foo = toSeq(1..10).map(x => x*2).filter(x => x mod 6 != 0) - bar = toSeq(1..10).mapIt(it*2).filterIt(it mod 6 != 0) + foo = toSeq(1..10).map(x => x * 2).filter(x => x mod 6 != 0) + bar = toSeq(1..10).mapIt(it * 2).filterIt(it mod 6 != 0) baz = collect: for i in 1..10: - let j = 2*i + let j = 2 * i if j mod 6 != 0: j @@ -62,7 +62,7 @@ runnableExamples: runnableExamples: - from strutils import join + from std/strutils import join let vowels = @"aeiou" @@ -71,7 +71,8 @@ runnableExamples: doAssert (vowels is seq[char]) and (vowels == @['a', 'e', 'i', 'o', 'u']) doAssert foo.filterIt(it notin vowels).join == "sqtls s n wsm mdl" -## **See also**: +## See also +## ======== ## * `strutils module<strutils.html>`_ for common string functions ## * `sugar module<sugar.html>`_ for syntactic sugar macros ## * `algorithm module<algorithm.html>`_ for common generic algorithms @@ -81,20 +82,26 @@ runnableExamples: import std/private/since -import macros +import std/macros +from std/typetraits import supportsCopyMem -when not defined(nimhygiene): - {.pragma: dirty.} +when defined(nimPreviewSlimSystem): + import std/assertions +when defined(nimHasEffectsOf): + {.experimental: "strictEffects".} +else: + {.pragma: effectsOf.} + macro evalOnceAs(expAlias, exp: untyped, letAssigneable: static[bool]): untyped = ## Injects `expAlias` in caller scope, to avoid bugs involving multiple - ## substitution in macro arguments such as - ## https://github.com/nim-lang/Nim/issues/7187 + ## substitution in macro arguments such as + ## https://github.com/nim-lang/Nim/issues/7187. ## `evalOnceAs(myAlias, myExp)` will behave as `let myAlias = myExp` ## except when `letAssigneable` is false (e.g. to handle openArray) where - ## it just forwards `exp` unchanged + ## it just forwards `exp` unchanged. expectKind(expAlias, nnkIdent) var val = exp @@ -113,7 +120,7 @@ func concat*[T](seqs: varargs[seq[T]]): seq[T] = ## Takes several sequences' items and returns them inside a new sequence. ## All sequences must be of the same type. ## - ## See also: + ## **See also:** ## * `distribute func<#distribute,seq[T],Positive>`_ for a reverse ## operation ## @@ -134,6 +141,22 @@ func concat*[T](seqs: varargs[seq[T]]): seq[T] = result[i] = itm inc(i) +func addUnique*[T](s: var seq[T], x: sink T) = + ## Adds `x` to the container `s` if it is not already present. + ## Uses `==` to check if the item is already present. + runnableExamples: + var a = @[1, 2, 3] + a.addUnique(4) + a.addUnique(4) + assert a == @[1, 2, 3, 4] + + for i in 0..high(s): + if s[i] == x: return + when declared(ensureMove): + s.add ensureMove(x) + else: + s.add x + func count*[T](s: openArray[T], x: T): int = ## Returns the number of occurrences of the item `x` in the container `s`. ## @@ -167,7 +190,7 @@ func cycle*[T](s: openArray[T], n: Natural): seq[T] = result[o] = e inc o -func repeat*[T](x: T, n: Natural): seq[T] = +proc repeat*[T](x: T, n: Natural): seq[T] = ## Returns a new sequence with the item `x` repeated `n` times. ## `n` must be a non-negative number (zero or more). ## @@ -183,7 +206,7 @@ func repeat*[T](x: T, n: Natural): seq[T] = func deduplicate*[T](s: openArray[T], isSorted: bool = false): seq[T] = ## Returns a new sequence without duplicates. ## - ## Setting the optional argument ``isSorted`` to ``true`` (default: false) + ## Setting the optional argument `isSorted` to true (default: false) ## uses a faster algorithm for deduplication. ## runnableExamples: @@ -210,7 +233,7 @@ func deduplicate*[T](s: openArray[T], isSorted: bool = false): seq[T] = func minIndex*[T](s: openArray[T]): int {.since: (1, 1).} = ## Returns the index of the minimum value of `s`. - ## ``T`` needs to have a ``<`` operator. + ## `T` needs to have a `<` operator. runnableExamples: let a = @[1, 2, 3, 4] @@ -227,7 +250,7 @@ func minIndex*[T](s: openArray[T]): int {.since: (1, 1).} = func maxIndex*[T](s: openArray[T]): int {.since: (1, 1).} = ## Returns the index of the maximum value of `s`. - ## ``T`` needs to have a ``<`` operator. + ## `T` needs to have a `<` operator. runnableExamples: let a = @[1, 2, 3, 4] @@ -242,18 +265,27 @@ func maxIndex*[T](s: openArray[T]): int {.since: (1, 1).} = for i in 1..high(s): if s[i] > s[result]: result = i +func minmax*[T](x: openArray[T]): (T, T) = + ## The minimum and maximum values of `x`. `T` needs to have a `<` operator. + var l = x[0] + var h = x[0] + for i in 1..high(x): + if x[i] < l: l = x[i] + if h < x[i]: h = x[i] + result = (l, h) + template zipImpl(s1, s2, retType: untyped): untyped = - func zip*[S, T](s1: openArray[S], s2: openArray[T]): retType = + proc zip*[S, T](s1: openArray[S], s2: openArray[T]): retType = ## Returns a new sequence with a combination of the two input containers. ## ## The input containers can be of different types. ## If one container is shorter, the remaining items in the longer container ## are discarded. ## - ## **Note**: For Nim 1.0.x and older version, ``zip`` returned a seq of - ## named tuple with fields ``a`` and ``b``. For Nim versions 1.1.x and newer, - ## ``zip`` returns a seq of unnamed tuples. + ## **Note**: For Nim 1.0.x and older version, `zip` returned a seq of + ## named tuples with fields `a` and `b`. For Nim versions 1.1.x and newer, + ## `zip` returns a seq of unnamed tuples. runnableExamples: let short = @[1, 2, 3] @@ -287,7 +319,7 @@ when (NimMajor, NimMinor) <= (1, 0): else: zipImpl(s1, s2, seq[(S, T)]) -func unzip*[S, T](s: openArray[(S, T)]): (seq[S], seq[T]) {.since: (1, 1).} = +proc unzip*[S, T](s: openArray[(S, T)]): (seq[S], seq[T]) {.since: (1, 1).} = ## Returns a tuple of two sequences split out from a sequence of 2-field tuples. runnableExamples: let @@ -296,8 +328,7 @@ func unzip*[S, T](s: openArray[(S, T)]): (seq[S], seq[T]) {.since: (1, 1).} = unzipped2 = @['a', 'b', 'c'] assert zipped.unzip() == (unzipped1, unzipped2) assert zip(unzipped1, unzipped2).unzip() == (unzipped1, unzipped2) - result[0] = newSeq[S](s.len) - result[1] = newSeq[T](s.len) + result = (newSeq[S](s.len), newSeq[T](s.len)) for i in 0..<s.len: result[0][i] = s[i][0] result[1][i] = s[i][1] @@ -311,7 +342,7 @@ func distribute*[T](s: seq[T], num: Positive, spread = true): seq[seq[T]] = ## `num` empty sequences. ## ## If `spread` is false and the length of `s` is not a multiple of `num`, the - ## func will max out the first sub-sequence with ``1 + len(s) div num`` + ## func will max out the first sub-sequence with `1 + len(s) div num` ## entries, leaving the remainder of elements to the last sequence. ## ## On the other hand, if `spread` is true, the func will distribute evenly @@ -329,7 +360,6 @@ func distribute*[T](s: seq[T], num: Positive, spread = true): seq[seq[T]] = if num < 2: result = @[s] return - let num = int(num) # XXX probably only needed because of .. bug # Create the result and calculate the stride size and the remainder if any. result = newSeq[seq[T]](num) @@ -360,17 +390,17 @@ func distribute*[T](s: seq[T], num: Positive, spread = true): seq[seq[T]] = first = last proc map*[T, S](s: openArray[T], op: proc (x: T): S {.closure.}): - seq[S]{.inline.} = - ## Returns a new sequence with the results of `op` proc applied to every + seq[S] {.inline, effectsOf: op.} = + ## Returns a new sequence with the results of the `op` proc applied to every ## item in the container `s`. ## - ## Since the input is not modified you can use it to + ## Since the input is not modified, you can use it to ## transform the type of the elements in the input container. ## ## Instead of using `map` and `filter`, consider using the `collect` macro ## from the `sugar` module. ## - ## See also: + ## **See also:** ## * `sugar.collect macro<sugar.html#collect.m%2Cuntyped%2Cuntyped>`_ ## * `mapIt template<#mapIt.t,typed,untyped>`_ ## * `apply proc<#apply,openArray[T],proc(T)_2>`_ for the in-place version @@ -386,15 +416,14 @@ proc map*[T, S](s: openArray[T], op: proc (x: T): S {.closure.}): result[i] = op(s[i]) proc apply*[T](s: var openArray[T], op: proc (x: var T) {.closure.}) - {.inline.} = - ## Applies `op` to every item in `s` modifying it directly. + {.inline, effectsOf: op.} = + ## Applies `op` to every item in `s`, modifying it directly. ## - ## Note that container `s` must be declared as a ``var`` - ## and it is required for your input and output types to - ## be the same, since `s` is modified in-place. - ## The parameter function takes a ``var T`` type parameter. + ## Note that the container `s` must be declared as a `var`, + ## since `s` is modified in-place. + ## The parameter function takes a `var T` type parameter. ## - ## See also: + ## **See also:** ## * `applyIt template<#applyIt.t,untyped,untyped>`_ ## * `map proc<#map,openArray[T],proc(T)>`_ ## @@ -406,15 +435,15 @@ proc apply*[T](s: var openArray[T], op: proc (x: var T) {.closure.}) for i in 0 ..< s.len: op(s[i]) proc apply*[T](s: var openArray[T], op: proc (x: T): T {.closure.}) - {.inline.} = + {.inline, effectsOf: op.} = ## Applies `op` to every item in `s` modifying it directly. ## - ## Note that container `s` must be declared as a ``var`` + ## Note that the container `s` must be declared as a `var` ## and it is required for your input and output types to ## be the same, since `s` is modified in-place. - ## The parameter function takes and returns a ``T`` type variable. + ## The parameter function takes and returns a `T` type variable. ## - ## See also: + ## **See also:** ## * `applyIt template<#applyIt.t,untyped,untyped>`_ ## * `map proc<#map,openArray[T],proc(T)>`_ ## @@ -425,24 +454,25 @@ proc apply*[T](s: var openArray[T], op: proc (x: T): T {.closure.}) for i in 0 ..< s.len: s[i] = op(s[i]) -proc apply*[T](s: openArray[T], op: proc (x: T) {.closure.}) {.inline, since: (1, 3).} = - ## Same as `apply` but for proc that do not return and do not mutate `s` directly. +proc apply*[T](s: openArray[T], op: proc (x: T) {.closure.}) {.inline, since: (1, 3), effectsOf: op.} = + ## Same as `apply` but for a proc that does not return anything + ## and does not mutate `s` directly. runnableExamples: var message: string apply([0, 1, 2, 3, 4], proc(item: int) = message.addInt item) assert message == "01234" for i in 0 ..< s.len: op(s[i]) -iterator filter*[T](s: openArray[T], pred: proc(x: T): bool {.closure.}): T = +iterator filter*[T](s: openArray[T], pred: proc(x: T): bool {.closure.}): T {.effectsOf: pred.} = ## Iterates through a container `s` and yields every item that fulfills the - ## predicate `pred` (function that returns a `bool`). + ## predicate `pred` (a function that returns a `bool`). ## ## Instead of using `map` and `filter`, consider using the `collect` macro ## from the `sugar` module. ## - ## See also: + ## **See also:** ## * `sugar.collect macro<sugar.html#collect.m%2Cuntyped%2Cuntyped>`_ - ## * `fliter proc<#filter,openArray[T],proc(T)>`_ + ## * `filter proc<#filter,openArray[T],proc(T)>`_ ## * `filterIt template<#filterIt.t,untyped,untyped>`_ ## runnableExamples: @@ -457,14 +487,14 @@ iterator filter*[T](s: openArray[T], pred: proc(x: T): bool {.closure.}): T = yield s[i] proc filter*[T](s: openArray[T], pred: proc(x: T): bool {.closure.}): seq[T] - {.inline.} = - ## Returns a new sequence with all the items of `s` that fulfilled the - ## predicate `pred` (function that returns a `bool`). + {.inline, effectsOf: pred.} = + ## Returns a new sequence with all the items of `s` that fulfill the + ## predicate `pred` (a function that returns a `bool`). ## ## Instead of using `map` and `filter`, consider using the `collect` macro ## from the `sugar` module. ## - ## See also: + ## **See also:** ## * `sugar.collect macro<sugar.html#collect.m%2Cuntyped%2Cuntyped>`_ ## * `filterIt template<#filterIt.t,untyped,untyped>`_ ## * `filter iterator<#filter.i,openArray[T],proc(T)>`_ @@ -484,16 +514,16 @@ proc filter*[T](s: openArray[T], pred: proc(x: T): bool {.closure.}): seq[T] result.add(s[i]) proc keepIf*[T](s: var seq[T], pred: proc(x: T): bool {.closure.}) - {.inline.} = - ## Keeps the items in the passed sequence `s` if they fulfilled the - ## predicate `pred` (function that returns a `bool`). + {.inline, effectsOf: pred.} = + ## Keeps the items in the passed sequence `s` if they fulfill the + ## predicate `pred` (a function that returns a `bool`). ## - ## Note that `s` must be declared as a ``var``. + ## Note that `s` must be declared as a `var`. ## ## Similar to the `filter proc<#filter,openArray[T],proc(T)>`_, ## but modifies the sequence directly. ## - ## See also: + ## **See also:** ## * `keepItIf template<#keepItIf.t,seq,untyped>`_ ## * `filter proc<#filter,openArray[T],proc(T)>`_ ## @@ -513,12 +543,51 @@ proc keepIf*[T](s: var seq[T], pred: proc(x: T): bool {.closure.}) inc(pos) setLen(s, pos) -func delete*[T](s: var seq[T]; first, last: Natural) = - ## Deletes in the items of a sequence `s` at positions ``first..last`` - ## (including both ends of a range). - ## This modifies `s` itself, it does not return a copy. +func delete*[T](s: var seq[T]; slice: Slice[int]) = + ## Deletes the items `s[slice]`, raising `IndexDefect` if the slice contains + ## elements out of range. ## + ## This operation moves all elements after `s[slice]` in linear time. runnableExamples: + var a = @[10, 11, 12, 13, 14] + doAssertRaises(IndexDefect): a.delete(4..5) + assert a == @[10, 11, 12, 13, 14] + a.delete(4..4) + assert a == @[10, 11, 12, 13] + a.delete(1..2) + assert a == @[10, 13] + a.delete(1..<1) # empty slice + assert a == @[10, 13] + when compileOption("boundChecks"): + if not (slice.a < s.len and slice.a >= 0 and slice.b < s.len): + raise newException(IndexDefect, $(slice: slice, len: s.len)) + if slice.b >= slice.a: + template defaultImpl = + var i = slice.a + var j = slice.b + 1 + var newLen = s.len - j + i + while i < newLen: + when defined(gcDestructors): + s[i] = move(s[j]) + else: + s[i].shallowCopy(s[j]) + inc(i) + inc(j) + setLen(s, newLen) + when nimvm: defaultImpl() + else: + when defined(js): + let n = slice.b - slice.a + 1 + let first = slice.a + {.emit: "`s`.splice(`first`, `n`);".} + else: + defaultImpl() + +func delete*[T](s: var seq[T]; first, last: Natural) {.deprecated: "use `delete(s, first..last)`".} = + ## Deletes the items of a sequence `s` at positions `first..last` + ## (including both ends of the range). + ## This modifies `s` itself, it does not return a copy. + runnableExamples("--warning:deprecated:off"): let outcome = @[1, 1, 1, 1, 1, 1, 1, 1] var dest = @[1, 1, 1, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1] dest.delete(3, 8) @@ -527,8 +596,8 @@ func delete*[T](s: var seq[T]; first, last: Natural) = if first >= s.len: return var i = first - var j = min(len(s), last+1) - var newLen = len(s)-j+i + var j = min(len(s), last + 1) + var newLen = len(s) - j + i while i < newLen: when defined(gcDestructors): s[i] = move(s[j]) @@ -542,7 +611,7 @@ func insert*[T](dest: var seq[T], src: openArray[T], pos = 0) = ## Inserts items from `src` into `dest` at position `pos`. This modifies ## `dest` itself, it does not return a copy. ## - ## Notice that `src` and `dest` must be of the same type. + ## Note that the elements of `src` and `dest` must be of the same type. ## runnableExamples: var dest = @[1, 1, 1, 1, 1, 1, 1, 1] @@ -573,7 +642,7 @@ func insert*[T](dest: var seq[T], src: openArray[T], pos = 0) = template filterIt*(s, pred: untyped): untyped = - ## Returns a new sequence with all the items of `s` that fulfilled the + ## Returns a new sequence with all the items of `s` that fulfill the ## predicate `pred`. ## ## Unlike the `filter proc<#filter,openArray[T],proc(T)>`_ and @@ -584,9 +653,9 @@ template filterIt*(s, pred: untyped): untyped = ## Instead of using `mapIt` and `filterIt`, consider using the `collect` macro ## from the `sugar` module. ## - ## See also: + ## **See also:** ## * `sugar.collect macro<sugar.html#collect.m%2Cuntyped%2Cuntyped>`_ - ## * `fliter proc<#filter,openArray[T],proc(T)>`_ + ## * `filter proc<#filter,openArray[T],proc(T)>`_ ## * `filter iterator<#filter.i,openArray[T],proc(T)>`_ ## runnableExamples: @@ -604,13 +673,13 @@ template filterIt*(s, pred: untyped): untyped = template keepItIf*(varSeq: seq, pred: untyped) = ## Keeps the items in the passed sequence (must be declared as a `var`) - ## if they fulfilled the predicate. + ## if they fulfill the predicate. ## ## Unlike the `keepIf proc<#keepIf,seq[T],proc(T)>`_, ## the predicate needs to be an expression using ## the `it` variable for testing, like: `keepItIf("abcxyz", it == 'x')`. ## - ## See also: + ## **See also:** ## * `keepIf proc<#keepIf,seq[T],proc(T)>`_ ## * `filterIt template<#filterIt.t,untyped,untyped>`_ ## @@ -633,7 +702,7 @@ template keepItIf*(varSeq: seq, pred: untyped) = since (1, 1): template countIt*(s, pred: untyped): int = - ## Returns a count of all the items that fulfilled the predicate. + ## Returns a count of all the items that fulfill the predicate. ## ## The predicate needs to be an expression using ## the `it` variable for testing, like: `countIt(@[1, 2, 3], it > 2)`. @@ -650,23 +719,23 @@ since (1, 1): if pred: result += 1 result -proc all*[T](s: openArray[T], pred: proc(x: T): bool {.closure.}): bool = +proc all*[T](s: openArray[T], pred: proc(x: T): bool {.closure.}): bool {.effectsOf: pred.} = ## Iterates through a container and checks if every item fulfills the ## predicate. ## - ## See also: + ## **See also:** ## * `allIt template<#allIt.t,untyped,untyped>`_ ## * `any proc<#any,openArray[T],proc(T)>`_ ## runnableExamples: let numbers = @[1, 4, 5, 8, 9, 7, 4] - assert all(numbers, proc (x: int): bool = return x < 10) == true - assert all(numbers, proc (x: int): bool = return x < 9) == false + assert all(numbers, proc (x: int): bool = x < 10) == true + assert all(numbers, proc (x: int): bool = x < 9) == false for i in s: if not pred(i): return false - return true + true template allIt*(s, pred: untyped): bool = ## Iterates through a container and checks if every item fulfills the @@ -676,7 +745,7 @@ template allIt*(s, pred: untyped): bool = ## the predicate needs to be an expression using ## the `it` variable for testing, like: `allIt("abba", it == 'a')`. ## - ## See also: + ## **See also:** ## * `all proc<#all,openArray[T],proc(T)>`_ ## * `anyIt template<#anyIt.t,untyped,untyped>`_ ## @@ -692,33 +761,33 @@ template allIt*(s, pred: untyped): bool = break result -proc any*[T](s: openArray[T], pred: proc(x: T): bool {.closure.}): bool = - ## Iterates through a container and checks if some item fulfills the - ## predicate. +proc any*[T](s: openArray[T], pred: proc(x: T): bool {.closure.}): bool {.effectsOf: pred.} = + ## Iterates through a container and checks if at least one item + ## fulfills the predicate. ## - ## See also: + ## **See also:** ## * `anyIt template<#anyIt.t,untyped,untyped>`_ ## * `all proc<#all,openArray[T],proc(T)>`_ ## runnableExamples: let numbers = @[1, 4, 5, 8, 9, 7, 4] - assert any(numbers, proc (x: int): bool = return x > 8) == true - assert any(numbers, proc (x: int): bool = return x > 9) == false + assert any(numbers, proc (x: int): bool = x > 8) == true + assert any(numbers, proc (x: int): bool = x > 9) == false for i in s: if pred(i): return true - return false + false template anyIt*(s, pred: untyped): bool = - ## Iterates through a container and checks if some item fulfills the - ## predicate. + ## Iterates through a container and checks if at least one item + ## fulfills the predicate. ## ## Unlike the `any proc<#any,openArray[T],proc(T)>`_, ## the predicate needs to be an expression using ## the `it` variable for testing, like: `anyIt("abba", it == 'a')`. ## - ## See also: + ## **See also:** ## * `any proc<#any,openArray[T],proc(T)>`_ ## * `allIt template<#allIt.t,untyped,untyped>`_ ## @@ -747,7 +816,7 @@ template toSeq1(s: not iterator): untyped = i += 1 result else: - var result: seq[OutType] = @[] + var result: seq[OutType]# = @[] for it in s: result.add(it) result @@ -764,7 +833,7 @@ template toSeq2(iter: iterator): untyped = result else: type OutType = typeof(iter2()) - var result: seq[OutType] = @[] + var result: seq[OutType]# = @[] when compiles(iter2()): evalOnceAs(iter4, iter, false) let iter3 = iter4() @@ -827,7 +896,7 @@ template foldl*(sequence, operation: untyped): untyped = ## the sequence of numbers 1, 2 and 3 will be parenthesized as (((1) - 2) - ## 3). ## - ## See also: + ## **See also:** ## * `foldl template<#foldl.t,,,>`_ with a starting parameter ## * `foldr template<#foldr.t,untyped,untyped>`_ ## @@ -870,9 +939,9 @@ template foldl*(sequence, operation, first): untyped = ## ## The `operation` parameter should be an expression which uses the variables ## `a` and `b` for each step of the fold. The `first` parameter is the - ## start value (the first `a`) and therefor defines the type of the result. + ## start value (the first `a`) and therefore defines the type of the result. ## - ## See also: + ## **See also:** ## * `foldr template<#foldr.t,untyped,untyped>`_ ## runnableExamples: @@ -903,7 +972,7 @@ template foldr*(sequence, operation: untyped): untyped = ## the sequence of numbers 1, 2 and 3 will be parenthesized as (1 - (2 - ## (3))). ## - ## See also: + ## **See also:** ## * `foldl template<#foldl.t,untyped,untyped>`_ ## * `foldl template<#foldl.t,,,>`_ with a starting parameter ## @@ -932,7 +1001,7 @@ template foldr*(sequence, operation: untyped): untyped = result template mapIt*(s: typed, op: untyped): untyped = - ## Returns a new sequence with the results of `op` proc applied to every + ## Returns a new sequence with the results of the `op` proc applied to every ## item in the container `s`. ## ## Since the input is not modified you can use it to @@ -944,7 +1013,7 @@ template mapIt*(s: typed, op: untyped): untyped = ## Instead of using `mapIt` and `filterIt`, consider using the `collect` macro ## from the `sugar` module. ## - ## See also: + ## **See also:** ## * `sugar.collect macro<sugar.html#collect.m%2Cuntyped%2Cuntyped>`_ ## * `map proc<#map,openArray[T],proc(T)>`_ ## * `applyIt template<#applyIt.t,untyped,untyped>`_ for the in-place version @@ -955,16 +1024,10 @@ template mapIt*(s: typed, op: untyped): untyped = strings = nums.mapIt($(4 * it)) assert strings == @["4", "8", "12", "16"] - when defined(nimHasTypeof): - type OutType = typeof(( - block: - var it{.inject.}: typeof(items(s), typeOfIter); - op), typeOfProc) - else: - type OutType = typeof(( - block: - var it{.inject.}: typeof(items(s)); - op)) + type OutType = typeof(( + block: + var it{.inject.}: typeof(items(s), typeOfIter); + op), typeOfProc) when OutType is not (proc): # Here, we avoid to create closures in loops. # This avoids https://github.com/nim-lang/Nim/issues/12625 @@ -982,7 +1045,7 @@ template mapIt*(s: typed, op: untyped): untyped = i += 1 result else: - var result: seq[OutType] = @[] + var result: seq[OutType]# = @[] # use `items` to avoid https://github.com/nim-lang/Nim/issues/12639 for it {.inject.} in items(s): result.add(op) @@ -995,11 +1058,7 @@ template mapIt*(s: typed, op: untyped): untyped = # With this fallback, above code can be simplified to: # [1, 2].mapIt((x: int) => it + x) # In this case, `mapIt` is just syntax sugar for `map`. - - when defined(nimHasTypeof): - type InType = typeof(items(s), typeOfIter) - else: - type InType = typeof(items(s)) + type InType = typeof(items(s), typeOfIter) # Use a help proc `f` to create closures for each element in `s` let f = proc (x: InType): OutType = let it {.inject.} = x @@ -1010,10 +1069,10 @@ template applyIt*(varSeq, op: untyped) = ## Convenience template around the mutable `apply` proc to reduce typing. ## ## The template injects the `it` variable which you can use directly in an - ## expression. The expression has to return the same type as the sequence you - ## are mutating. + ## expression. The expression has to return the same type as the elements + ## of the sequence you are mutating. ## - ## See also: + ## **See also:** ## * `apply proc<#apply,openArray[T],proc(T)_2>`_ ## * `mapIt template<#mapIt.t,typed,untyped>`_ ## @@ -1028,27 +1087,31 @@ template applyIt*(varSeq, op: untyped) = template newSeqWith*(len: int, init: untyped): untyped = - ## Creates a new sequence of length `len`, calling `init` to initialize - ## each value of the sequence. - ## - ## Useful for creating "2D" sequences - sequences containing other sequences - ## or to populate fields of the created sequence. + ## Creates a new `seq` of length `len`, calling `init` to initialize + ## each value of the seq. ## + ## Useful for creating "2D" seqs - seqs containing other seqs + ## or to populate fields of the created seq. runnableExamples: - ## Creates a sequence containing 5 bool sequences, each of length of 3. + ## Creates a seq containing 5 bool seqs, each of length of 3. var seq2D = newSeqWith(5, newSeq[bool](3)) assert seq2D.len == 5 assert seq2D[0].len == 3 assert seq2D[4][2] == false - ## Creates a sequence of 20 random numbers from 1 to 10 - import random - var seqRand = newSeqWith(20, rand(10)) - - var result = newSeq[typeof(init)](len) - for i in 0 ..< len: + ## Creates a seq with random numbers + import std/random + var seqRand = newSeqWith(20, rand(1.0)) + assert seqRand[0] != seqRand[1] + type T = typeof(init) + let newLen = len + when supportsCopyMem(T) and declared(newSeqUninit): + var result = newSeqUninit[T](newLen) + else: # TODO: use `newSeqUnsafe` when that's available + var result = newSeq[T](newLen) + for i in 0 ..< newLen: result[i] = init - result + move(result) # refs bug #7295 func mapLitsImpl(constructor: NimNode; op: NimNode; nested: bool; filter = nnkLiterals): NimNode = @@ -1081,7 +1144,7 @@ macro mapLiterals*(constructor, op: untyped; let b = mapLiterals((1.2, (2.3, 3.4), 4.8), int, nested=false) assert a == (1, (2, 3), 4) assert b == (1, (2.3, 3.4), 4) - + let c = mapLiterals((1, (2, 3), 4, (5, 6)), `$`) let d = mapLiterals((1, (2, 3), 4, (5, 6)), `$`, nested=false) assert c == ("1", ("2", "3"), "4", ("5", "6")) |