diff options
Diffstat (limited to 'lib/system.nim')
| -rw-r--r-- | lib/system.nim | 237 |
1 files changed, 130 insertions, 107 deletions
diff --git a/lib/system.nim b/lib/system.nim index dc3152faf..92c5e009f 100644 --- a/lib/system.nim +++ b/lib/system.nim @@ -275,7 +275,7 @@ proc low*[T](x: T): T {.magic: "Low", noSideEffect.} proc low*[I, T](x: typeDesc[array[I, T]]): I {.magic: "Low", noSideEffect.} proc low*(x: cstring): int {.magic: "Low", noSideEffect.} proc low*(x: string): int {.magic: "Low", noSideEffect.} -## returns the lowest possible index of an array, a sequence, a string or + ## returns the lowest possible index of an array, a sequence, a string or ## the lowest possible value of an ordinal value `x`. As a special ## semantic rule, `x` may also be a type identifier. ## @@ -285,6 +285,13 @@ proc low*(x: string): int {.magic: "Low", noSideEffect.} ## low(2) #=> -9223372036854775808 ## low(int) #=> -9223372036854775808 +proc shallowCopy*[T](x: var T, y: T) {.noSideEffect, magic: "ShallowCopy".} + ## use this instead of `=` for a `shallow copy`:idx:. The shallow copy + ## only changes the semantics for sequences and strings (and types which + ## contain those). Be careful with the changed semantics though! There + ## is a reason why the default assignment does a deep copy of sequences + ## and strings. + when defined(nimArrIdx): # :array|openarray|string|seq|cstring|tuple proc `[]`*[I: Ordinal;T](a: T; i: I): T {. @@ -292,15 +299,21 @@ when defined(nimArrIdx): proc `[]=`*[I: Ordinal;T,S](a: T; i: I; x: S) {.noSideEffect, magic: "ArrPut".} proc `=`*[T](dest: var T; src: T) {.noSideEffect, magic: "Asgn".} + when defined(nimNewRuntime): + proc `=destroy`*[T](x: var T) {.inline, magic: "Asgn".} = + ## generic `destructor`:idx: implementation that can be overriden. + discard + proc `=sink`*[T](x: var T; y: T) {.inline, magic: "Asgn".} = + ## generic `sink`:idx: implementation that can be overriden. + shallowCopy(x, y) type - Slice*[T] = object ## builtin slice type - a*, b*: T ## the bounds + HSlice*[T, U] = object ## "heterogenous" slice type + a*: T ## the lower bound (inclusive) + b*: U ## the upper bound (inclusive) + Slice*[T] = HSlice[T, T] ## an alias for ``HSlice[T, T]`` -when defined(nimalias): - {.deprecated: [TSlice: Slice].} - -proc `..`*[T](a, b: T): Slice[T] {.noSideEffect, inline, magic: "DotDot".} = +proc `..`*[T, U](a: T, b: U): HSlice[T, U] {.noSideEffect, inline, magic: "DotDot".} = ## `slice`:idx: operator that constructs an interval ``[a, b]``, both `a` ## and `b` are inclusive. Slices can also be used in the set constructor ## and in ordinal case statements, but then they are special-cased by the @@ -308,7 +321,7 @@ proc `..`*[T](a, b: T): Slice[T] {.noSideEffect, inline, magic: "DotDot".} = result.a = a result.b = b -proc `..`*[T](b: T): Slice[T] {.noSideEffect, inline, magic: "DotDot".} = +proc `..`*[T](b: T): HSlice[int, T] {.noSideEffect, inline, magic: "DotDot".} = ## `slice`:idx: operator that constructs an interval ``[default(T), b]`` result.b = b @@ -638,13 +651,17 @@ proc sizeof*[T](x: T): int {.magic: "SizeOf", noSideEffect.} when defined(nimtypedescfixed): proc sizeof*(x: typedesc): int {.magic: "SizeOf", noSideEffect.} -proc `<`*[T](x: Ordinal[T]): T {.magic: "UnaryLt", noSideEffect.} +proc `<`*[T](x: Ordinal[T]): T {.magic: "UnaryLt", noSideEffect, deprecated.} ## unary ``<`` that can be used for nice looking excluding ranges: ## ## .. code-block:: nim ## for i in 0 .. <10: echo i #=> 0 1 2 3 4 5 6 7 8 9 ## ## Semantically this is the same as ``pred``. + ## + ## **Deprecated since version 0.18.0**. For the common excluding range + ## write ``0 ..< 10`` instead of ``0 .. < 10`` (look at the spacing). + ## For ``<x`` write ``pred(x)``. proc succ*[T](x: Ordinal[T], y = 1): T {.magic: "Succ", noSideEffect.} ## returns the ``y``-th successor of the value ``x``. ``T`` has to be @@ -1150,7 +1167,7 @@ proc contains*[T](x: set[T], y: T): bool {.magic: "InSet", noSideEffect.} ## is achieved by reversing the parameters for ``contains``; ``in`` then ## passes its arguments in reverse order. -proc contains*[T](s: Slice[T], value: T): bool {.noSideEffect, inline.} = +proc contains*[U, V, W](s: HSlice[U, V], value: W): bool {.noSideEffect, inline.} = ## Checks if `value` is within the range of `s`; returns true iff ## `value >= s.a and value <= s.b` ## @@ -1429,7 +1446,8 @@ when defined(nimdoc): ## <#GC_fullCollect>`_. ## ## The proc ``quit(QuitSuccess)`` is called implicitly when your nim - ## program finishes without incident. A raised unhandled exception is + ## program finishes without incident for platforms where this is the + ## expected behavior. A raised unhandled exception is ## equivalent to calling ``quit(QuitFailure)``. ## ## Note that this is a *runtime* call and using ``quit`` inside a macro won't @@ -1444,7 +1462,7 @@ elif defined(genode): header: "<base/sleep.h>".} elif defined(nodejs): - proc quit*(errorcode: int = QuitSuccess) {.magic: "Exit", + proc quit*(errorcode: int = QuitSuccess) {.magic: "Exit", importc: "process.exit", noreturn.} else: @@ -1480,13 +1498,6 @@ proc add *[T](x: var seq[T], y: openArray[T]) {.noSideEffect.} = setLen(x, xl + y.len) for i in 0..high(y): x[xl+i] = y[i] -proc shallowCopy*[T](x: var T, y: T) {.noSideEffect, magic: "ShallowCopy".} - ## use this instead of `=` for a `shallow copy`:idx:. The shallow copy - ## only changes the semantics for sequences and strings (and types which - ## contain those). Be careful with the changed semantics though! There - ## is a reason why the default assignment does a deep copy of sequences - ## and strings. - proc del*[T](x: var seq[T], i: Natural) {.noSideEffect.} = ## deletes the item at index `i` by putting ``x[high(x)]`` into position `i`. ## This is an O(1) operation. @@ -1875,7 +1886,7 @@ proc `$` *(x: float): string {.magic: "FloatToStr", noSideEffect.} proc `$` *(x: bool): string {.magic: "BoolToStr", noSideEffect.} ## The stringify operator for a boolean argument. Returns `x` ## converted to the string "false" or "true". - +# proc `$` *(x: char): string {.magic: "CharToStr", noSideEffect.} ## The stringify operator for a character argument. Returns `x` ## converted to a string. @@ -2065,6 +2076,9 @@ proc max*[T](x, y: T): T = if y <= x: x else: y {.pop.} +proc high*(T: typedesc[SomeReal]): T = Inf +proc low*(T: typedesc[SomeReal]): T = NegInf + proc clamp*[T](x, a, b: T): T = ## limits the value ``x`` within the interval [a, b] ## @@ -2075,7 +2089,7 @@ proc clamp*[T](x, a, b: T): T = if x > b: return b return x -proc len*[T: Ordinal](x: Slice[T]): int {.noSideEffect, inline.} = +proc len*[U: Ordinal; V: Ordinal](x: HSlice[U, V]): int {.noSideEffect, inline.} = ## length of ordinal slice, when x.b < x.a returns zero length ## ## .. code-block:: Nim @@ -2143,7 +2157,7 @@ iterator items*(E: typedesc[enum]): E = for v in low(E)..high(E): yield v -iterator items*[T](s: Slice[T]): T = +iterator items*[T](s: HSlice[T, T]): T = ## iterates over the slice `s`, yielding each value between `s.a` and `s.b` ## (inclusively). for x in s.a..s.b: @@ -2437,20 +2451,28 @@ proc `$`*[T: tuple|object](x: T): string = result.add("...") result.add(")") -proc collectionToString[T: set | seq](x: T, b, e: string): string = - when x is seq: - if x.isNil: return "nil" - result = b +proc collectionToString[T](x: T, prefix, separator, suffix: string): string = + result = prefix var firstElement = true for value in items(x): - if not firstElement: result.add(", ") + if firstElement: + firstElement = false + else: + result.add(separator) + when compiles(value.isNil): - if value.isNil: result.add "nil" - else: result.add($value) + # this branch should not be necessary + if value.isNil: + result.add "nil" + else: + result.add($value) + # prevent temporary string allocation + elif compiles(result.add(value)): + result.add(value) else: result.add($value) - firstElement = false - result.add(e) + + result.add(suffix) proc `$`*[T](x: set[T]): string = ## generic ``$`` operator for sets that is lifted from the components @@ -2458,7 +2480,7 @@ proc `$`*[T](x: set[T]): string = ## ## .. code-block:: nim ## ${23, 45} == "{23, 45}" - collectionToString(x, "{", "}") + collectionToString(x, "{", ", ", "}") proc `$`*[T](x: seq[T]): string = ## generic ``$`` operator for seqs that is lifted from the components @@ -2466,13 +2488,10 @@ proc `$`*[T](x: seq[T]): string = ## ## .. code-block:: nim ## $(@[23, 45]) == "@[23, 45]" - collectionToString(x, "@[", "]") - -when false: - # causes bootstrapping to fail as we use array of chars and cstring should - # match better ... - proc `$`*[T, IDX](x: array[IDX, T]): string = - collectionToString(x, "[", "]") + if x.isNil: + "nil" + else: + collectionToString(x, "@[", ", ", "]") # ----------------- GC interface --------------------------------------------- @@ -2816,7 +2835,7 @@ when not defined(JS): #and not defined(nimscript): fmRead, ## Open the file for read access only. fmWrite, ## Open the file for write access only. ## If the file does not exist, it will be - ## created. + ## created. Existing files will be cleared! fmReadWrite, ## Open the file for read and write access. ## If the file does not exist, it will be ## created. Existing files will be cleared! @@ -2872,7 +2891,7 @@ when not defined(JS): #and not defined(nimscript): importc: when defined(bcc): "setmode" else: "_setmode", header: "<io.h>".} var - O_BINARY {.importc: "O_BINARY", nodecl.}: cint + O_BINARY {.importc: "_O_BINARY", header:"<fcntl.h>".}: cint # we use binary mode on Windows: c_setmode(c_fileno(stdin), O_BINARY) @@ -3329,6 +3348,10 @@ elif defined(JS): include "system/sysio" +proc `$`*[T, IDX](x: array[IDX, T]): string = + ## generic ``$`` operator for arrays that is lifted from the components + collectionToString(x, "[", ", ", "]") + proc quit*(errormsg: string, errorcode = QuitFailure) {.noReturn.} = ## a shorthand for ``echo(errormsg); quit(errorcode)``. echo(errormsg) @@ -3393,6 +3416,29 @@ proc `/`*(x, y: int): float {.inline, noSideEffect.} = ## integer division that results in a float. result = toFloat(x) / toFloat(y) +type + BackwardsIndex* = distinct int ## type that is constructed by ``^`` for + ## reversed array accesses. + +template `^`*(x: int): BackwardsIndex = BackwardsIndex(x) + ## builtin `roof`:idx: operator that can be used for convenient array access. + ## ``a[^x]`` is a shortcut for ``a[a.len-x]``. + +template `..^`*(a, b: untyped): untyped = + ## a shortcut for '.. ^' to avoid the common gotcha that a space between + ## '..' and '^' is required. + a .. ^b + +template `..<`*(a, b: untyped): untyped = + ## a shortcut for 'a..pred(b)'. + a .. pred(b) + +iterator `..<`*[S,T](a: S, b: T): T = + var i = T(a) + while i < b: + yield i + inc i + template spliceImpl(s, a, L, b: untyped): untyped = # make room for additional elements or cut: var shift = b.len - max(0,L) # ignore negative slice size @@ -3406,19 +3452,22 @@ template spliceImpl(s, a, L, b: untyped): untyped = # cut down: setLen(s, newLen) # fill the hole: - for i in 0 .. <b.len: s[a+i] = b[i] + for i in 0 ..< b.len: s[a+i] = b[i] + +template `^^`(s, i: untyped): untyped = + (when i is BackwardsIndex: s.len - int(i) else: int(i)) when hasAlloc or defined(nimscript): - proc `[]`*(s: string, x: Slice[int]): string {.inline.} = + proc `[]`*[T, U](s: string, x: HSlice[T, U]): string {.inline.} = ## slice operation for strings. ## returns the inclusive range [s[x.a], s[x.b]]: ## ## .. code-block:: nim ## var s = "abcdef" ## assert s[1..3] == "bcd" - result = s.substr(x.a, x.b) + result = s.substr(s ^^ x.a, s ^^ x.b) - proc `[]=`*(s: var string, x: Slice[int], b: string) = + proc `[]=`*[T, U](s: var string, x: HSlice[T, U], b: string) = ## slice assignment for strings. If ## ``b.len`` is not exactly the number of elements that are referred to ## by `x`, a `splice`:idx: is performed: @@ -3427,75 +3476,74 @@ when hasAlloc or defined(nimscript): ## var s = "abcdef" ## s[1 .. ^2] = "xyz" ## assert s == "axyzf" - var a = x.a - var L = x.b - a + 1 + var a = s ^^ x.a + var L = (s ^^ x.b) - a + 1 if L == b.len: - for i in 0 .. <L: s[i+a] = b[i] + for i in 0..<L: s[i+a] = b[i] else: spliceImpl(s, a, L, b) -proc `[]`*[Idx, T](a: array[Idx, T], x: Slice[int]): seq[T] = +proc `[]`*[Idx, T, U, V](a: array[Idx, T], x: HSlice[U, V]): seq[T] = ## slice operation for arrays. ## returns the inclusive range [a[x.a], a[x.b]]: ## ## .. code-block:: nim ## var a = [1,2,3,4] ## assert a[0..2] == @[1,2,3] - when low(a) < 0: - {.error: "Slicing for arrays with negative indices is unsupported.".} - var L = x.b - x.a + 1 + let xa = a ^^ x.a + let L = (a ^^ x.b) - xa + 1 result = newSeq[T](L) - for i in 0.. <L: result[i] = a[i + x.a] - -proc `[]=`*[Idx, T](a: var array[Idx, T], x: Slice[int], b: openArray[T]) = - ## slice assignment for arrays. - when low(a) < 0: - {.error: "Slicing for arrays with negative indices is unsupported.".} - var L = x.b - x.a + 1 - if L == b.len: - for i in 0 .. <L: a[i+x.a] = b[i] - else: - sysFatal(RangeError, "different lengths for slice assignment") - -proc `[]`*[Idx, T](a: array[Idx, T], x: Slice[Idx]): seq[T] = - ## slice operation for arrays. - var L = ord(x.b) - ord(x.a) + 1 - newSeq(result, L) - for i in 0.. <L: - result[i] = a[Idx(ord(x.a) + i)] + for i in 0..<L: result[i] = a[Idx(i + xa + int low(a))] -proc `[]=`*[Idx, T](a: var array[Idx, T], x: Slice[Idx], b: openArray[T]) = +proc `[]=`*[Idx, T, U, V](a: var array[Idx, T], x: HSlice[U, V], b: openArray[T]) = ## slice assignment for arrays. - var L = ord(x.b) - ord(x.a) + 1 + let xa = a ^^ x.a + let L = (a ^^ x.b) - xa + 1 if L == b.len: - for i in 0 .. <L: - a[Idx(ord(x.a) + i)] = b[i] + for i in 0..<L: a[Idx(i + xa + int low(a))] = b[i] else: sysFatal(RangeError, "different lengths for slice assignment") -proc `[]`*[T](s: seq[T], x: Slice[int]): seq[T] = +proc `[]`*[T, U, V](s: openArray[T], x: HSlice[U, V]): seq[T] = ## slice operation for sequences. ## returns the inclusive range [s[x.a], s[x.b]]: ## ## .. code-block:: nim ## var s = @[1,2,3,4] ## assert s[0..2] == @[1,2,3] - var a = x.a - var L = x.b - a + 1 + let a = s ^^ x.a + let L = (s ^^ x.b) - a + 1 newSeq(result, L) - for i in 0.. <L: result[i] = s[i + a] + for i in 0 ..< L: result[i] = s[i + a] -proc `[]=`*[T](s: var seq[T], x: Slice[int], b: openArray[T]) = +proc `[]=`*[T, U, V](s: var seq[T], x: HSlice[U, V], b: openArray[T]) = ## slice assignment for sequences. If ## ``b.len`` is not exactly the number of elements that are referred to ## by `x`, a `splice`:idx: is performed. - var a = x.a - var L = x.b - a + 1 + let a = s ^^ x.a + let L = (s ^^ x.b) - a + 1 if L == b.len: - for i in 0 .. <L: s[i+a] = b[i] + for i in 0 ..< L: s[i+a] = b[i] else: spliceImpl(s, a, L, b) +proc `[]`*[T](s: openArray[T]; i: BackwardsIndex): T {.inline.} = s[s.len - int(i)] +proc `[]`*[Idx, T](a: array[Idx, T]; i: BackwardsIndex): T {.inline.} = + a[Idx(a.len - int(i) + int low(a))] +proc `[]`*(s: string; i: BackwardsIndex): char {.inline.} = s[s.len - int(i)] + +proc `[]`*[T](s: var openArray[T]; i: BackwardsIndex): var T {.inline.} = + s[s.len - int(i)] +proc `[]`*[Idx, T](a: var array[Idx, T]; i: BackwardsIndex): var T {.inline.} = + a[Idx(a.len - int(i) + int low(a))] + +proc `[]=`*[T](s: var openArray[T]; i: BackwardsIndex; x: T) {.inline.} = + s[s.len - int(i)] = x +proc `[]=`*[Idx, T](a: var array[Idx, T]; i: BackwardsIndex; x: T) {.inline.} = + a[Idx(a.len - int(i) + int low(a))] = x +proc `[]=`*(s: var string; i: BackwardsIndex; x: char) {.inline.} = + s[s.len - int(i)] = x + proc slurp*(filename: string): string {.magic: "Slurp".} ## This is an alias for `staticRead <#staticRead>`_. @@ -3836,31 +3884,6 @@ proc procCall*(x: untyped) {.magic: "ProcCall", compileTime.} = ## procCall someMethod(a, b) discard -proc `^`*[T](x: int; y: openArray[T]): int {.noSideEffect, magic: "Roof".} -proc `^`*(x: int): int {.noSideEffect, magic: "Roof".} = - ## builtin `roof`:idx: operator that can be used for convenient array access. - ## ``a[^x]`` is rewritten to ``a[a.len-x]``. However currently the ``a`` - ## expression must not have side effects for this to compile. Note that since - ## this is a builtin, it automatically works for all kinds of - ## overloaded ``[]`` or ``[]=`` accessors. - discard - -template `..^`*(a, b: untyped): untyped = - ## a shortcut for '.. ^' to avoid the common gotcha that a space between - ## '..' and '^' is required. - a .. ^b - -template `..<`*(a, b: untyped): untyped {.dirty.} = - ## a shortcut for '.. <' to avoid the common gotcha that a space between - ## '..' and '<' is required. - a .. <b - -iterator `..<`*[S,T](a: S, b: T): T = - var i = T(a) - while i < b: - yield i - inc i - proc xlen*(x: string): int {.magic: "XLenStr", noSideEffect.} = discard proc xlen*[T](x: seq[T]): int {.magic: "XLenSeq", noSideEffect.} = ## returns the length of a sequence or a string without testing for 'nil'. |