diff options
Diffstat (limited to 'lib/pure/options.nim')
| -rw-r--r-- | lib/pure/options.nim | 41 |
1 files changed, 25 insertions, 16 deletions
diff --git a/lib/pure/options.nim b/lib/pure/options.nim index 63e3598f0..b34ff72c0 100644 --- a/lib/pure/options.nim +++ b/lib/pure/options.nim @@ -53,7 +53,7 @@ Pattern matching supports pattern matching on `Option`s, with the `Some(<pattern>)` and `None()` patterns. -.. code-block:: nim + ```nim {.experimental: "caseStmtMacros".} import fusion/matching @@ -65,15 +65,24 @@ supports pattern matching on `Option`s, with the `Some(<pattern>)` and assert false assertMatch(some(some(none(int))), Some(Some(None()))) + ``` ]## # xxx pending https://github.com/timotheecour/Nim/issues/376 use `runnableExamples` and `whichModule` +when defined(nimHasEffectsOf): + {.experimental: "strictEffects".} +else: + {.pragma: effectsOf.} import std/typetraits +when defined(nimPreviewSlimSystem): + import std/assertions + + when (NimMajor, NimMinor) >= (1, 1): type - SomePointer = ref | ptr | pointer | proc + SomePointer = ref | ptr | pointer | proc | iterator {.closure.} else: type SomePointer = ref | ptr | pointer @@ -81,7 +90,7 @@ else: type Option*[T] = object ## An optional type that may or may not contain a value of type `T`. - ## When `T` is a a pointer type (`ptr`, `pointer`, `ref` or `proc`), + ## When `T` is a a pointer type (`ptr`, `pointer`, `ref`, `proc` or `iterator {.closure.}`), ## `none(T)` is represented as `nil`. when T is SomePointer: val: T @@ -92,7 +101,7 @@ type UnpackDefect* = object of Defect UnpackError* {.deprecated: "See corresponding Defect".} = UnpackDefect -proc option*[T](val: T): Option[T] {.inline.} = +proc option*[T](val: sink T): Option[T] {.inline.} = ## Can be used to convert a pointer type (`ptr`, `pointer`, `ref` or `proc`) to an option type. ## It converts `nil` to `none(T)`. When `T` is no pointer type, this is equivalent to `some(val)`. ## @@ -108,11 +117,12 @@ proc option*[T](val: T): Option[T] {.inline.} = assert option[Foo](nil).isNone assert option(42).isSome - result.val = val - when T isnot SomePointer: - result.has = true + when T is SomePointer: + result = Option[T](val: val) + else: + result = Option[T](has: true, val: val) -proc some*[T](val: T): Option[T] {.inline.} = +proc some*[T](val: sink T): Option[T] {.inline.} = ## Returns an `Option` that has the value `val`. ## ## **See also:** @@ -127,10 +137,9 @@ proc some*[T](val: T): Option[T] {.inline.} = when T is SomePointer: assert not val.isNil - result.val = val + result = Option[T](val: val) else: - result.has = true - result.val = val + result = Option[T](has: true, val: val) proc none*(T: typedesc): Option[T] {.inline.} = ## Returns an `Option` for this type that has no value. @@ -143,7 +152,7 @@ proc none*(T: typedesc): Option[T] {.inline.} = assert none(int).isNone # the default is the none type - discard + result = Option[T]() proc none*[T]: Option[T] {.inline.} = ## Alias for `none(T) <#none,typedesc>`_. @@ -222,7 +231,7 @@ proc get*[T](self: var Option[T]): var T {.inline.} = raise newException(UnpackDefect, "Can't obtain a value from a `none`") return self.val -proc map*[T](self: Option[T], callback: proc (input: T)) {.inline.} = +proc map*[T](self: Option[T], callback: proc (input: T)) {.inline, effectsOf: callback.} = ## Applies a `callback` function to the value of the `Option`, if it has one. ## ## **See also:** @@ -241,7 +250,7 @@ proc map*[T](self: Option[T], callback: proc (input: T)) {.inline.} = if self.isSome: callback(self.val) -proc map*[T, R](self: Option[T], callback: proc (input: T): R): Option[R] {.inline.} = +proc map*[T, R](self: Option[T], callback: proc (input: T): R): Option[R] {.inline, effectsOf: callback.} = ## Applies a `callback` function to the value of the `Option` and returns an ## `Option` containing the new value. ## @@ -278,7 +287,7 @@ proc flatten*[T](self: Option[Option[T]]): Option[T] {.inline.} = none(T) proc flatMap*[T, R](self: Option[T], - callback: proc (input: T): Option[R]): Option[R] {.inline.} = + callback: proc (input: T): Option[R]): Option[R] {.inline, effectsOf: callback.} = ## Applies a `callback` function to the value of the `Option` and returns the new value. ## ## If the `Option` has no value, `none(R)` will be returned. @@ -303,7 +312,7 @@ proc flatMap*[T, R](self: Option[T], map(self, callback).flatten() -proc filter*[T](self: Option[T], callback: proc (input: T): bool): Option[T] {.inline.} = +proc filter*[T](self: Option[T], callback: proc (input: T): bool): Option[T] {.inline, effectsOf: callback.} = ## Applies a `callback` to the value of the `Option`. ## ## If the `callback` returns `true`, the option is returned as `some`. |