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{.experimental: "openSym".}
block: # issue #22605, normal call syntax
const error = "bad"
template valueOr(self: int, def: untyped): untyped =
case false
of true: ""
of false:
template error: untyped {.used, inject.} = "good"
def
proc g(T: type): string =
let x = valueOr 123:
return $error
"ok"
doAssert g(int) == "good"
proc g2(T: type): string =
bind error # use the bad version on purpose
let x = valueOr 123:
return $error
"ok"
doAssert g2(int) == "bad"
block: # issue #22605, method call syntax
const error = "bad"
template valueOr(self: int, def: untyped): untyped =
case false
of true: ""
of false:
template error: untyped {.used, inject.} = "good"
def
proc g(T: type): string =
let x = 123.valueOr:
return $error
"ok"
doAssert g(int) == "good"
proc g2(T: type): string =
bind error # use the bad version on purpose
let x = 123.valueOr:
return $error
"ok"
doAssert g2(int) == "bad"
block: # issue #22605, original complex example
type Xxx = enum
error
value
type
Result[T, E] = object
when T is void:
when E is void:
oResultPrivate*: bool
else:
case oResultPrivate*: bool
of false:
eResultPrivate*: E
of true:
discard
else:
when E is void:
case oResultPrivate*: bool
of false:
discard
of true:
vResultPrivate*: T
else:
case oResultPrivate*: bool
of false:
eResultPrivate*: E
of true:
vResultPrivate*: T
template valueOr[T: not void, E](self: Result[T, E], def: untyped): untyped =
let s = (self) # TODO avoid copy
case s.oResultPrivate
of true:
s.vResultPrivate
of false:
when E isnot void:
template error: untyped {.used, inject.} = s.eResultPrivate
def
proc f(): Result[int, cstring] =
Result[int, cstring](oResultPrivate: false, eResultPrivate: "f")
proc g(T: type): string =
let x = f().valueOr:
return $error
"ok"
doAssert g(int) == "f"
proc g2(T: type): string =
bind error # use the bad version on purpose
let x = f().valueOr:
return $error
"ok"
doAssert g2(int) == "error"
block: # issue #23865
type Xxx = enum
error
value
type
Result[T, E] = object
when T is void:
when E is void:
oResultPrivate: bool
else:
case oResultPrivate: bool
of false:
eResultPrivate: E
of true:
discard
else:
when E is void:
case oResultPrivate: bool
of false:
discard
of true:
vResultPrivate: T
else:
case oResultPrivate: bool
of false:
eResultPrivate: E
of true:
vResultPrivate: T
func error[T, E](self: Result[T, E]): E =
## Fetch error of result if set, or raise Defect
case self.oResultPrivate
of true:
when T isnot void:
raiseResultDefect("Trying to access error when value is set", self.vResultPrivate)
else:
raiseResultDefect("Trying to access error when value is set")
of false:
when E isnot void:
self.eResultPrivate
template valueOr[T: not void, E](self: Result[T, E], def: untyped): untyped =
let s = (self) # TODO avoid copy
case s.oResultPrivate
of true:
s.vResultPrivate
of false:
when E isnot void:
template error: untyped {.used, inject.} = s.eResultPrivate
def
proc f(): Result[int, cstring] =
Result[int, cstring](oResultPrivate: false, eResultPrivate: "f")
proc g(T: type): string =
let x = f().valueOr:
return $error
"ok"
doAssert g(int) == "f"
import sequtils
block: # issue #12283
var b = 5
type Foo[T] = object
h, w: int
proc bar[T](foos: seq[Foo[T]]): T =
let w = foldl(foos, a + b.w, 0)
w
let foos = @[Foo[int](h: 3, w: 5), Foo[int](h: 4, w: 6)]
doAssert bar(foos) == 11
|
