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template accept(x) =
static: assert(compiles(x))
template reject(x) =
static: assert(not compiles(x))
type
Kind = enum k1 = 0, k2 = 33, k3 = 84, k4 = 278, k5 = 1000 # Holed enum work! #No they don't..
KindObj = object
case kind: Kind
of k1, k2..k3: i32: int32
of k4: f32: float32
else: str: string
IntObj = object
case kind: uint8
of low(uint8) .. 127: bad: string
of 128'u8: neutral: string
of 129 .. high(uint8): good: string
OtherKind = enum ok1, ok2, ok3, ok4, ok5
NestedKindObj = object
case kind: Kind
of k3, k5: discard
of k2: str: string
of k1, k4:
case otherKind: OtherKind
of ok1, ok2..ok3: i32: int32
of ok4: f32: float32
else: nestedStr: string
let kind = k4 # actual value should have no impact on the analysis.
accept: # Mimics the structure of the type. The optimial case.
case kind
of k1, k2, k3: discard KindObj(kind: kind, i32: 1)
of k4: discard KindObj(kind: kind, f32: 2.0)
else: discard KindObj(kind: kind, str: "3")
accept: # Specifying the else explicitly is fine too.
case kind
of k1, k2, k3: discard KindObj(kind: kind, i32: 1)
of k4: discard KindObj(kind: kind, f32: 2.0)
of k5: discard KindObj(kind: kind, str: "3")
accept:
case kind
of k1..k3, k5: discard
else: discard KindObj(kind: kind, f32: 2.0)
accept:
case kind
of k4, k5: discard
else: discard KindObj(kind: kind, i32: 1)
accept: # elif branches are ignored
case kind
of k1, k2, k3: discard KindObj(kind: kind, i32: 1)
of k4: discard KindObj(kind: kind, f32: 2.0)
elif kind in {k1..k5}: discard
else: discard KindObj(kind: kind, str: "3")
reject: # k4 conflicts with i32
case kind
of k1, k2, k3, k4: discard KindObj(kind: kind, i32: 1)
else: discard KindObj(kind: kind, str: "3")
reject: # k4 is not caught, conflicts with str in the else branch
case kind
of k1, k2, k3: discard KindObj(kind: kind, i32: 1)
else: discard KindObj(kind: kind, str: "3")
reject: # elif branches are ignored
case kind
of k1, k2, k3: discard KindObj(kind: kind, i32: 1)
elif kind == k4: discard
else: discard KindObj(kind: kind, str: "3")
let intKind = 29'u8
accept:
case intKind
of low(uint8) .. 127: discard IntObj(kind: intKind, bad: "bad")
of 128'u8: discard IntObj(kind: intKind, neutral: "neutral")
of 129 .. high(uint8): discard IntObj(kind: intKind, good: "good")
reject: # 0 leaks to else
case intKind
of low(uint8) .. 127: discard IntObj(kind: intKind, bad: "bad")
of 129 .. high(uint8): discard IntObj(kind: intKind, good: "good")
accept:
case intKind
of low(uint8) .. 127: discard IntObj(kind: intKind, bad: "bad")
of 128'u8: discard IntObj(kind: intKind, neutral: "neutral")
of 139'u8, 140 .. high(uint8), 129'u8 .. 138'u8: discard IntObj(kind: intKind, good: "good")
accept:
case kind
of {k1, k2}, [k3]: discard KindObj(kind: kind, i32: 1)
of k4: discard KindObj(kind: kind, f32: 2.0)
else: discard KindObj(kind: kind, str: "3")
reject:
case kind
of {k1, k2, k3}, [k4]: discard KindObj(kind: kind, i32: 1)
else: discard KindObj(kind: kind, str: "3")
accept:
case kind
of k3, k5: discard NestedKindObj(kind: kind)
of k2: discard NestedKindObj(kind: kind, str: "not nested")
of k1, k4:
let otherKind = ok5
case otherKind
of ok1..ok3: discard NestedKindObj(kind: kind, otherKind: otherKind, i32: 3)
of ok4: discard NestedKindObj(kind: kind, otherKind: otherKind, f32: 5.0)
else: discard NestedKindObj(kind: kind, otherKind: otherKind,
nestedStr: "nested")
reject:
case kind
of k3, k5: discard NestedKindObj(kind: kind)
of k2: discard NestedKindObj(kind: kind, str: "not nested")
of k1, k4:
let otherKind = ok5
case otherKind
of ok1..ok3: discard NestedKindObj(kind: kind, otherKind: otherKind, i32: 3)
else: discard NestedKindObj(kind: kind, otherKind: otherKind,
nestedStr: "nested")
var varkind = k4
reject: # not immutable.
case varkind
of k1, k2, k3: discard KindObj(varkind: kind, i32: 1)
of k4: discard KindObj(varkind: kind, f32: 2.0)
else: discard KindObj(varkind: kind, str: "3")
accept:
proc kindProc(kind: Kind): KindObj =
case kind:
of k1: result = KindObj(kind: kind, i32: 1)
else: discard
reject:
proc varKindProc(kind: var Kind): KindObj =
case kind:
of k1: result = KindObj(kind: kind, i32: 1)
else: discard
type
Kind3 = enum
A, B, C, E
OkRange = range[B..C]
NotOkRange = range[B..E]
CaseObject = object
case kind: Kind3
of B, C:
field: int
else: discard
accept:
let rtDiscriminator: OkRange = B
discard CaseObject(kind: rtDiscriminator, field: 1)
accept:
let rtDiscriminator = B
discard CaseObject(kind: OkRange(rtDiscriminator), field: 1)
accept:
const rtDiscriminator: NotOkRange = B
discard CaseObject(kind: rtDiscriminator, field: 1)
accept:
discard CaseObject(kind: NotOkRange(B), field: 1)
reject:
let rtDiscriminator: NotOkRange = B
discard CaseObject(kind: rtDiscriminator, field: 1)
reject:
let rtDiscriminator = B
discard CaseObject(kind: NotOkRange(rtDiscriminator), field: 1)
reject:
type Obj = object
case x: int
of 0 .. 1000:
field: int
else:
discard
let x: range[0..15] = 1
let o = Obj(x: x, field: 1)
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