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proc returnsTuple(): (int, int, int) = (4, 2, 3)
proc main2 =
let (x, _, z) = returnsTuple()
proc main() =
proc foo(): tuple[x, y, z: int] =
return (4, 2, 3)
var (x, _, y) = foo()
doAssert x == 4
doAssert y == 3
var (a, _, _) = foo()
doAssert a == 4
var (aa, _, _) = foo()
doAssert aa == 4
iterator bar(): tuple[x, y, z: int] =
yield (1,2,3)
for x, y, _ in bar():
doAssert x == 1
doAssert y == 2
main()
main2()
block: # nested unpacking
block: # simple let
let (a, (b, c), d) = (1, (2, 3), 4)
doAssert (a, b, c, d) == (1, 2, 3, 4)
let foo = (a, (b, c), d)
let (a2, (b2, c2), d2) = foo
doAssert (a, b, c, d) == (a2, b2, c2, d2)
block: # var and assignment
var (x, (y, z), t) = ('a', (true, @[123]), "abc")
doAssert (x, y, z, t) == ('a', true, @[123], "abc")
(x, (y, z), t) = ('b', (false, @[456]), "def")
doAssert (x, y, z, t) == ('b', false, @[456], "def")
block: # very nested
let (_, (_, (_, (_, (_, a))))) = (1, (2, (3, (4, (5, 6)))))
doAssert a == 6
block: # const
const (a, (b, c), d) = (1, (2, 3), 4)
doAssert (a, b, c, d) == (1, 2, 3, 4)
const foo = (a, (b, c), d)
const (a2, (b2, c2), d2) = foo
doAssert (a, b, c, d) == (a2, b2, c2, d2)
block: # evaluation semantics preserved between literal and not literal
var s: seq[string]
block: # literal
let (a, (b, c), d) = ((s.add("a"); 1), ((s.add("b"); 2), (s.add("c"); 3)), (s.add("d"); 4))
doAssert (a, b, c, d) == (1, 2, 3, 4)
doAssert s == @["a", "b", "c", "d"]
block: # underscore
s = @[]
let (a, (_, c), _) = ((s.add("a"); 1), ((s.add("b"); 2), (s.add("c"); 3)), (s.add("d"); 4))
doAssert (a, c) == (1, 3)
doAssert s == @["a", "b", "c", "d"]
block: # temp
s = @[]
let foo = ((s.add("a"); 1), ((s.add("b"); 2), (s.add("c"); 3)), (s.add("d"); 4))
let (a, (b, c), d) = foo
doAssert (a, b, c, d) == (1, 2, 3, 4)
doAssert s == @["a", "b", "c", "d"]
block: # unary assignment unpacking
var a: int
(a,) = (1,)
doAssert a == 1
block: # type annotations
block: # basic
let (a, b): (int, int) = (1, 2)
doAssert (a, b) == (1, 2)
block: # type inference
let (a, b): (byte, float) = (1, 2)
doAssert (a, b) == (1.byte, 2.0)
block: # type mismatch
doAssert not (compiles do:
let (a, b): (int, string) = (1, 2))
block: # nested
let (a, (b, c)): (int, (int, int)) = (1, (2, 3))
doAssert (a, b, c) == (1, 2, 3)
block: # nested type inference
let (a, (b, c)): (byte, (float, cstring)) = (1, (2, "abc"))
doAssert (a, b, c) == (1.byte, 2.0, cstring"abc")
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