elcritch / variant

Variant type and type matching for Nim

variant

Variant type and type matching for Nim

import variant

var v = newVariant(5)
assert v.ofType(int)
assert v.get(int) == 5

v = newVariant(3.0)
assert v.ofType(float)
assert v.get(float) == 3.0

v = newVariant(@[1, 2, 3])
assert v.ofType(seq[int])
assert v.get(seq[int])[1] == 2

Matching:

var v = newVariant(@[1, 2, 3])
assert v.ofType(seq[int])
variantMatch case v as u
of int:
    echo "u is int: ", u
of seq[int]:
    echo "u is seq[int]: ", u
else:
    echo "dont know what v is"

Will output:

u is seq[int]: @[1, 2, 3]