:sig
function u8(value : as string, opt : dval = {}) u8

:params
value : scalar value or text to convert
opt : options map with `fallback` and `base`

:returns
An unsigned 8-bit integer, or `opt.fallback`.

:content
`u8()` parses text in the range 0 through 255. Invalid, negative, or out-of-range text returns `opt.fallback`. The default fallback is `0`.

:example capy render
print(u8("ff", base: 16), "\n")

:see-group
constructors
