Interpret a Int64 as an unsigned integer, and give its string representation.

toSignedString (fromInt 10)
    --> "10"


toSignedString (fromInt -10)
    --> "-10"

Interpret a Int64 as an unsigned integer, and give its string representation

toUnsignedString (fromInt 10)
    --> "10"


toUnsignedString (fromInt -10)
    --> "18446744073709551606"

Parse a signed Int64 from its string representation

fromSignedString "10"
    --> Just (Int64 { higher = 0, lower = 10 })


fromSignedString "-10"
    --> Just (Int64 { higher = -1, lower = -10 })


fromSignedString "not-a-number"
    --> Nothing


fromSignedString "9223372036854775807"
    --> Just (Int64 { higher = 2147483647, lower = -1 })


fromSignedString "-9223372036854775808"
    --> Just (Int64 { higher = -2147483648, lower = 0 })


fromSignedString "-9223372036854775809"
    --> Nothing

Parse an unsigned Int64 from its string representation

fromUnsignedString "10"
    --> Just (Int64 { higher = 0, lower = 10 })


fromUnsignedString "-10"
    --> Nothing


fromUnsignedString "not-a-number"
    --> Nothing


fromUnsignedString "9223372036854775807"
    --> Just (Int64 { higher = 2147483647, lower = -1 })


fromUnsignedString "18446744073709551615"
    --> Just (Int64 { higher = -1, lower = -1 })


fromUnsignedString "18446744073709551616"
    --> Nothing