devforms-0.1.1.0: src/ParsedInteger.hs

module ParsedInteger (ParsedInteger, parseWithBounds, parsedToInteger)
where

newtype ParsedInteger = ParsedInteger Integer

parseWithBounds :: Maybe Integer -> Maybe Integer -> Integer -> Either Text ParsedInteger
parseWithBounds (Just lowerBoundInclusive) (Just upperBoundInclusive) n =
    if lowerBoundInclusive <= n && upperBoundInclusive >= n
        then pure $ ParsedInteger n
        else Left "Integer is outside bounds"
parseWithBounds (Just lowerBoundInclusive) Nothing n =
    if lowerBoundInclusive <= n
        then pure $ ParsedInteger n
        else Left "Integer is out of bounds"
parseWithBounds Nothing (Just upperBoundInclusive) n =
    if upperBoundInclusive >= n
        then pure $ ParsedInteger n
        else Left "Integer is out of bounds"
parseWithBounds Nothing Nothing n = Right $ ParsedInteger n

parsedToInteger :: ParsedInteger -> Integer
parsedToInteger (ParsedInteger n) = n