whenNext :: Char -> a -> Parser a
whenNext c a = do
    mbChar <- AP.peekChar
    if mbChar == Just c
        then return a
        else fail "whenNext"

-- 4.3.4. Consume a string token
whenNext :: Char -> a -> Parser a
whenNext c a = do
    mbChar <- AP.peekChar
    if mbChar == Just c
        then return a
        else fail "whenNext"

-- 4.3.4. Consume a string token
whenNext c a = do
    mbChar <- AP.peekChar
    if mbChar == Just c
        then return a
        else fail "whenNext"

-- 4.3.4. Consume a string token