Function is_sarcasm 

pub fn is_sarcasm(input: &str) -> IsSarcasm

Determines if input is SaRcAsM and what the case of the first letter is.

All non-alphanumeric characters will be ignored in the input. As a result, the SaRcAsM pattern only has to hold within groups of alphanumeric characters. This means the starting letter of any “secondary” alphanumeric groups can be any case.

While the encoder is well defined in the capitalization throughout the whole string, the decoder needs to be able to deal with many possible styles of writing SaRcAsM text.

Edge Cases

• AbC DeF and AbC dEf -> SaRcAsM.
• Ab-Cd and Ab-cD -> SaRcAsM.
• A -> SaRcAsM.
• !! -> Too Short (no alphanumeric characters to judge).
• A!A and A!a -> SaRcAsM.

Arguments

• input - String slice to check for SaRcAsM.

Return

IsSarcasm dictating if the input text was SaRcAsM.

Examples

assert_matches!(is_sarcasm("AbC"), IsSarcasm::Yes(StartingCase::Uppercase));
assert_matches!(is_sarcasm("aBc"), IsSarcasm::Yes(StartingCase::Lowercase));

assert_matches!(is_sarcasm("Abc"), IsSarcasm::No);
assert_matches!(is_sarcasm("aBC"), IsSarcasm::No);

assert_matches!(is_sarcasm(""), IsSarcasm::TooShort);
assert_matches!(is_sarcasm("!!"), IsSarcasm::TooShort);