Function parse_pattern 

pub fn parse_pattern(text: &str, utf16: bool) -> Result<Pattern, String>

A find’s pattern from what was typed:

• 0x and hex digits, or two or more space-separated hex pairs: bytes, where ?? matches any byte (de ad ?? ef);
• anything else, or text in double quotes: the text’s bytes, UTF-8, or UTF-16 little-endian when utf16 is set.