+ // Escape characters with special meaning either inside or outside character sets.
+ // Use a simple backslash escape when it’s always valid, and a \unnnn escape when the simpler form would be disallowed by Unicode patterns’ stricter grammar.
+ return string
+ .replace(/[|\\{}()[\]^$+*?.]/g, '\\$&')
+ .replace(/-/g, '\\x2d');