Show me the actual regex implementation that escapes special characters.

The regex implementation is in [index.js:L9-L10]:

return string
	.replace(/[|\\{}()[\]^$+*?.]/g, '\\$&')
	.replace(/-/g, '\\x2d');

This uses two sequential replacements:

1. First replacement (/[|\\{}()[\]^$+*?.]/g): Escapes the main RegExp special characters by prefixing them with a backslash. The pattern matches: |, \, {, }, (, ), [, ], ^, $, +, *, ?, and .. The \\$& replacement inserts a backslash before each matched character.

2. Second replacement (/-/g): Escapes the hyphen character using \x2d (a hex escape sequence) instead of a simple backslash. According to the comment in [index.js:L7-L8], this approach is needed because a simple backslash escape would be disallowed by Unicode patterns' stricter grammar, but the hex escape is always valid.

The function also validates input type in [index.js:L2-L4], throwing a TypeError if the argument is not a string.

FOLLOW_UPS:

• Why does the hyphen use hex escape instead of backslash?
• What characters are considered RegExp special characters here?
• How does this handle Unicode characters like emojis?