Show me the actual regex implementation that escapes special characters.

The regex implementation that escapes special characters is in [index.js:L9-L10]:

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

This uses two separate regex replacements:

1. First replacement (/[|\\{}()[\]^$+*?.]/g): Escapes the core RegExp special characters by prefixing them with a backslash. The character class includes:

   • | (alternation)
   • \ (backslash)
   • {} (quantifiers)
   • () (groups)
   • [] (character classes)
   • ^ (anchor)
   • $ (anchor)
   • +*?. (quantifiers and wildcards)

2. Second replacement (/-/g): Escapes the hyphen (-) as \x2d (hex escape) instead of a simple backslash escape. This is done for compatibility with PCRE and Unicode patterns, as documented in the tests [test.js:L10-L13] and [test.js:L15-L20].

The function is minimal and intentional—it only escapes what's necessary, expecting developers to insert the escaped string at safe positions in a RegExp.

FOLLOW_UPS:

• Why does the hyphen use \x2d instead of \-?
• What characters are NOT escaped by this function?
• Can this handle emoji and Unicode safely?