Show me the actual regex implementation that escapes special characters.

Here's the regex implementation that escapes special characters in this library:

[index.js:L9-L10]

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

The implementation uses two separate replace operations:

1. First replace (/[|\\{}()[\]^$+*?.]/g): Escapes the main RegExp special characters by prepending a backslash (\) to each one. This covers: |, \, {, }, (, ), [, ], ^, $, +, *, ?, and .

2. Second replace (/-/g): Escapes the hyphen character as \x2d (hexadecimal escape) instead of a simple backslash. This is done because a simple backslash escape for hyphens can cause issues in certain contexts like PCRE (Perl Compatible Regular Expressions) and with Unicode patterns, as explained in the test cases [test.js:L10-L20].

The function also includes input validation [index.js:L2-L4] to ensure the argument is actually a string, throwing a TypeError otherwise.

FOLLOW_UPS:

• Why does the hyphen use hex escape instead of backslash?
• What special characters does this library handle?
• How are edge cases like \0 or \c affected?