const regex = /^(?P<str_lit>(?P<begin_quote>(?P<single_quote>')|\")(?:(?(single_quote)\"|')|\\[\"']|\\[^\r\n ]|[^\"'\\\r\n])*?(?P=begin_quote))$/gm;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('^(?P<str_lit>(?P<begin_quote>(?P<single_quote>\')|\\")(?:(?(single_quote)\\"|\')|\\\\[\\"\']|\\\\[^\\r\\n ]|[^\\"\'\\\\\\r\\n])*?(?P=begin_quote))$', 'gm')
const str = `"double-quoted string"
'single-quoted string'
"unexpected EOL
'unexpected EOL
"unclosed backslash escape: \\"
"properly doubled backslash: \\\\"
"escaped ' quotes and backslash escapes \\' are \\" \\n allowed"
"\\t\\tindented code\\r\\n"
"invalid escape \\%"
"'"
"space is not a valid backslash escape: \\ "
"or newline either: \\
"hopefully there aren't any edge-cases I didn't think of"
"""oh, and single-line docstrings count as three string literals, so you would have to repeat the same expression multiple times to match it"""
"""and multi-line docstrings won't match even if you repeat the expression multiple times`;
// Reset `lastIndex` if this regex is defined globally
// regex.lastIndex = 0;
let m;
while ((m = regex.exec(str)) !== null) {
// This is necessary to avoid infinite loops with zero-width matches
if (m.index === regex.lastIndex) {
regex.lastIndex++;
}
// The result can be accessed through the `m`-variable.
m.forEach((match, groupIndex) => {
console.log(`Found match, group ${groupIndex}: ${match}`);
});
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions