Menu
I do have following string:
\"lengthSeconds\":\"2664\"
which I would like to match with this regexp:
Regex::new("lengthSeconds\\\":\\\"(\\d+)\\\"")
I even tried this:
Regex::new(r#"lengthSeconds\":\"(\d+)\""#)
but I'm getting this:
regex parse error:
lengthSeconds\":\"(\d+)\"
^^
error: unrecognized escape sequence
What's wrong with the regexp pattern?
954
But Clippy uses the parser of rust-lang/regex to detect invalid regex. This means the regex parser fails to parse what seems to be valid regex.
In Rust, it can sometimes be a pain to pass regular expressions around if they're used from inside a helper function. Instead, we recommend using the lazy_staticcrate to ensure that regular expressions are compiled exactly once. For example:
This crate can handle both untrusted regular expressions and untrusted search text. Untrusted regular expressions are handled by capping the size of a compiled regular expression. (See RegexBuilder::size_limit.) Without this, it would be trivial for an attacker to exhaust your system's memory with expressions like a{100}{100}{100}.
This example also demonstrates the utility of raw strings in Rust, which are just like regular strings except they are prefixed with an r and do not process any escape sequences. For example, "\d" is the same expression as r"\d". It is an anti-pattern to compile the same regular expression in a loop since compilation is typically expensive.
By using r#..#, you treat your string as a raw string and hence do not process any escapes. However, since backslashes are special characters in Regex, the Regex expression itself still requires you to escape backslashes. So this
Regex::new(r#"\\"lengthSeconds\\":\\"(\d+)\\""#)
is what you want.
Alternatively, you could write
Regex::new("\\\\\"lengthSeconds\\\\\":\\\\\"(\\d+)\\\\\"").unwrap();
to yield the same result.
See this example on Rust Playground
163
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
