quoted-string

This crate provides utilities to handle quoted strings like such appearing in Mediat Types (both MIME (i.e. Mail) and HTTP). As there are many small but significant differences in different specifications this crate does not provide a specific implementation. Instead a QuotedStringSpec trait is exposed. Implementing it (on zero-sized structs) should allow the usage with any quoted-string specification.

Available functionality contains

• quote_if_needed (&quote): quotes content (if needed), the UnquotedValidator part of QuotedStringSpec can be used to specify which values are valid without needing to be representated as a quoted string. E.g. in a Media Type a parameter value of abc can and should be directly represented on benefit of quoted_if_needed is that it returns a Cow so the string is only copied if it actually needs to be represented as quoted string.

• to_content: retrieve the content of a quoted string which means that the surrounding '"' quotes will be removed and any quoted-pair (e.g. "\\\""/r#"\""#) will be replaced with it's value. This function returns Cow::Borrowed if there are no quoted-pairs preventing needless allocations.

• ContentChars: an iterator over the chars of the content of a quoted-string, i.e. it will strip the surrounding DQUOTEs and will ()on the fly) unquote quoted-pais not needing any extra memory allocations. This can be used to semantically compare two quoted strings regardless of how they used quoted-pairs, it implements Eq.

• parse (&validate): parses a quoted-string positioned at the start of the input. It is written to be easily integrable with nom (through does not require nom in any way, using it standalone is as easy)

Example

```rust extern crate quoted_string;

// we use a QuotedStringSpec provided for testing here, // not that it's made to hitt some edcases in a simple way // so it does not correspond to any used real Spec use quotedstring::testutils::TestSpec; type Spec = TestSpec;

use quotedstring::{parse, quote, quoteifneeded, tocontent};

fn main() { let res = parse::("\"quoted\\"st\ring\"; tail=x").unwrap(); let qs = res.quotedstring; asserteq!(qs, "\"quoted\\"st\ring\""); asserteq!(res.tail, "; tail=x"); let content = tocontent::(qs) .expect("[BUG] tocontent is guaranteed to succeed if input is a valid quoted string"); asserteq!(content, "quoted\"string"); let (requoted, meta) = quote::(&*content) .expect("[BUG] quote is guaranteed to succeed if the input is representable in a quoted string"); asserteq!(requoted, "\"quoted\\"string\"");

// TestSpec specifies us-ascii words with 6 letters need no quoting
let (out, _meta) = quote_if_needed::<Spec>("simple").unwrap();
assert_eq!(&*out, "simple");

}

```

License

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

Change Log

• 0.3.0: Made the crate independent of any specific quoted-string specification by introducing QuotedStringSpec as there are to many differences between quoted-string's in Media Type occurring in HTTP and thus occurring in MIME (Mail)