hex-literal: allow use | to start comment?

[hismito]

hex!(
    "
    31 0a 32 0a 33 0a 34 0a  35 0a 36 0a 37 0a 38 0a  |1.2.3.4.5.6.7.8.
    39 0a 31 30 0a                                    |9.10.
    "
);

It's pretty common to separates hex and ascii by |, this would enable copy-paste without any modification.

[tarcieri]

Personally I'd prefer to keep the number of comment syntaxes to a minimum for the sake of not overcomplicating the implementation

[newpavlov]

I agree. IIRC we declined request to support # for comments, so I don't think we should accept |l. Honestly, it may be worth to even completely forbid comments inside literals and instead recommend to use standard Rust comments with multi-literal hex!. Your example would look like this:

hex!(
    "31 0a 32 0a 33 0a 34 0a  35 0a 36 0a 37 0a 38 0a"  // 1.2.3.4.5.6.7.8.
    "39 0a 31 30 0a"                                    // 9.10.
);

[tarcieri]

FWIW there are several things that use the existing comment syntax. I would prefer not adding churn to remove it.

[newpavlov]

Well, hex-literal v0.3 will continue to work without any changes, so people who don't want to edit comments can simply continue to use it as-is.

Advantages of forbidding comments inside literals:

• Comments will be properly highlighted in code editors and snippets
• Significant simplification of the hex-literal code

hex-literal is quite stable, so it may be worth to consider releasing v1.0 sometime next year (though, ideally, I would like to get MSRV-dependent dependency version resolution before that).

[newpavlov]

Since we both agree regarding the OP's proposal, I will close this issue and will open a separate one for discussing potential v1.0 release.