when have "\" in regex, protoc will throw err" Invalid escape sequence"

[chaoweili]

for example: repeated string pic_url_list = 2 [(validator.field) = {regex: "/^(https?:\/\/)([\da-z\.-]+)\.([a-z\.]{2,6})([\/\w\.-]*)*\/?$/"}];

this will return error: _feedsprotocol.proto:323:83: Invalid escape sequence in string literal.

if i do not use "\", everything works fine.

[erstaples]

I'm running into the same thing, but not using quotes gives me a different error:

pkg/proto/nks.proto:48:50: Error while parsing option value for "field": Expected string, got: /

Is there a fix for this?

[Helcaraxan]

Hello @chaoweili and @erstaples. I've only very recently picked up this repository for maintenance. I'll try to address this issue in the near term.

[Helcaraxan]

The quick fix in the mean time should be to specify your regex within back-ticks instead of double-quotes.

[erstaples]

Thanks for the response, @Helcaraxan . That doesn't work for me, unfortunately. My compiler really wants those quotes:

builder_api/builder_api.proto:113:29: Error while parsing option value for "field": Expected string, got: `

Here's the field in question:

    string kubernetes_version = 8 [
        (validator.field) = { regex: `/^v[0-9]{1}\.[0-9]{1,2}\.[0-9]{1,2}$/` }
    ];

[Helcaraxan]

Reading your regular expression (RE) a few questions come to mind:

• Why the / at the front and the head of the RE? The ^ and $ already express the need to match an entire line?
• I believe that the following should work and give you the result you want:

  string kubernetes_version = 8 [
      (validator.field) = { regex: "^v[0-9]{1}\\.[0-9]{1,2}\\.[0-9]{1,2}$" }
  ];

Bear in mind that the string you provide in the regex validator is reused as is to instantiate a regexp.Regexp from the Go standard library so the RE should follow Go's RE syntax. Just wanted to make sure that was well understood, just in case. 🙂

[AlekSi]

\\ in .proto file generated valid regex in Go code. Maybe add that to documentation and close this issue?