Handle NA_STRING

[qinwf]

No description provided.

[gagolews]

The desired strategy is to "return NA if the corresponding input is missing".

Btw, will the functions be vectorized with respect to both the "haystack" and the "needle" (e.g., n strings, 1 regex; 1 string, n regexes etc.?)

[qinwf]

Yes. Return the same result as stringi and stringr would be easier for users to learn and use. These two packages provide user-friendly APIs.

I think I can learn from stringi package stri__recycling_rule function.

[gagolews]

sure, give it a try;

BTW, this is not an exported function but in some of the cases you may call stringi functions from C code directly, take a look at https://github.com/gagolews/ExampleRcppStringi

[tdhock]

about vectorizing "1 string, n regexes" -- what is the use case? I only use the other "n strings, 1 regex" version

[tdhock]

btw for the n string, n regexes case there is https://github.com/tdhock/revector