Flag to make python optional as build dependency

[d-musique]

Hello. The re2c package requires python for docs and testing. If the test targets can be disabled, the requirement of python can be dropped as well. This introduces the flag RE2C_BUILD_TESTS for this purpose.

The deeper purpose is to facilitate integration of re2c into vcpkg, which trivializes access to re2c on a Windows development environment.

[skvadrik]

Thanks!

[skvadrik]

Can you squash the three commits into one before merging?

[d-musique]

Can you squash the three commits into one before merging?

@skvadrik Sure, yes.

If you allow me a question, also relevant to packaging: the option RE2C_BUILD_LIBS installs a lib currently without headers.

Is this something that is supposed to be accessible to developers by public API?

I need to ask, because it conditions whether package re2c must be placed or not in the "tool-only" category, which implies some significant changes.

[skvadrik]

If you allow me a question, also relevant to packaging: the option RE2C_BUILD_LIBS installs a lib currently without headers.

Is this something that is supposed to be accessible to developers by public API?

I need to ask, because it conditions whether package re2c must be placed or not in the "tool-only" category, which implies some significant changes.

libre2c is an experimental library; I'm not aware of it being used in the wild. It exists for the sake of testing and benchmarking various internal regexp-matching algorithms against other libraries that have POSIX interface (we cannot use a lexer generator in that case, as it will be comparing ahead-of-time code generation to just-in-time one, which is meaningless). The library is not stable. One day it may become useful, but for now I wouldn't bother packaging it, unless you have some specific uses in mind.

[d-musique]

Thank you!