XS has a reputation for being hard to access and I think it's a shame because I don't think it has to be: it's mostly that the Perl API is hard. What if you offload as much logic as possible to perl, and use XS only to expose functions to perl? That would be much easier for a casual XS writer who doesn't know anything about Perl's internals.

So, in this example I will write a simple XS module for a real-life API, in this case POSIX real-time semaphores. This allows you to synchronize data between different processes or threads. At its core the API is this:

sem_t* sem_open(const char* path, int open_flags, mode_t mode, unsigned int value);
int sem_close(sem_t *sem);
int sem_unlink(const char* path);

int sem_wait(sem_t *sem);
int sem_trywait(sem_t *sem);
int sem_post(sem_t *sem);

A week ago I attended the 2025 PTS. For me it was a different PTS than the previous ones.

Firstly because it was my first PTS without Abe Timmerman. He was a regular in both the PTS (as maintainer of Test::Smoke), and of the Amsterdam Perl Mongers. In fact the last time I saw him was on our flight back to Amsterdam after the PTS in Lisbon last year. He was greatly missed.

Secondly, because of a question that Book asked at the very beginning of the PTS: how often we had been to the PTS before. I was one of the few who had attended more than 10 of them. Combined with the fact that several other regular attendees couldn't make it that meant that this PTS I spent more time than ever on helping others with various issues.

Now that we have set up our mbtiny configuration in the previous post, we can actually use it.

Minting a new distribution

Minting a distribution is trivial once you’ve completed the setup. It’s typically just a matter of calling mbtiny mint Foo::Bar. If needed you can override the global configuration at minting time (e.g.  mbtiny mint Foo::Bar --license BSD).

Converting an existing distribution

You can also convert an existing distribution to App::ModuleBuildTiny. In most cases that requires just two things:

App::ModuleBuildTiny is a relatively new authoring tool. It aims to be a relatively lightweight (at least to some other tools like Dist::Zilla) and newbie friendly tool. It supports two install tools: Module::Build::Tiny (obviously what it was originally designed for) and Dist::Build; it does not support ExtUtils::MakeMaker or Module::Build.

People usually don't think about Perl's type system. Some would even mistakenly claim it doesn't have one. It is, however, a most unusual one that doesn't really look like anything else.

What is a type anyway? And what is a type system? I'm not going to precisely define it here, that's for academics, but generally speaking a type is a fundamental property of a variable or value that determines what operations can and can not be done with it and what invariants it must hold. In a strong type system it is a stable trait: it can't change over the lifetime of the value/variable.

In some type systems containers are typed (such as C) and values really don't exist separate from containers. In other typed systems containers are typeless but values are typed (e.g. Python, Javascript, …). There are languages where both values and containers are typed (e.g. Java, C#), typically this means that the container constrains the values in it.

Contrary to what you might expect, Perl has the latter sort of typesystem, but with a twist.