Functions or methods?

Question

If I\'m writing abstract data types in C, are the functions written to perform actions on these data types and exposed in the interface (.h files) called functions,

Answer 1

I've always used "method" as a synonym for "member function", which implies C++ since C has no such thing.

On the other side of the coin however, one might argue that the role of foo_alter_state in:

struct foo {
  // implementation stuff;
}; 

void foo_alter_state(struct foo *self);

was still a method operating on foos, albeit free-standing. It's basically OOP in C, but implemented by hand.

This perspective might be particularly true if struct foo; was only ever declared in headers, but not defined publicly anywhere.