remacs-lib

This crate contains rust replacements for the gnulib code included with the emacs codebase. This includes the c files in lib/ and lib-src/. The code in this module should be:

• Generic in functionality (not specific to elisp)
• Self contained in nature (any rust program could use the code contained in this module)

Conventions for code in this crate

When porting an existing C function, try to preserve the guarantees that function makes according to its man page. For example, the rust implementation of mkostemp (called rust_make_temp), has the interface and errno guarantees described in https://linux.die.net/man/3/mkostemp.

These functions should be in idiomatic rust, dealing with rust standard data structures. For example, if you are porting a C function of the form:

// Returns a File Descriptor based on values of x and y
int foo(int x, const char* y);

You should write something like:

pub fn good_name_for_foo(x: i32, y: &str) -> Result<File> {
    // ... 
}

pub extern "C" fn rust_foo(x: libc::c_int, y: *const libc::c_char) {
    // Convert x and y into rust equivalents.
    let valueX = ...
    let valueY = ...
    match good_name_for_foo(valueX, valueY) {
        Ok(result) => {
            // Deal with OK result according to C interface.
        }
        Err(err) => {
            // Deal with Err result according to C interface, set errno appropriately, etc.
        }
    }
}

Here good_name_for_foo can be used in any rust codebase, without having to deal with any C "baggage". rust_foo is a glue function, whose only responsibility is to convert our idomatic rust function's results to the C equivalent.