tomo/docs/c-interoperability.md

C Interoperability

Tomo is intended to be used as a complete, standalone programming language, but it's also meant to be easy to integrate with existing C libraries. In order to make this possible, there are a few tools available.

Using C Libraries

In order to link against a compiled shared library, you can use use -lfoo to cause Tomo to add -lfoo to the linker flags when compiling your final executable. You can also use use <foo.h> or use ./foo.h to cause Tomo to insert a corresponding #include when compiling your code.

You can also use ./foo.c or use ./foo.S to use C or assembly source files from inside a Tomo source file.

Inline C Code

As a final escape hatch, you can use C_code to add code that will be put, verbatim in the transpiled C code generated by Tomo. There are two forms: one that creates an expression value and one that creates a block that is executed without evaluating to anything:

# Inline C block:
C_code {
    printf("This is just a block that is executed without a return value\n");
}

# Inline C expression (you must specify a type)
val := C_code : Int32 (int x = 1; x + 1)

Inline C expressions must specify a type and they can be compound statement expressions. In other words, if an inline C expression has a type, it will be enclosed with ({ ...; }) so that you can put semicolon-terminated statements before the final expression in their own scope if you want.