DLOAD.md

Writing C methods for Hermes

As mentioned before, Hermes can execute functions written in C, and you can load them using the dload method:

dload("librequests.so", "httpget");

Examples

Lets say we want to write a method in C that gives us a float, and then we want to call this method from Hermes. Here is how we write that method:

// main.c

#include <hermes/AST.h>
#include <hermes/dynamic_list.h>


AST_T* getpi(AST_T* self, dynamic_list_T* args)
{
    AST_T* float_ast = init_ast(AST_FLOAT);
    float_ast->float_value = 3.14;

    return float_ast;
}

Now, you can compile this code like so:

gcc -g -Wall -rdynamic -shared -fPIC -o libgetpi.so main.c

Now you can use the created libgetpi.so file in hermes like this:

dload("libgetpi.so", "getpi");


float PI = getpi();