Here you can author libraries for the Espruino with native code.

For more information on the actual build process, see the build process page

To get you started, here are some steps that can be made to enable Hello.world() in Espruino. Of course you have guessed that it will print "Hello World!" to the console. Let's get on with it!

We'll create a new folder libs/hello. In this directory, we'll create our .h and .c files.

jswrap_hello.h

void jswrap_hello_world();

jswrap_hello.c

#include "jswrap_hello.h"  // We need the declaration of the jswrap_hello_world function
#include "jsinteractive.h" // Pull inn the jsiConsolePrint function

// Let's define the JavaScript class that will contain our `world()` method. We'll call it `Hello`
/*JSON{
  "type" : "class",
  "class" : "Hello"
}*/

// Now, we define the `jswrap_hello_world` to be a `staticmethod` on the `Hello` class
/*JSON{
  "type" : "staticmethod",
  "class" : "Hello",
  "name" : "world",
  "generate" : "jswrap_hello_world"
}*/
void jswrap_hello_world() {
    jsiConsolePrint("Hello World!\r\n");
}

You can add more files here if you need. It's up to you!

Go to line 606 and append

INCLUDE += -I$(ROOT)/libs/hello
WRAPPERSOURCES += libs/hello/jswrap_hello.c #you can add more files here if your library depend on them

If you want to make a pull request for your new library you'll need to make a ifdef guard for it, and specify which platforms should have access to your library. To see it in action, follow the USE_TRIGGER definition.

First run make, now you can run ./espruino and test your new Hello.world() command.

>Hello.world()
Hello World!
undefined