Python and node

Author: steveklabnik

src/doc/trpl/rust-inside-other-languages.md

@@ -297,7 +297,59 @@ Next, let’s try Python!
 
 # Python
 
+Create an `embed.py` file in this directory, and put this in it:
+
+```python
+from ctypes import cdll
+
+lib = cdll.LoadLibrary("target/release/libembed.so")
+
+lib.process()
+
+print("done!")
+```
+
+Even easier! We use `cdll` from the `ctypes` module. A quick call
+to `LoadLibrary` later, and we can call `process()`.
+
+On my system, this takes `0.017` seconds. Speedy!
+
 # Node.js
 
 Node isn’t a language, but it’s currently the dominant implementation of
 server-side JavaScript.
+
+In order to do FFI with Node, we first need to install the library:
+
+```bash
+$ npm install ffi
+```
+
+After that installs, we can use it:
+
+```javascript
+var ffi = require('ffi');
+
+var lib = ffi.Library('target/release/libembed', {
+  'process': [ 'void', []  ]
+});
+
+lib.process();
+
+console.log("done!");
+```
+
+It looks more like the Ruby example than the Python example. We use
+the `ffi` module to get access to `ffi.Library()`, which loads up
+our shared object. We need to annotate the return type and argument
+types of the function, which are 'void' for return, and an empty
+array to signify no arguments. From there, we just call it and
+print the result.
+
+On my system, this takes a quick `0.092` seconds.
+
+# Conclusion
+
+As you can see, the basics of doing this are _very_ easy. Of course,
+there's a lot more that we could do here. Check out the [FFI][ffi]
+chapter for more details.