Hacking / Extending

1.1 Writing your own libraries

PocketML is not opinionated when it comes to project structure. All default libraries are in lib/.

You can also write bigger chunks of code on your pc for testing and then transfer them. Connect your phone via USB and open the folder Internal Storage/Android/data/org.test.myapp/files/.

1.2 Python interop

PocketML is compiled to python. It has access to all features of python and the libraries numpy, pygments, lark, and kivy. Python code can be included in PocketML code using %%% ... %%%. PocketML uses the PML_[varname] naming scheme internally. Python functions exported to PocketML should be named accordingly.

%%%
def half(x):
    return x / 2

PML_half = half
%%%;

let half : Number -> Number;

print (half 2)

Python code can also be used to compute values in PocketML code using the inline %% ... %% syntax. Python types are largely compatible with PocketML types.

print %%f"PocketML does not have f-strings but python does {'!'*10}"%%

Another example:

import lib.std;

# get name and greet!
input "Name:" (\nm -> print %%f"Hi, {PML_nm}!"%%)

As discussed in the Language Guide on records, one can also build a function with default arguments using python interop:

let mkVec : { x : Number, y : Number, z : Number } -> Vec;

%%%
def PML_mkVec(r):
    defaults = {"x":0,"y":0,"z":0}
    defaults.update(r)
    return np.array(list(defaults.values()))
%%%;

print $ mkVec {y=20} # => [ 0 20  0]

1.3 The editor

Extending and hacking!

The PocketML editor is accessible to the language by using python interop. The editor object can be accessed directly by the name editor. It contains the “terminalout” and “graphicalout” objects.

%%%
def cls(_):
    # example usage:
    # clear the terminal
    editor.terminalout.text = ""
%%%;
()

editor.graphicalout is the kivy object for the “Graphics” tab in the editor and can be added to / manipulated like any other kivy object.

For a better insight into accessing the graphicalout object from code, refer to the tea.ml library.