Play with the Forth kernel projectk.py, a small file.

projectk.py

This is fun. You don't need to be very familiar with python. Go through the following steps then you will know what this Forth kernel is all about.

I don't know how many different python are out there. I am new too. Python for Windows DOS Box is a target application of projectk.py. You should have installed python 3.6 or newer. So just run it:

python.exe

projectk.py is targeting all python hosts. Here and now we focus on this one.

Type in the following lines to create a project-k VM object, check it out and list its attributes.

import projectk as vm   
vm
dir(vm) 

The first line creates an instance of project-k VM. Here we call it 'vm' yet you can choose a permanent name for your project. We can see that it has only very few attributes (methods and properties) so it's really very easy to handle.

Let's try some project-k VM methods:

vm.dictate("123")
vm.stack

vm.stack gets you the Forth VM data stack which was empty at first. vm.dictate() method is the way project-k VM receives your commands (a string). It actually is also the way we feed it an entire Forth source code file (also as a string).

So we can start to define new words:

vm.dictate("code hi print('Hello World!!') end-code")
vm.dictate("hi")

Did you know what have we done? We defined a new FORTH code word! There are a few more butilt-in functions in the VM you can use in Forth word definitions. See below Built-in functions and Global variables table for all of them.

vm.dictate("code words print([w.name for w in words['forth'][1:]]) end-code")
vm.dictate("words")

'words' is a basic Forth word (or a Forth command) that lists all words of recent vocabularies. This example shows you how to define it. We have only 4 words so far as shown on the above picture.

vm.dictate("code + push(pop(1)+pop()) end-code")
vm.dictate("code .s print(stack) end-code")  
vm.dictate('code s" push(nexttoken(\'"\'));nexttoken() end-code')
vm.dictate('s" Forth" s"  is the easist" s"  programming langage" .s + + .s')

This example demonstrates how to use built-in functions push(), pop(), nexttoken() and the 'stack' global variable which is the center of a Forth system. Below tables list and explain all of them. Did you find the last line of the above example actually uses new words ( s" .s and + ) that are just defined in prior?

Let me know (hcchen5600@gmail.com, hcchen_1471@hotmail.com) if you couldn't understand anything of the above examples. Let's see how to improve them.

Global variables and built-in functions can be seen and used in code word and colon word definitions. They are not visible outside the project-k VM. You are encouraged to read the projectk.py source code directly. It's short, interesting and with a lot of comments.

Above variables may not found in a traditional Forth system. Following ones are common Forth global variables you probably are very familiar with already .

Above functions may not be seen in a traditional Forth system and that's all of them. Following ones are from common Forth words you probably are very familiar with already.