PyForth: A Forth interpreter written in Python
What will I talk about?
- What is Forth?
- PyForth
- The Forth interpreter + some PyForth snippets
What is Forth?
- Stack based programming language
- ~backwards lisp
- You can access and manipulate the underlying structures
1 2 +2 PLUS: PLUS + ;PyForth
- Forth written in Python
- repl and web version
.S DUP * + - = < > OVER SWAP ROT DROP NIP TUCK 2DUP MOD
: ; ! @ , > R R> R@ R0 IF ELSE THEN DO LOOP I J
.DDEMO
- Dictionary
- Stack
- Return stack
- Input stream
The Forth interpreter
def INTERPRET():
WORD()
FIND()
if abs(POP())
EXECUTE()
else:
NUMBER()
PyForth: Interpret
while input_stream:
if COMPILE:
COMPILE()
else:
INTERPRET()1 2 3 DUP
: SQUARED DUP * ;
4 SQUARED