pyterpreter

A tree-walk interpreter for a toy language, written in good ol' Python.

To fire up the REPL:

$ python3  src/pyterpreter/preter.py
>>> var a = 10;
>>> print var;
10.0

To execute a file, add an argument for the file's location:

$ python3 src/pyterpreter/preter.py samples/print_somethings.pr

Things that work right now

Variables

Only two data types - numbers(all of which are floats) and strings

>>> var a = 10;
>>> var b = 0.5;
>>> print a + b;
10.5
>>> var c = "Hello, Planet";
>>> print c;
Hello, Planet
>>> var str = "talk to ";
>>> var hand = "the hand!";
>>> print str + hand;
talk to the hand!
>>> print str + "the hand!";
talk to the hand!

Control flow

var first = 5;
var second = 10;
if(first > second){
    print "oh no";
}
else{
    print "perfect";
}

Loops

var c = 10;
while(c > 0){
    print c;
}

for(var i=16; i>=1; i = i / 2){
    print i;
}

Based on Crafting Interpreters