Assignment 2 Solution

What Needs to be submitted and Completeness:
All submitted assignments must actually work for even partial credit.

•    Your .g4 grammar file
•    Your python code.. Feel free to Zip up your entire working directory.
•    Screen Shot of the Turtle Drawing

Assignment Motivation:
•    Write a simple language that can be compiled directly a turtle/tool path. 
•    Write a formal grammar
•    Compile a formal grammar into language specific libraries
•    Code a "G" code compiler
•    Resume Building
•    Formal Grammar
•    Compiler Design and Implementation
•    Antlr
•    Python
•    G Codes
 current position
•    Write a test input file that draws a square 
•    Screen Shot the Square
•    Grade of B
•    Grade of C plus implement one additional G-CODE, for Example:
•    G28
•    F
•    Z
•    Output should demonstrate the additional implemented code
•    Grade of A
•    Grade of B plus at least one more G-Code
•    Output something more interesting than a square
The Assignment Resources:
•    G Code Reference
•    https://en.wikipedia.org/wiki/G-code
•    If you need Java
•    https://www.oracle.com/java/technologies/downloads/#jdk17-mac
•    If you need Python
•    https://www.anaconda.com/products/individual
•    Antlr Getting Started
•    https://github.com/antlr/antlr4/blob/master/doc/getting-started.md
•    Example Calculator
•    https://medium.com/@raguiar2/building-a-working-calculator-in-python-with-antlr-d879e2ea9058
•    Python Turtle Library
•    https://docs.python.org/3/library/turtle.html
•    Get Antlr jar
•    curl -O https://www.antlr.org/download/antlr-4.9-complete.jar
•    Setup Alias in linux.. Anrtlr "Getting Started" above shows how to do on windows
•    alias antlr4='java -Xmx500M -cp "./antlr-4.9-complete.jar:$CLASSPATH" org.antlr.v4.Tool'
•    alias grun='java -Xmx500M -cp "./antlr-4.9-complete.jar:$CLASSPATH" org.antlr.v4.gui.TestRig'
•    Generate Lexer, Parser, Visitor
•    antlr4 -Dlanguage=Python3 -visitor turtle.g4
•    NEEDED!!! Load Antlr python runtime libs
•    pip install antlr4-python3-runtime

turtle.g4

grammar turtle;

start : expr | <EOF> ;

expr     : 'turtle' x_cord=NUMBER y_cord=NUMBER #drawlineExpr    
         | 'print' x_cord=NUMBER y_cord=NUMBER #printlineExpr    
         ;
NUMBER : ('0' .. '9') + ('.' ('0' .. '9') +)? ;

turtle_test (input file)
turtle 100 200

turtle 300 400

print 3 4

run_me.py
from antlr4 import * 
from turtleLexer import turtleLexer
from turtleParser import turtleParser
from turtleVisitor import turtleVisitor
import time

def main():
    lexer = turtleLexer (FileStream("turtle_test"))
    token_stream = CommonTokenStream(lexer)
    parser = turtleParser(token_stream)
    visitor = turtleVisitor()

   
    while True: 
        tree = parser.start()
        if tree.expr() == None:
            break
        print(tree.toStringTree(recog=parser))
        visitor.visit(tree)

    time.sleep(2)

if __name__ == '__main__':
    main()

turtleVisitor.py
# Generated from turtle.g4 by ANTLR 4.9
from antlr4 import *
from turtleAst import * 
if __name__ is not None and "." in __name__:
    from .turtleParser import turtleParser
else:
    from turtleParser import turtleParser

# This class defines a complete generic visitor for a parse tree produced by turtleParser.

import turtle
skk = turtle.Turtle()

 
class turtleVisitor(ParseTreeVisitor):

    # Visit a parse tree produced by turtleParser#start.
    def visitStart(self, ctx:turtleParser.StartContext):
        return self.visitChildren(ctx)


    # Visit a parse tree produced by turtleParser#drawlineExpr.
    def visitDrawlineExpr(self, ctx:turtleParser.DrawlineExprContext):
        target_x = int(ctx.x_cord.text)
        target_y = int(ctx.y_cord.text)
        cur_pos = skk.pos() 
        if target_x > cur_pos[0]:
            skk.right(target_x - cur_pos[0])
        else:
            skk.left(cur_pos[0] - target_x)

        if target_y > cur_pos[0]:
            skk.forward(target_y - cur_pos[0])
        else:
            skk.backward(cur_pos[0] - target_y)

        return self.visitChildren(ctx)


    # Visit a parse tree produced by turtleParser#printlineExpr.
    def visitPrintlineExpr(self, ctx:turtleParser.PrintlineExprContext):
        print(f"Draw Line to {ctx.x_cord.text} {ctx.y_cord.text}") 
        return self.visitChildren(ctx)



del turtleParser