ShowTreeVisitor.java

/*Name: Sachin Subhas Nambisan & Saarthi Baluja */
import absyn.*;

import java.lang.String;
import java.io.ByteArrayOutputStream;
import java.io.PrintStream;

public class ShowTreeVisitor implements AbsynVisitor {

    final static int SPACES = 4;
    private ByteArrayOutputStream baos = new ByteArrayOutputStream();
    private PrintStream ps = new PrintStream(baos); //creates a new stream to hold output
    private PrintStream prev = System.out; //saves the prevois stream

    public ShowTreeVisitor(){
        System.setOut(ps); //all output now goes here
    }

    private void indent(int level) {
        for (int i = 0; i < level * SPACES; i++)
            System.out.print(" ");
    }

    public void visit(ExpList expList, int level) {
        while (expList != null && expList.head != null) {
            expList.head.accept(this, level);
            expList = expList.tail;
        }
    }

    public void visit(AssignExp exp, int level) {
        indent(level);
        System.out.println("AssignExp:");
        level++;
        exp.lhs.accept(this, level);
        exp.rhs.accept(this, level);
    }

    public void visit(IfExp exp, int level) {
        indent(level);
        System.out.println("IfExp:");
        level++;
        exp.test.accept(this, level);
        exp.thenpart.accept(this, level);
        if (exp.elsepart != null)
            exp.elsepart.accept(this, level);
    }

    public void visit(IntExp exp, int level) {
        indent(level);
        System.out.println("IntExp: " + exp.value);
    }

    public void visit(OpExp exp, int level) {
        indent(level);
        System.out.print("OpExp:");
        switch (exp.op) {
            case OpExp.PLUS:
                System.out.println(" + ");
                break;
            case OpExp.MINUS:
                System.out.println(" - ");
                break;
            case OpExp.MUL:
                System.out.println(" * ");
                break;
            case OpExp.DIV:
                System.out.println(" / ");
                break;
            case OpExp.EQ:
                System.out.println(" = ");
                break;
            case OpExp.LT:
                System.out.println(" < ");
                break;
            case OpExp.GT:
                System.out.println(" > ");
                break;
            default:
                System.out.println("Unrecognized operator at line " + exp.row + " and column " + exp.col);
        }
        level++;
        exp.left.accept(this, level);
        exp.right.accept(this, level);
    }

    public void visit(RepeatExp exp, int level) {
        indent(level);
        System.out.println("RepeatExp:");
        level++;
        exp.exps.accept(this, level);
        exp.test.accept(this, level);
    }

    public void visit(VarExp exp, int level) {
        indent(level);
        System.out.println("VarExp: ");
        exp.value.accept(this, level);
    }

    public void visit(WriteExp exp, int level) {
        indent(level);
        System.out.println("WriteExp:");
        exp.output.accept(this, ++level);
    }

    public void visit(NameTy t, int level) {
        indent(level);

        // Get the string of the represented int
        String typeString = "";
        if (t.type == 0) {
            typeString = "int";
        } else {
            typeString = "void";
        }

        System.out.println("NameTy: " + typeString);
    }

    public void visit(VarDecList varDecList, int level) {
        while (varDecList != null && varDecList.head != null) {
            varDecList.head.accept(this, level);
            varDecList = varDecList.tail;
        }
    }

    public void visit(DecList decList, int level) {
        while (decList != null && decList.head != null) {
            decList.head.accept(this, level);
            decList = decList.tail;
        }
    }

    public void visit(ArrayDec arr, int level) {
        indent(level);
        System.out.println("ArrayDec: ");
        arr.type.accept(this, ++level);
        indent(++level);
        System.out.println("Name: " + arr.name);
        if (arr.size != null)
            arr.size.accept(this, ++level);
    }

    public void visit(SimpleDec dec, int level) {
        indent(level);
        System.out.println("SimpleDec: " + String.valueOf(dec.name));
        dec.type.accept(this, ++level);
    }

    public void visit(FunctionDec dec, int level) {
        indent(level);
        System.out.println("FunctionDec: ");

        dec.type.accept(this, ++level);
        indent(++level);
        System.out.println("Name: " + dec.func);

        dec.params.accept(this, ++level);
        dec.body.accept(this, ++level);
    }

    public void visit(CompoundExp exp, int level) {
        indent(level);
        System.out.println("CompoundExp: ");
        if (exp.decs != null)
            exp.decs.accept(this, ++level);
        if (exp.exps != null)
            exp.exps.accept(this, ++level);
    }

    public void visit(ReturnExp e, int level) {
        indent(level);
        System.out.println("ReturnExp: ");
        if (e.exp != null)
            e.exp.accept(this, ++level);
    }

    public void visit(WhileExp exp, int level) {
        indent(level);
        System.out.println("WhileExp: ");

        exp.body.accept(this, ++level);
        exp.test.accept(this, ++level);
    }

    public void visit(CallExp exp, int level) {
        indent(level);
        System.out.println("CallExp: " + exp.func + " ");
        exp.args.accept(this, ++level);
    }


    public void visit(NilExp exp, int level) {
        indent(level);
        System.out.println("NilExp: ");
    }

    public void visit(IndexVar var, int level) {
        indent(level);
        System.out.println("IndexVar: " + var.name + " ");
        var.index.accept(this, ++level);
    }

    public void visit(SimpleVar var, int level) {
        indent(level);
        System.out.println("SimpleVar: " + var.name + " ");
    }

    public void visit(ErrorExp exp, int level ){
        indent(level);
        System.out.println("null");
    }

    public String treeString(){
        System.out.flush();
        System.setOut(prev);
        return baos.toString();
    }
}