/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * This file is part of SimpleC.                                   *
 * See the file "SimpleC-LICENSE" for Copyright information and    *
 * the terms and conditions for copying, distribution and          *
 * modification of SimpleC.                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

package org.sablecc.simplec;


import java.util.*;

class Lam extends Type
{
    LinkedList args = new LinkedList();
    Variable ret = new Variable(new Ref());

    void unify(Type t)
    {
        Lam lam = (Lam) t;

        LinkedList list1 = 
            (args.size() > lam.args.size()) ? args : lam.args;
        LinkedList list2 = 
            (args.size() > lam.args.size()) ? lam.args : args;

        ListIterator i2 = list2.listIterator();
        for(ListIterator i1 = list1.listIterator(); i1.hasNext(); )
        {
            Variable v1 = ((Variable) i1.next()).ecr();

            if(i2.hasNext())
            {
                Variable v2 = ((Variable) i2.next()).ecr();

                if(v1 != v2)
                {
                    v1.join(v2);
                }
            }
            else
            {
                i2.add(v1);
                i2.next();
            }
        }

        Variable ret1 = ret.ecr();
        Variable ret2 = lam.ret.ecr();

        if(ret1 != ret2)
        {
            ret1.join(ret2);
        }
    }

    public String toString()
    {
        StringBuffer s = new StringBuffer();

        s.append("lam(");
        boolean comma = false;

        for(Iterator i = args.iterator(); i.hasNext();)
        {
            Variable v = (Variable) i.next();

            if(comma)
            {
                s.append(",");
            }
            else
            {
                comma = true;
            }

            if(v.ecr().type == Bottom.instance)
            {
                s.append("bottom");
            }
            else
            {
                s.append("T" + v.ecr().number);
            }
        }

        s.append("):");

        if(ret.ecr().type == Bottom.instance)
        {
            s.append("bottom");
        }
        else
        {
            s.append("T" + ret.ecr().number);
        }

        return s.toString();
    }
}