samer@0: /*
samer@0:  *	ConsoleEnvironment.java	
samer@0:  *
samer@0:  *	Copyright (c) 2000, Samer Abdallah, King's College London.
samer@0:  *	All rights reserved.
samer@0:  *
samer@0:  *	This software is provided AS IS and WITHOUT ANY WARRANTY; 
samer@0:  *	without even the implied warranty of MERCHANTABILITY or 
samer@0:  *	FITNESS FOR A PARTICULAR PURPOSE.
samer@0:  */
samer@0: 
samer@0: package samer.core.util;
samer@0: import  samer.core.*;
samer@0: import  java.io.*;
samer@0: 
samer@0: /**	
samer@0:   *	Environment which provides access to the user
samer@0:   *	using the standard input and output
samer@0:   */
samer@0: 
samer@0: public class ConsoleEnvironment extends Environment
samer@0: {
samer@0: 	BufferedReader	in;
samer@0: 
samer@0: 	public ConsoleEnvironment(Environment parent) {
samer@0: 		super(parent,parent.node());
samer@0: 		in=new BufferedReader(new InputStreamReader(System.in));
samer@0: 	}
samer@0: 
samer@0: 	public Datum datum() { return new Texton("",Null); } // ??
samer@0: 	public Datum datum(String name) {
samer@0: 		// should check if use is willing to supply value
samer@0: 		// if not return Null (or bad score)
samer@0: 		return new Texton(rel(name),parent.datum(abs(name))); 
samer@0: 	}
samer@0: 
samer@0: 	private class Texton implements Datum 
samer@0: 	{
samer@0: 		String	name;			// name of this Binding
samer@0: 		Datum		inherited;	// parent's binding
samer@0: 
samer@0: 		public Texton(String nm, Datum inh) { name=nm; inherited=inh; }
samer@0: 
samer@0: 		public String name()  { return this.name; }
samer@0: 		public int	  score() { return 32; } // less than perfect match
samer@0: 
samer@0: 		public Object get(Codec c, Object def)
samer@0: 		{
samer@0: 			if (def==null) def=inherited.get(c,def);
samer@0: 
samer@0: 			Shell.push(parent);
samer@0: 			try {
samer@0: 				System.out.println("Enter value for "+name);
samer@0: 				if (def!=null) {
samer@0: 					System.out.println("Default value is: " + def);
samer@0: 				}
samer@0: 				String instring=in.readLine();
samer@0: 
samer@0: 				if (instring.equals(".")) {
samer@0: 					System.out.println("returning: "+def);
samer@0: 					return def;
samer@0: 				}
samer@0: 				return c.decode(instring);
samer@0: 			} catch (Exception ex) { 
samer@0: 				Shell.trace(ex.toString());
samer@0: 				throw new Error("get "+name);
samer@0: 			} finally { Shell.pop(); }
samer@0: 		}
samer@0: 
samer@0: 		public void get(Autocoder obj)
samer@0: 		{
samer@0: 			Shell.push(parent);
samer@0: 			try {
samer@0: 				System.out.println("Enter value for "+name);
samer@0: 				System.out.println("Current value is: " + obj.string());
samer@0: 				String instring=in.readLine();
samer@0: 				if (!instring.equals(".")) obj.decode(instring);
samer@0: 			} catch (Exception ex) { 
samer@0: 				Shell.trace(ex.toString());
samer@0: 				throw new Error("get "+name);
samer@0: 			} finally { Shell.pop(); }
samer@0: 		}
samer@0: 	}
samer@0: }
samer@0: