1 package edu.berkeley.sbp;
4 import java.lang.reflect.*;
5 import java.lang.ref.*;
6 import edu.berkeley.sbp.*;
7 import edu.berkeley.sbp.util.*;
9 /** a stream of tokens to be parsed */
10 public interface Input<Token> {
12 /** returns the token just beyond the current location and advances beyond it */
13 public Token next() throws IOException;
15 /** returns the location the input stream is currently at */
16 public Location<Token> getLocation();
18 /** a location <i>between tokens<i> in the input stream */
19 public static interface Location<Tok> extends Comparable<Location> {
20 public String toString();
22 /** an implementation of Location for a cartesian grid (row, col) */
23 public static class Cartesian<Tok> implements Location<Tok>, Comparable<Location> {
24 protected final int row;
25 protected final int col;
26 public String toString() { return row+":"+col; }
27 public int getCol() { return col; }
28 public int getRow() { return row; }
29 public Cartesian(int col, int row) { this.row = row; this.col = col; }
30 public int compareTo(Location loc) throws ClassCastException {
31 if (!(loc instanceof Cartesian)) throw new ClassCastException();
32 Cartesian<Tok> c = (Cartesian<Tok>)loc;
33 if (row < c.row) return -1;
34 if (row > c.row) return 1;
35 if (col < c.col) return -1;
36 if (col > c.col) return 1;
42 public static class Region<Loc extends Location> /* implements Topology<Location<Tok>> */ {
43 public final Loc start;
45 public Region(Loc a, Loc b) {
46 switch(a.compareTo(b)) {
48 case 0: start=a; end=b; return;
49 case 1: start=b; end=a; return;
50 default: throw new Error("impossible");