X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FAtom.java;h=daa3d495e75c50a6dc04b6f31ccd7b23c1bc116e;hp=037dfaa7f2df67d62946d31da9ccda8494b93217;hb=2c1c0293545f3d12c23220fd05c663e6aa3f3de1;hpb=2690f6c749f117a103c57d651d89f1b4fbf1316d diff --git a/src/edu/berkeley/sbp/Atom.java b/src/edu/berkeley/sbp/Atom.java index 037dfaa..daa3d49 100644 --- a/src/edu/berkeley/sbp/Atom.java +++ b/src/edu/berkeley/sbp/Atom.java @@ -7,41 +7,24 @@ import edu.berkeley.sbp.util.*; import edu.berkeley.sbp.*; import edu.berkeley.sbp.*; -/** an element which matches exactly one input token */ -public abstract class Atom extends Element implements Topology { +/** + * an element which matches some set of one-token-long input strings. + * + *

+ * This class is a topology over itself (yes, that's sort of Frege'd + * up) so that Atoms can be intersected and unioned with each other + * to result in other Atom's (rather than raw Topology's, which + * are not Elements). If you want the latter, use the + * getTokenTopology() method. + *

+ */ +public abstract class Atom extends Element implements Topology> { + + /** the set (topology) of tokens that can match this element */ + public abstract Topology getTokenTopology(); + + StringBuffer toString(StringBuffer sb) { sb.append(this); return sb; } - private final Topology rt; - - public Atom(Topology rt) { this.rt = rt; } - - void reachable(HashSet h) { /* do-nothing */ } - - public Topology toAtom() { return dup(); } - - /** equality is based on the underlying Topology */ - public int hashCode() { return rt.hashCode(); } - - /** equality is based on the underlying Topology */ - public boolean equals(Object o) { return o != null && o instanceof Atom && ((Atom)o).rt.equals(rt); } - - /** declared abstract to force subclasses to override it in a useful manner */ - public abstract String toString(); - - // Topology Thunks ////////////////////////////////////////////////////////////////////////////// - - public void add(Topology t) { rt.add(t); } - public void add(T t) { rt.add(t); } - public void remove(Topology t) { rt.remove(t); } - public void remove(T t) { rt.remove(t); } - public Topology dup() { return rt.dup(); } - public boolean contains(T v) { return rt.contains(v); } - public Topology fresh() { return rt.fresh(); } - public Topology intersect(Topology t) { return rt.intersect(t); } - public Topology minus(Topology t) { return rt.minus(t); } - public Topology union(Topology t) { return rt.union(t); } - public Topology complement() { return rt.complement(); } - public boolean disjoint(Topology t) { return rt.disjoint(t); } - public boolean containsAll(Topology t) { return rt.containsAll(t); } - } +