checkpoint

[sbp.git] / src / edu / berkeley / sbp / Atom.java

diff --git a/src/edu/berkeley/sbp/Atom.java b/src/edu/berkeley/sbp/Atom.java
index a5f7e87..0a8ad12 100644 (file)
--- a/src/edu/berkeley/sbp/Atom.java
+++ b/src/edu/berkeley/sbp/Atom.java
@@ -7,49 +7,19 @@ 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<T> extends Element implements Topology<T> {
-
-    protected abstract Topology<T> top();
-    public    abstract String toString();
-
-    // Topology Thunks //////////////////////////////////////////////////////////////////////////////
-
-    public Topology<T>       unwrap()                   { return top().unwrap(); }
-    public Topology<T>       empty()                    { return top().empty(); }
-    public boolean           contains(T v)              { return top().contains(v); }
-    public Topology<T>       intersect(Topology<T> t)   { return top().intersect(t); }
-    public Topology<T>       minus(Topology<T> t)       { return top().minus(t); }
-    public Topology<T>       union(Topology<T> t)       { return top().union(t); }
-    public Topology<T>       complement()               { return top().complement(); }
-    public boolean           disjoint(Topology<T> t)    { return top().disjoint(t); }
-    public boolean           containsAll(Topology<T> t) { return top().containsAll(t); }
-    public int               hashCode()                 { return top().hashCode(); }
-    public boolean           equals(Object o)           { return o != null && o instanceof Atom && ((Atom)o).top().equals(top()); }
-
-    // Subclasses //////////////////////////////////////////////////////////////////////////////
-
-    public static class Infer<T extends Input> extends Atom<T> {
-        private final Element e;
-        public Infer(Element e) { this.e = e; }
-        public Topology<T> top() { return (Topology<T>)toAtom(e); }
-        public String toString() { return e.toString(); /* FIXME should be toAtom() */ }
-    }
-    
-    public static class Invert<T extends Input> extends Atom<T> {
-        private final Atom<T> a;
-        public Invert(Atom<T> a) { this.a = a; }
-        public Topology<T> top() { return ((Topology<T>)a.top()).complement(); }
-        public String toString() { return "~"+a; }
-    }
-
-    static Topology toAtom(Element e) {
-        if (e instanceof Atom) return (Atom)e;
-        if (e instanceof Sequence) return ((Sequence)e).toAtom();
-        Topology ret = null;
-        for(Sequence s : (Union)e)
-            ret = ret==null ? toAtom(s) : ret.union(s.toAtom());
-        return ret;
-    }
+/**
+ *  <font color=green>an element which matches some set of one-token-long input strings</font>.
+ *
+ *  This class is a topology over itself so that Atoms can be
+ *  intersected and unioned with each other to result in other
+ *  Atom<T>'s (rather than raw Topology<T>'s, which are not Elements).
+ *  If you want the latter, use the getTokenTopology() method.
+ */
+public abstract class Atom<T> extends Element implements Topology<Atom<T>> {
+
+    /** the set (topology) of tokens that can match this element */
+    public abstract Topology<T>  getTokenTopology();
+
+    public abstract StringBuffer toString(StringBuffer sb);
 }