X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FAtom.java;h=55be283096ef76586322e63cff8d98b3e03ee535;hb=142b31e063c97d2d6dc141a9e687d49b7f2ab826;hp=f5b0158f603f63ce7907361287419fd174f1e3ee;hpb=b0d313eb49712b23f9c71003c96f130f23a63526;p=sbp.git diff --git a/src/edu/berkeley/sbp/Atom.java b/src/edu/berkeley/sbp/Atom.java index f5b0158..55be283 100644 --- a/src/edu/berkeley/sbp/Atom.java +++ b/src/edu/berkeley/sbp/Atom.java @@ -8,12 +8,11 @@ import edu.berkeley.sbp.*; import edu.berkeley.sbp.*; /** an element which matches exactly one input token */ -public abstract class Atom extends Element implements Topology { +public abstract class Atom extends Element implements Topology { protected abstract Topology top(); public abstract String toString(); - - public Topology toAtom() { return this; } + public StringBuffer toString(StringBuffer sb) { sb.append(this); return sb; } // Topology Thunks ////////////////////////////////////////////////////////////////////////////// @@ -31,19 +30,29 @@ public abstract class Atom extends Element implements Topology< // Subclasses ////////////////////////////////////////////////////////////////////////////// - public static class Infer extends Atom { + /** an atom which tracks the possible tokenset of some element, provided that element can only match single-token sequences */ + public static class Infer extends Atom { private final Element e; public Infer(Element e) { this.e = e; } - public Topology top() { return (Topology)e.toAtom(); } - public String toString() { return e.toString(); /* FIXME should be toAtom() */ } + public Topology top() { return (Topology)toAtom(e); } + public String toString() { return e.toString(); } } - public static class Invert extends Atom { + /** an atom which tracks the inverse of some other atom */ + public static class Invert extends Atom { private final Atom a; public Invert(Atom a) { this.a = a; } public Topology top() { return ((Topology)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; + } }