X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FWalk.java;h=04e36aeb47f1aae6e3db58083fdeb67a80b65cd1;hb=8ac1795e6098dcf10b94a854351162695181b83d;hp=db76747d04fd98d92f30deb8c1c744eae70e7adf;hpb=8a9fc9f2357e54052374cf2ef003630a486a6c0a;p=sbp.git

diff --git a/src/edu/berkeley/sbp/Walk.java b/src/edu/berkeley/sbp/Walk.java
index db76747..04e36ae 100644
--- a/src/edu/berkeley/sbp/Walk.java
+++ b/src/edu/berkeley/sbp/Walk.java
@@ -75,9 +75,9 @@ abstract class Walk<T> {
     }
 
 
-    // Token-Set //////////////////////////////////////////////////////////////////////////////
+    // Input-Set //////////////////////////////////////////////////////////////////////////////
 
-    static abstract class WalkTokenSet<Tok extends Token> extends Walk<Topology<Tok>> {
+    static abstract class WalkTokenSet<Tok extends Input> extends Walk<Topology<Tok>> {
         public Topology<Tok> cs;
         public WalkTokenSet(Topology<Tok> cs)          { this.cs = cs; }
         public WalkTokenSet(Topology<Tok> cs, Cache c) { super(c); this.cs = cs; }
@@ -85,7 +85,7 @@ abstract class Walk<T> {
         public Topology<Tok> walkAtom(Atom r)          { cs = cs.union(r); return cs; }
     }
 
-    class First<Tok extends Token> extends WalkTokenSet<Tok> {
+    static class First<Tok extends Input> extends WalkTokenSet<Tok> {
         public First(Topology<Tok> cs, Walk.Cache cache) { super(cs, cache); }
         public Topology<Tok> sequence(Sequence seq) {
             for(Position p = seq.firstp(); p!=null && !p.isLast(); p = p.next()) {
@@ -96,7 +96,7 @@ abstract class Walk<T> {
         }
     }
 
-    static class Follow<Tok extends Token> extends WalkTokenSet<Tok> {
+    static class Follow<Tok extends Input> extends WalkTokenSet<Tok> {
         private final Element me;
         private final HashSet<Element> all;
         private boolean eof = false;
@@ -129,7 +129,7 @@ abstract class Walk<T> {
                 Sequence a = (Sequence)x;
                 Position mp = null;
                 for(Position pos = a.firstp(); pos != null && !pos.isLast(); pos = pos.next()) {
-                    if (matched) cs = cs.union(new First<Tok>(cs.empty(), c).walk(pos.element()));
+                    if (matched) cs = cs.union(c.first(pos.element(), cs.empty()));
                     if (pos.isLast()) { matched = (matched && pos.element().possiblyEpsilon(c)); continue; }
                     boolean good = false;
                     if (e instanceof Atom) {
@@ -170,8 +170,10 @@ abstract class Walk<T> {
         public final HashMap<Element,Boolean> possiblyEpsilon = new HashMap<Element,Boolean>();
         public HashMap<Element,Boolean> eof = new HashMap<Element,Boolean>();
         public HashMap<Element,Topology> follow = new HashMap<Element,Topology>();
-        //public HashMap<Element,HashSet<Element>>  ys            = new HashMap<Element,HashSet<Element>>();
         public HashMapBag<Element,Element>  ys = new HashMapBag<Element,Element>();
         public HashMap<Element,Topology> atoms = new HashMap<Element,Topology>();
+        public <Tok extends Input> Topology<Tok> first(Element e, Topology<Tok> empty) {
+            return new Walk.First<Tok>(empty, this).walk(e);
+        }
     }
 }