checkpoint

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

diff --git a/src/edu/berkeley/sbp/Union.java b/src/edu/berkeley/sbp/Union.java
index dce9cbe..484616d 100644 (file)
--- a/src/edu/berkeley/sbp/Union.java
+++ b/src/edu/berkeley/sbp/Union.java
@@ -10,6 +10,10 @@ import java.lang.ref.*;
 /** an element which can produce one of several alternatives */
 public class Union extends Element implements Iterable<Sequence> {
 
+    private final String name;
+    private final boolean synthetic;
+    private final List<Sequence> alternatives = new ArrayList<Sequence>();
+
     /**
      *  Since every cycle in a non-degenerate grammar contains at
      *  least one Union, every instance of this class must be able to
@@ -19,16 +23,13 @@ public class Union extends Element implements Iterable<Sequence> {
      *  @param shortForm the "short form" display; usually 
      *  @param synthetic if true, this Union's "long form" is "obvious" and should not be displayed when printing the grammar
      */
-    public Union(String shortForm) { this(shortForm, false); }
-    public Union(String shortForm, boolean synthetic) {
-        this.shortForm = shortForm;
+    public Union() { this(null, false); }
+    public Union(String name) { this(name, false); }
+    public Union(String name, boolean synthetic) {
+        this.name = name;
         this.synthetic = synthetic;
     }
 
-    final String shortForm;
-    final boolean synthetic;
-    private final List<Sequence> alternatives = new ArrayList<Sequence>();
-
     public Iterator<Sequence> iterator() { return alternatives.iterator(); }
     public boolean contains(Sequence s) { return alternatives.contains(s); }
 
@@ -44,14 +45,10 @@ public class Union extends Element implements Iterable<Sequence> {
     // Epsilon Form //////////////////////////////////////////////////////////////////////////////
 
     // FIXME
-    public static Union epsilon = new Union("()");
-    static { epsilon.add(Sequence.empty); }
-
-    // FIXME
-    private Forest.Ref epsilonForm = null;
+    private Forest.Many epsilonForm = null;
     Forest epsilonForm() {
         if (epsilonForm != null) return epsilonForm;
-        epsilonForm = new Forest.Ref();
+        epsilonForm = new Forest.Many();
         for(Sequence s : this) {
             // FIXME FIXME FIXME
             if (new Walk.Cache().possiblyEpsilon(s))
@@ -62,21 +59,42 @@ public class Union extends Element implements Iterable<Sequence> {
 
     // Display //////////////////////////////////////////////////////////////////////////////
 
-    public String toString() { return shortForm; }
+    public String getName() {
+        if (name != null) return name;
+        return "(anon_union)";
+    }
+    public String toString() {
+        if (name != null) return name;
+        StringBuffer sb = new StringBuffer();
+        sb.append("(");
+        bodyToString(sb, "", " | ");
+        sb.append(")");
+        return sb.toString();
+    }
     public StringBuffer toString(StringBuffer sb) {
         if (synthetic) return sb;
         boolean first = true;
+        String before = StringUtil.pad(15, getName()) + " = ";
         if (alternatives.size()==0) {
-            sb.append(StringUtil.pad(15, shortForm) + " = ");
-        } else for(Sequence s : this) {
+            sb.append(before);
+        } else {
+            bodyToString(sb,
+                         before,
+                         "\n" + StringUtil.pad(15, "")        + " | ");
+            sb.append('\n');
+        }
+        return sb;
+    }
+    
+    private void bodyToString(StringBuffer sb, String before, String between) {
+        boolean first = true;
+        for(Sequence s : this) {
+            if (s.lame) continue;
             // FIXME: what to do here about printing out negated sequences?
-            sb.append(StringUtil.pad(15, first ? shortForm : "") + (first ? " = " : "  | "));
+            sb.append(first ? before : between);
             first = false;
             sb.append(s.toString());
-            sb.append('\n');
         }
-        sb.append('\n');
-        return sb;
     }
 
 }