This ought to fix one tree in PTB3.... weirdly it changes several others

Author: AngledLuffa

src/edu/stanford/nlp/trees/CoordinationTransformer.java

@@ -164,7 +164,10 @@ public Tree transformTree(Tree t) {
     if (VERBOSE) {
       debugLine("After rearrangeNowThat:           ", t);
     }
-
+    t = mergeYodaVerbs(t);
+    if (VERBOSE) {
+      debugLine("After mergeYodaVerbs:             ", t);
+    }
     return t;
   }
 
@@ -182,6 +185,19 @@ private static Tree rearrangeNowThat(Tree t) {
   }
 
 
+  private static final TregexPattern mergeYodaVerbsTregex =
+    TregexPattern.compile("VP=home < VBN=vbn $+ (VP=willbe <... {(__=will < will|have|has) ; (VP < (__=be << be|been))})");
+
+  private static final TsurgeonPattern mergeYodaVerbsTsurgeon =
+    Tsurgeon.parseOperation("[createSubtree VP vbn] [move will >-1 home] [move be >-1 home] [prune willbe]");
+
+  private static Tree mergeYodaVerbs(Tree t) {
+    if (t == null) {
+      return t;
+    }
+    return Tsurgeon.processPattern(mergeYodaVerbsTregex, mergeYodaVerbsTsurgeon, t);
+  }
+
   private static final TregexPattern changeSbarToPPTregex =
     TregexPattern.compile("NP < (NP $++ (SBAR=sbar < (IN < /^(?i:after|before|until|since|during)$/ $++ S)))");