Fix the output of optional CoordinationPatterns in Tregex

Author: AngledLuffa

src/edu/stanford/nlp/trees/tregex/CoordinationPattern.java

@@ -45,10 +45,13 @@ public String toString() {
       if (isNegated()) {
         sb.append("!(");
       }
+      if (isOptional()) {
+        sb.append("?(");
+      }
       for (TregexPattern node : children) {
         sb.append(node.toString());
       }
-      if (isNegated()) {
+      if (isNegated() || isOptional()) {
         sb.append(")");
       }
     } else {

src/edu/stanford/nlp/trees/tregex/DescriptionPattern.java

@@ -266,6 +266,8 @@ public String toString() {
       sb.append('=');
       sb.append(name);
     }
+    // TODO: is this space necessary?  The CoordinationPattern could put spaces between terms
+    // Currently this results in extra blank spaces at the end of a pattern
     sb.append(' ');
     if (child != null) {
       sb.append(child.toString());

test/src/edu/stanford/nlp/trees/tregex/TregexTest.java

@@ -1559,6 +1559,15 @@ public void testNegatedOptional() {
     }
   }
 
+  public void testOptionalToString() {
+    TregexPattern pattern;
+    pattern = TregexPattern.compile("A ?(< B < C)");
+    assertEquals("Root (A ?(< B < C ))", pattern.toString());
+
+    pattern = TregexPattern.compile("A ?< B");
+    assertEquals("Root (A ?< B )", pattern.toString());
+  }
+
   /**
    * A user supplied an example of a negated disjunction which went into an infinite loop.
    * Apparently no one had ever used a negated disjunction of tree structures before!