ud.FixCompoundName: If a treebank connects person names using compound, convert it to flat:name.

Author: dan-zeman

udapi/block/ud/fixcompoundname.py

@@ -0,0 +1,36 @@
+"""
+Block ud.FixCompoundName finds compound relations between PROPN nodes and converts
+them to flat:name. This is not necessarily correct in all situations. The difference
+between compound and flat is that compound allows to distinguish head and modifier.
+Multiword person names (given name and surname, or various other patterns) typically
+should be analyzed as flat but there are treebanks that incorrectly use compound
+for person names. This block can be used to fix them.
+"""
+from udapi.core.block import Block
+import logging
+
+
+class FixCompoundName(Block):
+    """
+    Converts a compound relation between two PROPN nodes into a flat relation.
+    Compounds of a PROPN and a non-PROPN will be left alone, although they are
+    suspicious, too.
+    """
+
+    def process_node(self, node):
+        if node.upos == 'PROPN' and node.udeprel == 'compound' and node.parent.upos == 'PROPN':
+            # See if there are other PROPN compound siblings.
+            namewords = [x for x in node.siblings if x.upos == 'PROPN' and x.udeprel == 'compound']
+            namewords.append(node.parent)
+            namewords = sorted(namewords, key=lambda x: x.ord)
+            ###!!! We currently cannot transform enhanced dependencies.
+            ###!!! If we proceed, the basic tree would diverge from the enhanced dependencies.
+            if len(node.deps) > 0:
+                logging.fatal('There are enhanced dependencies but ud.FixCompoundName has been implemented only for basic dependencies.')
+            # The first name word will be the technical head. If it is the current parent, fine.
+            if namewords[0] != node.parent:
+                namewords[0].parent = node.parent.parent
+                namewords[0].deprel = node.parent.deprel
+            for i in range(len(namewords)-1):
+                namewords[i+1].parent = namewords[0]
+                namewords[i+1].deprel = 'flat:name'