Apply biaffine decoding before sequence labeling

This ensures that sequence label decoders such as TdzLemma have access
to dependency labels.

(cherry picked from commit 083c1b1)

Author: danieldk

CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## [Unreleased]
+
+### Fixed
+
+- Apply biaffine dependency encoding before sequence labeling, so that
+  the TüBa-D/Z lemma decoder has access to dependency relations.
+
 ## 0.3.0
 
 ### Added

syntaxdot/src/tagger/mod.rs

@@ -62,15 +62,18 @@ impl Tagger {
             predictions.biaffine_score_logits.is_some(),
         );
 
-        self.decode_sequence_labels(sentences, predictions.sequences_top_k)?;
-
+        // Decode dependencies before sequence labels. Biaffine parsing does not require any
+        // other annotations. Sequence labelers, however, may require dependencies (e.g. the
+        // TüBa-D/Z lemmatizer).
         if let (Some(encoder), Some(biaffine_score_logits)) = (
             self.biaffine_encoder.as_ref(),
             predictions.biaffine_score_logits,
         ) {
             tch::no_grad(|| self.decode_biaffine(encoder, sentences, biaffine_score_logits))?
         }
 
+        self.decode_sequence_labels(sentences, predictions.sequences_top_k)?;
+
         Ok(())
     }