add exact match

textgen_evaluator.py

@@ -52,6 +52,8 @@ Scores are calculated for individual translated segments—generally sentences
 Those scores are then averaged over the whole corpus to reach an estimate of the translation's overall quality.
 Neither intelligibility nor grammatical correctness are not taken into account.
 
+EXACT MATCH: Returns the rate at which the input predicted strings exactly match their references, ignoring any strings input as part of the regexes_to_ignore list.
+
 """
 
 _KWARGS_DESCRIPTION = """
@@ -76,6 +78,9 @@ BLEU:{
     'length_ratio': ratio of lengths,
     'translation_length': translation_length,
     'reference_length': reference_length
+},
+EXACT_MATCH:{
+    "exact_match": exact_match rate. Possible values are between 0.0 and 1.0, inclusive.
 }
 """
 
@@ -104,12 +109,18 @@ class TextGenEvaluator(evaluate.Metric):
 
         rouge_score = evaluate.load("rouge")
 
-        scores = rouge_score.compute(
+        rouge_results = rouge_score.compute(
             predictions=predictions, references=references
         )
         bleu_score = evaluate.load("bleu")
-        results = bleu_score.compute(
+        bleu_results = bleu_score.compute(
+            predictions=predictions, references=references
+        )
+        
+        exact_match_score = evaluate.load("exact_match")
+        exact_match_results = exact_match_score.compute(
             predictions=predictions, references=references
         )
+        
 
-        return {"ROUGE": scores, "BLEU": results}
+        return {"ROUGE": rouge_results, "BLEU": bleu_results, "EXACT_MATCH": exact_match_results}