Merge pull request #1980 from 0xGusMcCrae/fast-sim-var-2

Additional optimizations for similar_variables.py

slither/detectors/variables/similar_variables.py

@@ -47,9 +47,7 @@ class SimilarVarsDetection(AbstractDetector):
         Returns:
             bool: true if names are similar
         """
-        if len(seq1) != len(seq2):
-            return False
-        val = difflib.SequenceMatcher(a=seq1.lower(), b=seq2.lower()).ratio()
+        val = difflib.SequenceMatcher(a=seq1, b=seq2).ratio()
         ret = val > 0.90
         return ret
 
@@ -67,19 +65,21 @@ class SimilarVarsDetection(AbstractDetector):
 
         all_var = list(set(all_var + contract_var))
 
-        ret = []
+        ret = set()
         # pylint: disable=consider-using-enumerate
         for i in range(len(all_var)):
             v1 = all_var[i]
             _v1_name_lower = v1.name.lower()
             for j in range(i, len(all_var)):
                 v2 = all_var[j]
-                if _v1_name_lower != v2.name.lower():
-                    if SimilarVarsDetection.similar(v1.name, v2.name):
-                        if (v2, v1) not in ret:
-                            ret.append((v1, v2))
+                if len(v1.name) != len(v2.name):
+                    continue
+                _v2_name_lower = v2.name.lower()
+                if _v1_name_lower != _v2_name_lower:
+                    if SimilarVarsDetection.similar(_v1_name_lower, _v2_name_lower):
+                        ret.add((v1, v2))
 
-        return set(ret)
+        return ret
 
     def _detect(self) -> List[Output]:
         """Detect similar variables name