[refactor] Use regex indices directly

builtin/func_eggex.py

@@ -29,14 +29,15 @@ def Call(self, rd):
         # TODO: Support strings for named captures
         i = rd.OptionalInt(default_=0)
 
-        groups = self.mem.RegexGroups()
-        num_groups = len(groups)  # including group 0
+        s, indices = self.mem.GetRegexIndices()
+        num_groups = len(indices) / 2  # including group 0
         if i < num_groups:
-            captured = groups[i]
-            if captured is None:
+            start = indices[2 * i]
+            end = indices[2 * i + 1]
+            if start == -1:
                 return value.Null
             else:
-                return value.Str(captured)
+                return value.Str(s[start:end])
         else:
             if num_groups == 0:
                 msg = 'No regex capture groups'

core/state.py

@@ -1821,7 +1821,9 @@ def GetValue(self, name, which_scopes=scope_e.Shopt):
             return value.List(items)
 
         if name == 'BASH_REMATCH':
-            return value.BashArray(self.RegexGroups())
+            groups = util.RegexGroups(self.regex_string[-1],
+                                      self.regex_indices[-1])
+            return value.BashArray(groups)
 
         # Do lookup of system globals before looking at user variables.  Note: we
         # could optimize this at compile-time like $?.  That would break
@@ -2158,9 +2160,9 @@ def SetRegexIndices(self, s, indices):
         self.regex_string[-1] = s
         self.regex_indices[-1] = indices
 
-    def RegexGroups(self):
-        # type: () -> List[Optional[str]]
-        return util.RegexGroups(self.regex_string[-1], self.regex_indices[-1])
+    def GetRegexIndices(self):
+        # type: () -> Tuple[str, List[int]]
+        return self.regex_string[-1], self.regex_indices[-1]
 
 
 #

core/util.py

@@ -20,10 +20,7 @@
 
 
 def RegexGroups(s, indices):
-    # type: (str, Optional[List[int]]) -> List[str]
-    if indices is None:
-        return None
-
+    # type: (str, List[int]) -> List[str]
     groups = []  # type: List[str]
     n = len(indices)
     for i in xrange(n / 2):
@@ -40,6 +37,8 @@ def simple_regex_search(pat, s):
     # type: (str, str) -> List[str]
     """Convenience wrapper around libc."""
     indices = libc.regex_search(pat, 0, s)
+    if indices is None:
+        return None
     return RegexGroups(s, indices)