diffoscope/diff.py

@@ -278,12 +278,12 @@ def empty_file_feeder():
     return feeder
 
 
-def make_feeder_from_raw_reader(in_file, filter=None):
+def make_feeder_from_raw_reader(in_file, filterfn=None):
     """
     Create a feeder that checksums, truncates, and transcodes the data.  The
-    optional argument FILTER is a callable that gets passed each line, and
+    optional argument filterfn is a callable that gets passed each line, and
     returns the line that should be used in its stead.  (There is no facility
-    for FILTER to discard a line entirely.)
+    for filterfn to discard a line entirely.)
 
     See _Feeder for feeders.
     """
@@ -299,7 +299,7 @@ def make_feeder_from_raw_reader(in_file, filter=None):
 
         for buf in in_file:
             line_count += 1
-            out = filter(buf) if filter else buf
+            out = filterfn(buf) if filterfn else buf
             if h:
                 h.update(out)
             if line_count < max_lines:
@@ -384,7 +384,9 @@ def color_unified_diff(diff):
 
 DIFFON = "\x01"
 DIFFOFF = "\x02"
-MAX_WF_SIZE = 1024  # any higher, and linediff takes >1 second and >200MB RAM
+MAX_WAGNER_FISCHER_SIZE = (
+    1024  # any higher, and linediff takes >1 second and >200MB RAM
+)
 
 
 def _linediff_sane(x):
@@ -404,7 +406,7 @@ def diffinput_truncate(s, sz):
 
 
 def linediff(s, t, diffon, diffoff):
-    # calculate common prefix/suffix, easy optimisation to WF
+    # calculate common prefix/suffix, easy optimisation for Wagner-Fischer
     prefix = os.path.commonprefix((s, t))
     if prefix:
         s = s[len(prefix) :]
@@ -414,9 +416,9 @@ def linediff(s, t, diffon, diffoff):
         s = s[: -len(suffix)]
         t = t[: -len(suffix)]
 
-    # truncate so WF doesn't blow up RAM
-    s = diffinput_truncate(s, MAX_WF_SIZE)
-    t = diffinput_truncate(t, MAX_WF_SIZE)
+    # truncate so Wagner-Fischer doesn't blow up RAM
+    s = diffinput_truncate(s, MAX_WAGNER_FISCHER_SIZE)
+    t = diffinput_truncate(t, MAX_WAGNER_FISCHER_SIZE)
     l1, l2 = zip(*linediff_simplify(linediff_wagnerfischer(s, t)))
 
     def to_string(k, v):
@@ -487,7 +489,7 @@ def linediff_wagnerfischer(s, t):
 
 
 def linediff_simplify(g):
-    """Simplify the output of WF."""
+    """Simplify the output of Wagner-Fischer."""
     current = None
     for l, r in g:
         if not current: