consistent name N for input length, update example

README.md

@@ -118,7 +118,7 @@ emit MIL0001781108.xls            \
    | sep                          \
   ]                               \
   | pack 10                       \
-  | sub dec:ev:n                  \
+  | blockop --dec -sN B-S         \
 ]]                                \
 | dump payload.ps1
 ```

refinery/lib/argformats.py

@@ -634,7 +634,7 @@ class DelayedNumbinArgument(DelayedArgument):
     defined here.
     """
 
-    _EV_PARSER = PythonExpression('n')
+    _EV_PARSER = PythonExpression('N')
 
     def _mbin(self, expr: str) -> bytes:
         binary = multibin(expr)
@@ -669,14 +669,14 @@ def handler(self, expression: str) -> Iterable[int]:
     def ev(self, expression: str) -> Iterable[int]:
         """
         Final modifier `ev:expression`; uses a `refinery.lib.argformats.PythonExpression`
-        parser to process expressions that may contain the variable `n` whose value will be
+        parser to process expressions that may contain the variable `N` whose value will be
         the size of the input data.
         """
         ev = self._EV_PARSER(expression)
         try:
             return self._iter(ev())
         except Exception:
-            return lambda d: self._iter(ev(n=len(d)))
+            return lambda d: self._iter(ev(N=len(d)))
 
     @handler.register('unpack', final=True)
     def unpack(self, expression: str) -> Iterable[int]:

test/lib/test_frame.py

@@ -50,7 +50,7 @@ def test_documentation_example_04(self):
     def test_real_world_01(self):
         encoded = B'''301815214850156721331018480063340936214488055910529404970112631124608113197561534315323106291311611118111571030916590053421252410301171850583912575068111856414554157930507606789054031912510227182600807906431133491248306004123002146510940169690710820141169320955312014120171102115059068660995810412198261688106236171480925510919175470806111215112451580216678065680593716920140350943309471097820618705622181381760512207200740695112292051860572813684059730540612867133770664415988405914129061377506879064041396607792051271161313019124720712811569074680757406931112780654609788055291148605702141810628505815128490945608789054940492611748095590847706617126221215309060083411027606705138001434509852091211222411908135111322312025118181250314030113440993311087056570868006343100341090114209134640795408939104470969005365078580853510871072121313211155088071361612710133620813710651092820619305073070401034210170073610823810550093830603610763080201236707691052400143051380813527116720712411948095460972511826117830604909480063550881313020123700732911434109111327107252091820612112243100171263111266077191245908460083860575009354089740698805569074161279005364079321115309035108401031812509134770666308092051560874210137106680758405975068670761013351092730709105236107381053311058085141294409981062930500713676067850583910402141121311512865078790647806541102620815708606137890546108294049031402811547096011424509822121301130413987056231204'''
         decoded = B'''wMIc  'prOcess'   "cALl"  crEAtE   "powErsHell  -NoNiNtErAC -NoPrOFi -WIn 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000'''
-        pl = r.chop(476) [ r.chop(5, '-t') [ r.sorted | r.snip('2:') | r.sep ]| r.pack(10) | r.blockop('--ctr', 'B+S-A', 'ev:n') ] # noqa
+        pl = r.chop(476) [ r.chop(5, '-t') [ r.sorted | r.snip('2:') | r.sep ]| r.pack(10) | r.blockop('--dec', '-sN', 'B-S') ] # noqa
         self.assertEqual(decoded, pl(encoded))
 
     def test_nonblocking(self):

test/units/blockwise/test_arithmetic_units.py

@@ -31,7 +31,7 @@ def test_handler_unpack_03(self):
         self.assertEqual(add(bytes(12)), B'\x00\xBE\xEF' * 4)
 
     def test_handler_ev(self):
-        xor = refinery.xor('ev:n,0xB0,0x12')
+        xor = refinery.xor('ev:N,0xB0,0x12')
         self.assertEqual(xor(bytes(0x54)), 28 * B'\x54\xB0\x12')
 
     def test_argument_reset(self):

test/units/test_grabbag.py

@@ -7,6 +7,7 @@
 
 from refinery import (
     aes,
+    blockop,
     carve_b64z,
     cca,
     chop,
@@ -20,7 +21,6 @@
     sep,
     snip,
     sorted,
-    sub,
     xlxtr,
     xtp,
 )
@@ -34,7 +34,7 @@ def test_example_01_maldoc(self):
         pipeline = xlxtr('9.5:11.5', '15.15', '12.5:14.5') [
             scope('-n', 3) | chop('-t', 5) [
                 sorted | snip('2:') | sep
-            ] | pack(10) | sub('dec:ev:n')
+            ] | pack(10) | blockop('--dec', '-sN', 'B-S')
         ] | carve_b64z | deob_ps1 | carve_b64z | deob_ps1 | xtp('domain', filter=True)
 
         with BytesIO(data) as sample: