Add '%b' as a valid percent-format (PEP 461).

Issue #125.

Author: vpetrovykh

grammars/MagicPython.cson

@@ -925,7 +925,7 @@ repository:
             [-+#0 ]*
             (\\d+|\\*)? (\\.(\\d+|\\*))?
             ([hlL])?
-            [diouxXeEfFgGcrsa%]
+            [diouxXeEfFgGcrsab%]
         )
       
     '''

grammars/MagicPython.tmLanguage

@@ -1419,7 +1419,7 @@
       [-+#0 ]*
       (\d+|\*)? (\.(\d+|\*))?
       ([hlL])?
-      [diouxXeEfFgGcrsa%]
+      [diouxXeEfFgGcrsab%]
   )
 </string>
         <key>captures</key>

grammars/src/MagicPython.syntax.yaml

@@ -777,7 +777,7 @@ repository:
             [-+#0 ]*
             (\d+|\*)? (\.(\d+|\*))?
             ([hlL])?
-            [diouxXeEfFgGcrsa%]
+            [diouxXeEfFgGcrsab%]
         )
     captures:
       '1': {name: constant.character.format.placeholder.other.python}

test/strings/format16.py

@@ -0,0 +1,19 @@
+a = b'%b' % b'foo'
+
+
+
+a             : source.python
+              : source.python
+=             : keyword.operator.assignment.python, source.python
+              : source.python
+b             : source.python, storage.type.string.python, string.quoted.binary.single.python
+'             : punctuation.definition.string.begin.python, source.python, string.quoted.binary.single.python
+%b            : constant.character.format.placeholder.other.python, meta.format.percent.python, source.python, string.quoted.binary.single.python
+'             : punctuation.definition.string.end.python, source.python, string.quoted.binary.single.python
+              : source.python
+%             : keyword.operator.arithmetic.python, source.python
+              : source.python
+b             : source.python, storage.type.string.python, string.quoted.binary.single.python
+'             : punctuation.definition.string.begin.python, source.python, string.quoted.binary.single.python
+foo           : source.python, string.quoted.binary.single.python
+'             : punctuation.definition.string.end.python, source.python, string.quoted.binary.single.python