Highlight ++ and -- as illegals

Author: 1st1

grammars/MagicPython.cson

@@ -1684,7 +1684,7 @@ repository:
     patterns: [
       {
         name: "invalid.illegal.operator.python"
-        match: "&&|\\|\\|"
+        match: "&&|\\|\\||--|\\+\\+"
       }
       {
         name: "invalid.illegal.operator.python"

grammars/MagicPython.tmLanguage

@@ -2652,7 +2652,7 @@ indirectly through syntactic constructs
             <key>name</key>
             <string>invalid.illegal.operator.python</string>
             <key>match</key>
-            <string>&amp;&amp;|\|\|</string>
+            <string>&amp;&amp;|\|\||--|\+\+</string>
           </dict>
           <dict>
             <key>name</key>

grammars/src/MagicPython.syntax.yaml

@@ -1154,7 +1154,7 @@ repository:
   illegal-operator:
     patterns:
       - name: invalid.illegal.operator.python
-        match: '&&|\|\|'
+        match: '&&|\|\||--|\+\+'
       - name: invalid.illegal.operator.python
         match: '[?$]'
       - name: invalid.illegal.operator.python

test/expressions/expr17.py

@@ -0,0 +1,29 @@
+a++
+b--
+++a
+--b
+a++c
+c--b
+a(--a)
+
+
+
+a             : source.python
+++            : invalid.illegal.operator.python, source.python
+b             : source.python
+--            : invalid.illegal.operator.python, source.python
+++            : invalid.illegal.operator.python, source.python
+a             : source.python
+--            : invalid.illegal.operator.python, source.python
+b             : source.python
+a             : source.python
+++            : invalid.illegal.operator.python, source.python
+c             : source.python
+c             : source.python
+--            : invalid.illegal.operator.python, source.python
+b             : source.python
+a             : meta.function-call.generic.python, meta.function-call.python, source.python
+(             : meta.function-call.python, punctuation.definition.arguments.begin.python, source.python
+--            : invalid.illegal.operator.python, meta.function-call.arguments.python, meta.function-call.python, source.python
+a             : meta.function-call.arguments.python, meta.function-call.python, source.python
+)             : meta.function-call.python, punctuation.definition.arguments.end.python, source.python