Assign slice expressions

src/Language/Python/Syntax.hs

@@ -40,6 +40,7 @@ type Syntax =
    , Expression.Bitwise
    , Expression.Call
    , Expression.Comparison
+   , Expression.Enumeration
    , Expression.ScopeResolution
    , Expression.MemberAccess
    , Expression.Subscript
@@ -163,6 +164,7 @@ expression =  argument
           <|> memberAccess
           <|> notOperator
           <|> parameter
+          <|> slice
           <|> subscript
           <|> statement
           <|> tuple
@@ -419,6 +421,13 @@ memberAccess = makeTerm <$> symbol Attribute <*> children (Expression.MemberAcce
 subscript :: Assignment
 subscript = makeTerm <$> symbol Subscript <*> children (Expression.Subscript <$> expression <*> many expression)
 
+slice :: Assignment
+slice = makeTerm <$> symbol Slice <*> children
+  (toEnumeration <$> ((emptyTerm <* symbol AnonColon <* source) <|> (expression <* symbol AnonColon <* source))
+                 <*> ((emptyTerm <* symbol AnonColon <* source) <|> (expression <* symbol AnonColon <* source) <|> (expression <|> emptyTerm))
+                 <*> (expression <|> emptyTerm))
+  where toEnumeration start stop step = Expression.Enumeration start stop step
+
 call :: Assignment
 call = makeTerm <$> symbol Call <*> children (Expression.Call <$> identifier <*> (symbol ArgumentList *> children (many expression)
                                                                                 <|> some comprehension))