Resolve "Structure View Support"

Closes #3 (closed)

src/main/grammar/Aspect.bnf

@@ -128,7 +128,7 @@ aspect_inh_attribute_declaration ::= annotation* INH NTA? LAZY? FINAL? aspect_ty
 }
 
 // FIXME parentheses are not required around the WHEN expression?
-aspect_rewrite ::= REWRITE aspect_name (ast_type_name DOT method_name LPAREN RPAREN)? LBRACE ((WHEN LPAREN expression RPAREN)? TO aspect_type ( expression SEMICOLON | block ))+ RBRACE
+aspect_rewrite ::= REWRITE ast_type_name (ast_type_name DOT method_name LPAREN RPAREN)? LBRACE ((WHEN LPAREN expression RPAREN)? TO aspect_type ( expression SEMICOLON | block ))+ RBRACE
 
 aspect_syn_equation ::= annotation* EQUATION ast_type_name DOT attribute_name LPAREN (type parameter_name (COMMA type parameter_name)*)? RPAREN ( ASSIGN expression SEMICOLON | block )