With this patch all illegal assignments are reported as "can't assign to
expression". Before the patch there were special cases for a literal on
the LHS, and for augmented assignments (eg +=), but it seems a waste of
bytes (and there are lots of bytes used in error messages) to spend on
distinguishing such errors which a user will rarely encounter.
By removing the 'E' code from the operator token encoding mini-language the
tokenising can be simplified. The 'E' code was only used for the !=
operator which is now handled as a special case; the optimisations for the
general case more than make up for the addition of this single, special
case. Furthermore, the . and ... operators can be handled in the same way
as != which reduces the code size a little further.
This simplification also removes a "goto".
Changes in code size for this patch are (measured in bytes):
bare-arm: -48
minimal x86: -64
unix x86-64: -112
unix nanbox: -64
stmhal: -48
cc3200: -48
esp8266: -76
The self variable may be closed-over in the function, and in that case the
call to super() should load the contents of the closure cell using
LOAD_DEREF (before this patch it would just load the cell directly).