Single variable cannot have many values of different types. This also saves some memory, because union allocates memory just for one of its members.

Every modern hardware, including embedded devices, should support floating point numbers.

This also fixes line number on OP_CLASS_INIT and OP_INTERFACE_INIT.

Whole configuration should be done in config file.

It was not fully implemented and such feature should be implemented in separate module or on developers own.

Errors are used only internally to emit notifications about compilation/execution problems. They should not be catched and handled by custom handlers, but properly configured (to be displayed or logged). Instead developers should
use exceptions that can be catched with try-catch block.