mp_module_obj_t can now be put in ROM.
Configuration of float type is now similar to longint: can now choose
none, float or double as the implementation.
math module has basic math functions. For STM port, these are not yet
implemented (they are just stub functions).
Each built-in exception is now a type, with base type BaseException.
C exceptions are created by passing a pointer to the exception type to
make an instance of. When raising an exception from the VM, an
instance is created automatically if an exception type is raised (as
opposed to an exception instance).
Exception matching (RT_BINARY_OP_EXCEPTION_MATCH) is now proper.
Handling of parse error changed to match new exceptions.
mp_const_type renamed to mp_type_type for consistency.
Ultimately all static strings should be qstr. This entry in the type
structure is only used for printing error messages (to tell the type of
the bad argument), and printing objects that don't supply a .print method.
Unlike CPython socket, microsocket object already implements stream protocol
(read/write methods), so makefile() just returns object itself. TODO: this
doesn't take care of arguments CPython's makefile() may accept.
TODO: Decide if we really need separate bytecode for creating functions
with default arguments - we would need same for closures, then there're
keywords arguments too. Having all combinations is a small exponential
explosion, likely we need just 2 cases - simplest (no defaults, no kw),
and full - defaults & kw.
We still have FAST_[0,1,2] byte codes, but they now just access the
fastn array (before they had special local variables). It's now
simpler, a bit faster, and uses a bit less stack space (on STM at least,
which is most important).
The only reason now to keep FAST_[0,1,2] byte codes is for compressed
byte code size.
In Python, importing module several times returns same underlying module
object. This also fixes import statement handling for builtin modules.
There're still issues:
1. CPython exposes set of loaded modules as sys.modules, we may want to
do that either.
2. Builtin modules are implicitly imported, which is not really correct.
We should separate registering a (builtin) module and importing a module.
CPython keeps builtin module names in sys.builtin_module_names .
