With the implementation of proper string formatting, code to print a
small int was delegated to mpz_as_str_inpl (after first converting the
small int to an mpz using stack memory). But mpz_as_str_inpl allocates
heap memory to do the conversion, so small ints needed heap memory just
to be printed.
This fix has a separate function to print small ints, which does not
allocate heap, and allocates less stack.
String formatting, printf and pfenv are now large beasts, with some
semi-duplicated code.
These two are apprerently the most concise and efficient way to convert
int to/from bytes in Python. The alternatives are struct and array modules,
but methods using them are more verbose in Python code and less efficient
in memory/cycles.
Full CPython compatibility with this requires actually parsing the
input so far collected, and if it fails parsing due to lack of tokens,
then continue collecting input. It's not worth doing it this way. Not
having compatibility at this level does not hurt the goals of Micro
Python.
stmhal relies on pfenv_* to implement its printf. Thus, it needs a
pfenv_print_int which prints a proper 32-bit integer. With latest
change to pfenv, this function became one that took mp_obj_t, and
extracted the integer value from that object.
To fix temporarily, pfenv_print_int has been renamed to
pfenv_print_mp_int (to indicate it takes a mp_obj_t for the int), and
pfenv_print_int has been added (which takes a normal C int). Currently,
pfenv_print_int proxies to pfenv_print_mp_int, but this means it looses
the MSB. Need to find a way to fix this, but the only way I can think
of will duplicate lots of code.
Two things: 1) set flags in copy properly; make mp_map_init() not be too
smart and do something with requested alloc size. Policy of using prime
numbers for alloc size is high-level policy which should be applied at
corresponding high levels. Low-level functions should just do what they're
asked to, because they don't have enough context to be smarter than that.
For example, munging with alloc size of course breaks dict copying (as
changing sizes requires rehashing).
Based on the discussion in #433. mp_load_attr() is critical-path function,
so any extra check will slowdown any script. As supporting default val
required only for getattr() builtin, move correspending implementation
there (still as a separate function due to concerns of maintainability
of such almost-duplicated code instances).
This is to reduce ROM usage. stream_p is used in file and socket types
only (at the moment), so seems a good idea to make the protocol
functions a pointer instead of the actual structure.
It saves 308 bytes of ROM in the stmhal/ port, 928 in unix/.
Finishes addressing issue #424.
In the end this was a very neat refactor that now makes things a lot
more consistent across the py code base. It allowed some
simplifications in certain places, now that everything is a dict object.
Also converted builtins tables to dictionaries. This will be useful
when we need to turn builtins into a proper module.
Damien George
Paul Sokolovsky
Andrew Scheller
Dave Hylands