Previous to this patch the printing mechanism was a bit of a tangled
mess. This patch attempts to consolidate printing into one interface.
All (non-debug) printing now uses the mp_print* family of functions,
mainly mp_printf. All these functions take an mp_print_t structure as
their first argument, and this structure defines the printing backend
through the "print_strn" function of said structure.
Printing from the uPy core can reach the platform-defined print code via
two paths: either through mp_sys_stdout_obj (defined pert port) in
conjunction with mp_stream_write; or through the mp_plat_print structure
which uses the MP_PLAT_PRINT_STRN macro to define how string are printed
on the platform. The former is only used when MICROPY_PY_IO is defined.
With this new scheme printing is generally more efficient (less layers
to go through, less arguments to pass), and, given an mp_print_t*
structure, one can call mp_print_str for efficiency instead of
mp_printf("%s", ...). Code size is also reduced by around 200 bytes on
Thumb2 archs.
Previous to this patch, a big-int, float or imag constant was interned
(made into a qstr) and then parsed at runtime to create an object each
time it was needed. This is wasteful in RAM and not efficient. Now,
these constants are parsed straight away in the parser and turned into
objects. This allows constants with large numbers of digits (so
addresses issue #1103) and takes us a step closer to #722.
With this patch str/bytes construction is streamlined. Always use a
vstr to build a str/bytes object. If the size is known beforehand then
use vstr_init_len to allocate only required memory. Otherwise use
vstr_init and the vstr will grow as needed. Then use
mp_obj_new_str_from_vstr to create a str/bytes object using the vstr
memory.
Saves code ROM: 68 bytes on stmhal, 108 bytes on bare-arm, and 336 bytes
on unix x64.
This fixes conversion when float type has more mantissa bits than small int,
and float value has small exponent. This is for example the case of 32-bit
platform using doubles, and converting value of time.time(). Conversion of
floats with larg exponnet is still not handled correctly.
mp_obj_int_get_truncated is used as a "fast path" int accessor that
doesn't check for overflow and returns the int truncated to the machine
word size, ie mp_int_t.
Use mp_obj_int_get_truncated to fix struct.pack when packing maximum word
sized values.
Addresses issues #779 and #998.
Multiplication of a tuple, list, str or bytes now yields an empty
sequence (instead of crashing). Addresses issue #799
Also added ability to mult bytes on LHS by integer.
Damien George
David Steinberg
Paul Sokolovsky
Dave Hylands