Issue was with uPy: on local machine with micropython-lib installed, io
module is available. Not the case on Travis CI, where only _io module
is available in uPy.
This patch adds a configuration option (MICROPY_CAN_OVERRIDE_BUILTINS)
which, when enabled, allows to override all names within the builtins
module. A builtins override dict is created the first time the user
assigns to a name in the builtins model, and then that dict is searched
first on subsequent lookups. Note that this implementation doesn't
allow deleting of names.
This patch also does some refactoring of builtins code, creating the
modbuiltins.c file.
Addresses issue #959.
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.
Behaviour of array initialisation is subtly different for bytes,
bytearray and array.array when argument has buffer protocol. This patch
gets us CPython conformant (except we allow initialisation of
array.array by buffer with length not a multiple of typecode).
Eg b"123" + bytearray(2) now works. This patch actually decreases code
size while adding functionality: 32-bit unix down by 128 bytes, stmhal
down by 84 bytes.
gc.enable/disable are now the same as CPython: they just control whether
automatic garbage collection is enabled or not. If disabled, you can
still allocate heap memory, and initiate a manual collection.
Before, sizeof() could be applied to a structure field only if that field
was itself a structure. Now it can be applied to PTR and ARRAY fields too.
It's not possible to apply it to scalar fields though, because as soon as
scalar field (int or float) is dereferenced, its value is converted into
Python int/float value, and all original type info is lost. Moreover, we
allow sizeof of type definitions too, and there int is used to represent
(scalar) types. So, we have ambiguity what int may be - either dereferenced
scalar structure field, or encoded scalar type. So, rather throw an error
if user tries to apply sizeof() to int.
UART object now uses a stream-like interface: read, readall, readline,
readinto, readchar, write, writechar.
Timeouts are configured when the UART object is initialised, using
timeout and timeout_char keyword args.
The object includes optional read buffering, using interrupts. You can set
the buffer size dynamically using read_buf_len keyword arg. A size of 0
disables buffering.
mode argument is used to assert it works
encoding argument is used to make sure CPython uses the correct encoding
as it does not automatically use utf-8
Also, usocket.readinto(). Known issue is that .readinto() should be available
only for binary files, but micropython uses single method table for both
binary and text files.
