[3.5] bpo-26213: Document _UNPACK bytecodes and BUILD_MAP changes by brettcannon · Pull Request #441 · python/cpython
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@@ -765,8 +765,59 @@ the more significant byte last.
.. opcode:: BUILD_MAP (count)
Pushes a new dictionary object onto the stack. The dictionary is pre-sized to hold *count* entries. Pushes a new dictionary object onto the stack. Pops ``2 * count`` items so that the dictionary holds *count* entries: ``{..., TOS3: TOS2, TOS1: TOS}``.
.. versionchanged:: 3.5 The dictionary is created from stack items instead of creating an empty dictionary pre-sized to hold *count* items.
.. opcode:: BUILD_TUPLE_UNPACK (count)
Pops *count* iterables from the stack, joins them in a single tuple, and pushes the result. Implements iterable unpacking in tuple displays ``(*x, *y, *z)``.
.. versionadded:: 3.5
.. opcode:: BUILD_LIST_UNPACK (count)
This is similar to :opcode:`BUILD_TUPLE_UNPACK`, but pushes a list instead of tuple. Implements iterable unpacking in list displays ``[*x, *y, *z]``.
.. versionadded:: 3.5
.. opcode:: BUILD_SET_UNPACK (count)
This is similar to :opcode:`BUILD_TUPLE_UNPACK`, but pushes a set instead of tuple. Implements iterable unpacking in set displays ``{*x, *y, *z}``.
.. versionadded:: 3.5
.. opcode:: BUILD_MAP_UNPACK (count)
Pops *count* mappings from the stack, merges them into a single dictionary, and pushes the result. Implements dictionary unpacking in dictionary displays ``{**x, **y, **z}``.
.. versionadded:: 3.5
.. opcode:: BUILD_MAP_UNPACK_WITH_CALL (oparg)
This is similar to :opcode:`BUILD_MAP_UNPACK`, but is used for ``f(**x, **y, **z)`` call syntax. The lowest byte of *oparg* is the count of mappings, the relative position of the corresponding callable ``f`` is encoded in the second byte of *oparg*.
.. versionadded:: 3.5
.. opcode:: LOAD_ATTR (namei) Expand Down
.. opcode:: BUILD_MAP (count)
Pushes a new dictionary object onto the stack. The dictionary is pre-sized to hold *count* entries. Pushes a new dictionary object onto the stack. Pops ``2 * count`` items so that the dictionary holds *count* entries: ``{..., TOS3: TOS2, TOS1: TOS}``.
.. versionchanged:: 3.5 The dictionary is created from stack items instead of creating an empty dictionary pre-sized to hold *count* items.
.. opcode:: BUILD_TUPLE_UNPACK (count)
Pops *count* iterables from the stack, joins them in a single tuple, and pushes the result. Implements iterable unpacking in tuple displays ``(*x, *y, *z)``.
.. versionadded:: 3.5
.. opcode:: BUILD_LIST_UNPACK (count)
This is similar to :opcode:`BUILD_TUPLE_UNPACK`, but pushes a list instead of tuple. Implements iterable unpacking in list displays ``[*x, *y, *z]``.
.. versionadded:: 3.5
.. opcode:: BUILD_SET_UNPACK (count)
This is similar to :opcode:`BUILD_TUPLE_UNPACK`, but pushes a set instead of tuple. Implements iterable unpacking in set displays ``{*x, *y, *z}``.
.. versionadded:: 3.5
.. opcode:: BUILD_MAP_UNPACK (count)
Pops *count* mappings from the stack, merges them into a single dictionary, and pushes the result. Implements dictionary unpacking in dictionary displays ``{**x, **y, **z}``.
.. versionadded:: 3.5
.. opcode:: BUILD_MAP_UNPACK_WITH_CALL (oparg)
This is similar to :opcode:`BUILD_MAP_UNPACK`, but is used for ``f(**x, **y, **z)`` call syntax. The lowest byte of *oparg* is the count of mappings, the relative position of the corresponding callable ``f`` is encoded in the second byte of *oparg*.
.. versionadded:: 3.5
.. opcode:: LOAD_ATTR (namei) Expand Down