29 lines
1.0 KiB
ReStructuredText
29 lines
1.0 KiB
ReStructuredText
:mod:`micropython` -- MicroPython extensions and internals
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==========================================================
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.. module:: micropython
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:synopsis: access and control MicroPython internals
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Functions
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---------
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.. function:: const(expr)
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Used to declare that the expression is a constant so that the compiler can
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optimise it. The use of this function should be as follows::
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from micropython import const
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CONST_X = const(123)
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CONST_Y = const(2 * CONST_X + 1)
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Constants declared this way are still accessible as global variables from
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outside the module they are declared in. On the other hand, if a constant
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begins with an underscore then it is hidden, it is not available as a global
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variable, and does not take up any memory during execution.
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This `const` function is recognised directly by the MicroPython parser and is
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provided as part of the :mod:`micropython` module mainly so that scripts can be
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written which run under both CPython and MicroPython, by following the above
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pattern.
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