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Document math's lack of bitnot

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Fixes #9148
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Fabian Boehm 2022-08-23 19:54:10 +02:00
parent 9e9c73e46a
commit 7e75118956
1 changed files with 14 additions and 0 deletions
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doc_src/cmds/math.rst
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@ -121,6 +121,20 @@ Functions
``bitand``, ``bitor`` and ``bitxor``
perform bitwise operations.
These will throw away any non-integer parts and interpret the rest as an int.
Note: ``bitnot`` and ``bitnand`` don't exist. This is because numbers in math don't really have a *width* in terms of bits,
and tehse operations necessarily care about leading zeroes.
If you need to negate a specific number you can do it with an xor with a mask, e.g.::
> math --base=hex bitxor 0x0F, 0xFF
0xF0
> math --base=hex bitxor 0x2, 0x3
# Here we mask with 0x3 == 0b111, so our number is 3 bits wide
# Only the 1 bit isn't set.
0x1
``ceil``
round number up to nearest integer
``cos``