mirrors/Nim
1
0
Fork 0
mirror of https://github.com/nim-lang/Nim.git synced 2026-05-01 11:34:43 +00:00
Code Issues Packages Projects Releases Wiki Activity

breaking change: 'and' and 'mod' do not produce a subrange type anymore; fixes #5854

Browse Source
This commit is contained in:
Andreas Rumpf
2017-10-30 00:27:30 +01:00
parent aa526da706
commit d7a896f19d
6 changed files with 16 additions and 131 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
doc/manual/types.txt
View File

@@ -137,25 +137,6 @@ determined). Assignments from the base type to one of its subrange types
A subrange type has the same size as its base type (``int`` in the example).
Nim requires `interval arithmetic`:idx: for subrange types over a set
of built-in operators that involve constants: ``x %% 3`` is of
type ``range[0..2]``. The following built-in operators for integers are
affected by this rule: ``-``, ``+``, ``*``, ``min``, ``max``, ``succ``,
``pred``, ``mod``, ``div``, ``%%``, ``and`` (bitwise ``and``).
Bitwise ``and`` only produces a ``range`` if one of its operands is a
constant *x* so that (x+1) is a power of two.
(Bitwise ``and`` is then a ``%%`` operation.)
This means that the following code is accepted:
.. code-block:: nim
case (x and 3) + 7
of 7: echo "A"
of 8: echo "B"
of 9: echo "C"
of 10: echo "D"
# note: no ``else`` required as (x and 3) + 7 has the type: range[7..10]
Pre-defined floating point types