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Re: [Help-bash] Can `declare -i` increase the performance of integer ari
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From: |
Chet Ramey |
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Subject: |
Re: [Help-bash] Can `declare -i` increase the performance of integer arithmetic? |
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Date: |
Mon, 22 Jan 2018 09:28:52 -0500 |
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User-agent: |
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 |
On 1/22/18 8:48 AM, Peng Yu wrote:
>> No, it's not meant to improve performance.
>
> Then, what is the purpose of `declare -i`?
The purpose is as documented.
For assignment statements:
"If the variable has its integer attribute set, then value
is evaluated as an arithmetic expression even if the $((...)) expansion
is not used (see Arithmetic Expansion below)."
This has implications for how += is treated when applied to a variable
with the integer attribute set.
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU address@hidden http://tiswww.cwru.edu/~chet/