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Re: No word splitting for assignment-like expressions in compound assignment

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On 2020-07-27 10:06, Lawrence Velázquez wrote:
>> On Jul 27, 2020, at 1:31 AM, Dale R. Worley <worley@alum.mit.edu> 
>> wrote:
>> Interesting.  The documentation for 4.2.53(1) says this about 
>> parameter
>> assignments generally, with no special rules for compound assignments:
>> 
>>       All
>>       values undergo tilde expansion, parameter and variable 
>> expansion,  com-
>>       mand  substitution, arithmetic expansion, and quote removal (see 
>> EXPAN-
>>       SION below).  ...  Word  splitting  is  not
>>       performed,  with the exception of "$@" as explained below under 
>> Special
>>       Parameters.  Pathname expansion is not  performed.
>> 
>> So it seems like the word splitting in "A=(X$Z)" is incorrect.  So is
>> pathname expansion in that context.
> 
> 
> If word splitting were not performed in compound assignments, this...
> 
>     foo=(a b c)
> 
> ...would not work. If pathname expansion were not performed in compound
> assignments, this...
> 
>     foo=(*)
> 
> ...would not work. Arrays would become significantly less usable if
> word splitting and pathname expansion were not allowed in compound
> assignments.
> 
To be clear, I don't consider word splitting and expansions in compound 
assignments to be a problem: this is well-known and long-standing 
behavior, even though it doesn't seem to be explicitly documented. In 
particular, I expect word splitting to happen in "A=(X$Z)" case. But I 
expect it to happen in "A=(X=$Z)" too, and the lack of it seems 
unintentional to me.

Alexey

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Re: No word splitting for assignment-like expressions in compound assignment Alexey Izbyshev <izbyshev@ispras.ru> - 2020-07-27 10:25 +0300

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