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bug#30816: 27.0.50; Info documentation of previous-property-change is no
From: |
Xu Chunyang |
Subject: |
bug#30816: 27.0.50; Info documentation of previous-property-change is not very clear |
Date: |
Thu, 15 Mar 2018 03:04:30 +0800 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/27.0.50 (darwin) |
Eli Zaretskii <eliz@gnu.org> writes:
>> From: Xu Chunyang <mail@xuchunyang.me>
>> Date: Wed, 14 Mar 2018 17:58:32 +0800
>>
>>
>> (info "(elisp) Property Search") has the following:
>>
>> -- Function: previous-property-change pos &optional object limit
>> This is like ‘next-property-change’, but scans back from POS
>> instead of forward. If the value is non-‘nil’, it is a position
>> ^^^^^^^^^
>> less than or equal to POS; it equals POS only if LIMIT equals POS.
>> ^^
>>
>> I don't understand the second sentence. What "the value" stands for?
>
> When we say "value" in the context of describing a function, we mean
> the value the function returns. In this case, the value returned by
> previous-property-change.
I see. I notice the term "the return value" is also used in some place
in the manual.
>> If it stands for LIMIT, what "it" stands for?
>
> "It" stands for the value returned by the function. the text says
> that the function returns the position of the previous change of the
> property, and that position could only be the same as the starting
> position POS if LIMIT is equal to POS, i.e. if LIMIT forces the
> function to stop at its starting position.
>
> I hope this clarifies the issue.
Thanks for your explanation. Feel free to close the issue.