Unnecessary variable shr-start

Unnecessary variable shr-start

[Hong Xu]

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In the current master branch, it seems that the variable shr-start has
never been used in any sensible way: Every time its value is referred,
it is bound to nil. Should it be considered to be removed?

Hong

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Re: Unnecessary variable shr-start

[Michael Heerdegen]

Hong Xu <hong@topbug.net> writes:

> In the current master branch, it seems that the variable shr-start has
> never been used in any sensible way: Every time its value is referred,
> it is bound to nil. Should it be considered to be removed?

Are you sure it is always bound to nil when referenced in `shr-tag-a'?
I would expect it can be changed by side effect in the body, and the
let-binding is there to make that change temporary.


Michael.

Re: Unnecessary variable shr-start

[Matthew Carter]

Michael Heerdegen <michael_heerdegen@web.de> writes:

> Hong Xu <hong@topbug.net> writes:
>
>> In the current master branch, it seems that the variable shr-start has
>> never been used in any sensible way: Every time its value is referred,
>> it is bound to nil. Should it be considered to be removed?
>
> Are you sure it is always bound to nil when referenced in `shr-tag-a'?
> I would expect it can be changed by side effect in the body, and the
> let-binding is there to make that change temporary.
>
>
> Michael.
>

It looks like it's bound at the top defvar level (and changed via setq
in the img function), so those let's to nil in certain functions are
likely to inhibit the current setting when those functions begin to
run.

-- 
Matthew Carter (m@ahungry.com)
http://ahungry.com

Re: Unnecessary variable shr-start

[Hong Xu]

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On 2016-12-02 Fri 22:54 GMT-0800, Matthew Carter <m@ahungry.com> wrote:

> Michael Heerdegen <michael_heerdegen@web.de> writes:
>
>> Hong Xu <hong@topbug.net> writes:
>>
>>> In the current master branch, it seems that the variable shr-start has
>>> never been used in any sensible way: Every time its value is referred,
>>> it is bound to nil. Should it be considered to be removed?
>>
>> Are you sure it is always bound to nil when referenced in `shr-tag-a'?
>> I would expect it can be changed by side effect in the body, and the
>> let-binding is there to make that change temporary.
>>
>>
>> Michael.
>>
>
> It looks like it's bound at the top defvar level (and changed via setq
> in the img function), so those let's to nil in certain functions are
> likely to inhibit the current setting when those functions begin to
> run.

That's exactly what I meant: Every time it is referred, it is bound to
nil by a let.

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Re: Unnecessary variable shr-start

[Katsumi Yamaoka]

On Sun, 04 Dec 2016 12:01:57 -0800, Hong Xu wrote:
> That's exactly what I meant: Every time it is referred, it is bound to
> nil by a let.

`shr-tag-a' binds `shr-start' to nil, runs `shr-generic' that
sets non-nil value to `shr-start' in the following way, and
refers to `shr-start'.

`shr-generic' runs `shr-descend'
`shr-descend' runs `shr-tag-img'
`shr-tag-img' sets non-nil value to `shr-start'

;-)

Re: Unnecessary variable shr-start

[Hong Xu]

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On 2016-12-05 Mon 00:25 GMT-0800, Katsumi Yamaoka <yamaoka@jpl.org> wrote:

> On Sun, 04 Dec 2016 12:01:57 -0800, Hong Xu wrote:
>> That's exactly what I meant: Every time it is referred, it is bound to
>> nil by a let.
>
> `shr-tag-a' binds `shr-start' to nil, runs `shr-generic' that
> sets non-nil value to `shr-start' in the following way, and
> refers to `shr-start'.
>
> `shr-generic' runs `shr-descend'
> `shr-descend' runs `shr-tag-img'
> `shr-tag-img' sets non-nil value to `shr-start'
>
> ;-)

Such a complicated story! Thank you for pointing it out!

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Re: Unnecessary variable shr-start

[Tino Calancha]

On Mon, 5 Dec 2016, Hong Xu wrote:

>
> On 2016-12-05 Mon 00:25 GMT-0800, Katsumi Yamaoka <yamaoka@jpl.org> wrote:
>
>> On Sun, 04 Dec 2016 12:01:57 -0800, Hong Xu wrote:
>>> That's exactly what I meant: Every time it is referred, it is bound to
>>> nil by a let.
>>
>> `shr-tag-a' binds `shr-start' to nil, runs `shr-generic' that
>> sets non-nil value to `shr-start' in the following way, and
>> refers to `shr-start'.
>>
>> `shr-generic' runs `shr-descend'
>> `shr-descend' runs `shr-tag-img'
>> `shr-tag-img' sets non-nil value to `shr-start'
>>
>> ;-)
>
> Such a complicated story! Thank you for pointing it out!
Yeah! It sounds amazing.  We should call it `shr-super-start'.