WEBVTT
Kind: captions:
Language: en-GB
00:00:00.000 --> 00:00:04.000
Hi! My name is Eduardo Ochs. I'm the author
00:00:04.000 --> 00:00:06.000
of an Emacs package called eev, and the name
00:00:06.000 --> 00:00:09.000
of this presentation is: "Bidirectional links
00:00:09.000 --> 00:00:10.000
in eev".
00:00:10.000 --> 00:00:13.000
Let me present things in a weird order,
00:00:13.000 --> 00:00:16.000
starting by the new feature, and then I'm
00:00:16.000 --> 00:00:20.000
going to explain the whole context.
00:00:20.000 --> 00:00:22.000
One of the main features that we are
00:00:22.000 --> 00:00:24.000
going to see here is this function here,
00:00:24.000 --> 00:00:27.000
M-x kla, and kla is a mnemonic for "kill
00:00:27.000 --> 00:00:31.000
Link to Anchor". Let me explain... let me
00:00:31.000 --> 00:00:33.000
demonstrate how it works. This thing here
00:00:33.000 --> 00:00:36.000
with the green angle brackets is an
00:00:36.000 --> 00:00:40.000
anchor, this thing between the green
00:00:40.000 --> 00:00:42.000
angle brackets is a tag of an
00:00:42.000 --> 00:00:46.000
anchor, and if I type M-x kla here
00:00:46.000 --> 00:00:49.000
it highlights this tag for a second and
00:00:49.000 --> 00:00:52.000
it says "Copied to the kill ring: blah
00:00:52.000 --> 00:00:54.000
blah blah..." and this thing here is a link.
00:00:54.000 --> 00:00:57.000
I can insert the link here, I
00:00:57.000 --> 00:01:00.000
can insert the link in my notes...
00:01:00.000 --> 00:01:03.000
and if I execute this thing this link
00:01:03.000 --> 00:01:10.000
here it goes to this anchor in this file.
00:01:10.000 --> 00:01:12.000
If you have a recent version of eev
00:01:12.000 --> 00:01:13.000
installed then trying this feature
00:01:13.000 --> 00:01:15.000
should be very easy...
00:01:15.000 --> 00:01:18.000
you just need to open the this file here,
00:01:18.000 --> 00:01:21.000
in which everything is defined, and then
00:01:21.000 --> 00:01:23.000
go to this section at the beginning of
00:01:23.000 --> 00:01:26.000
the file, and then run the three blocks
00:01:26.000 --> 00:01:28.000
of tests that are there.
00:01:28.000 --> 00:01:31.000
This block corresponds roughly to what
00:01:31.000 --> 00:01:33.000
we have just done...
00:01:33.000 --> 00:01:36.000
this other block
00:01:36.000 --> 00:01:40.000
is slightly different because it shows
00:01:40.000 --> 00:01:44.000
some variants of kla... one is with `f'
00:01:44.000 --> 00:01:48.000
instead of an `a' here, let me
00:01:48.000 --> 00:01:51.000
show how it works... if we type
00:01:51.000 --> 00:01:57.000
`M-x eeklf' or just `M-x klf'
00:01:57.000 --> 00:02:00.000
we get a link to this file that does not
00:02:00.000 --> 00:02:03.000
point to an anchor, and if we type
00:02:03.000 --> 00:02:07.000
`M-x klt' we get another kind of link that
00:02:07.000 --> 00:02:09.000
is a link to an anchor in the same
00:02:09.000 --> 00:02:11.000
file...
00:02:11.000 --> 00:02:16.000
and the third block
00:02:16.000 --> 00:02:18.000
is more interesting because it lets
00:02:18.000 --> 00:02:20.000
people create links to files that
00:02:20.000 --> 00:02:23.000
are elsewhere, and that do not have
00:02:23.000 --> 00:02:25.000
anchors in them...
00:02:25.000 --> 00:02:29.000
let me execute this... this will
00:02:29.000 --> 00:02:32.000
run this sexp here and display the
00:02:32.000 --> 00:02:35.000
target at the window at the right...
00:02:35.000 --> 00:02:41.000
this is one of the source files of Emacs.
00:02:41.000 --> 00:02:43.000
Let's imagine that I want to create a
00:02:43.000 --> 00:02:46.000
link to this string here... then I can
00:02:46.000 --> 00:02:51.000
type `M-x klfs', and this will create a
00:02:51.000 --> 00:02:53.000
link to a file and to a string in that
00:02:53.000 --> 00:02:56.000
file. So if I type ENTER here
00:02:56.000 --> 00:02:59.000
it says: "Copied to the kill ring: ...\
00:02:59.000 --> 00:03:02.000
and this is a link to this file here,
00:03:02.000 --> 00:03:04.000
and to the first occurrence of this
00:03:04.000 --> 00:03:10.000
string in this file.
00:03:10.000 --> 00:03:14.000
So: how does this work (inside)?...
00:03:14.000 --> 00:03:16.000
when I was trying to write the documentation
00:03:16.000 --> 00:03:19.000
of this I tried to write a summary of
00:03:19.000 --> 00:03:21.000
how the algorithm works, and I failed and
00:03:21.000 --> 00:03:23.000
I tried again, and I failed again,
00:03:23.000 --> 00:03:26.000
several times... and then I gave up and I
00:03:26.000 --> 00:03:29.000
decided to write an intro - a tutorial,
00:03:29.000 --> 00:03:31.000
this one -
00:03:31.000 --> 00:03:34.000
that explains everything with lots of
00:03:34.000 --> 00:03:35.000
details, and with lots of sections
00:03:35.000 --> 00:03:39.000
with "Try it!"s, that
00:03:39.000 --> 00:03:41.000
have examples that you you can run to
00:03:41.000 --> 00:03:44.000
understand things, to examine how some
00:03:44.000 --> 00:03:48.000
functions work, how the data
00:03:48.000 --> 00:03:51.000
structures work, and so on...
00:03:51.000 --> 00:03:54.000
the problem is that sometimes we have
00:03:54.000 --> 00:03:56.000
several hyperlinks that point to the to
00:03:56.000 --> 00:04:00.000
the same file. Let me give an example.
00:04:00.000 --> 00:04:04.000
In the configuration in which I am now,
00:04:04.000 --> 00:04:07.000
in this file here... the old way of
00:04:07.000 --> 00:04:08.000
generating hyperlinks to this file
00:04:08.000 --> 00:04:10.000
with `find-here-links'
00:04:10.000 --> 00:04:13.000
will generate a temporary buffer
00:04:13.000 --> 00:04:15.000
like this, and then I would have to
00:04:15.000 --> 00:04:18.000
choose which one of these hyperlinks I
00:04:18.000 --> 00:04:21.000
find best, which one I prefer, and then
00:04:21.000 --> 00:04:25.000
copy it to my notes... so instead
00:04:25.000 --> 00:04:27.000
of choosing a hyperlink this thing here
00:04:27.000 --> 00:04:30.000
shows all the options.
00:04:30.000 --> 00:04:34.000
And in the new way, in `M-x kla'
00:04:34.000 --> 00:04:37.000
and friends, there's an algorithm that
00:04:37.000 --> 00:04:39.000
chooses the best short hyperlink by
00:04:39.000 --> 00:04:43.000
itself, and this algorithm is a bit hard
00:04:43.000 --> 00:04:46.000
to explain... let me demonstrate it here.
00:04:46.000 --> 00:04:50.000
Again, we have all these options here, of
00:04:50.000 --> 00:04:51.000
hyperlinks to this file...
00:04:51.000 --> 00:04:56.000
and if I type `M-x klf'
00:04:56.000 --> 00:04:58.000
it chooses one of them.
00:04:58.000 --> 00:05:01.000
And of course I can copy it to my notes,
00:05:01.000 --> 00:05:02.000
it's going to work, it's going to point
00:05:02.000 --> 00:05:05.000
to here... and so on.
00:05:05.000 --> 00:05:08.000
Well, the title of this presentation was
00:05:08.000 --> 00:05:11.000
"Bidirectional links with eev"... let me
00:05:11.000 --> 00:05:13.000
show what I mean by bi-directional
00:05:13.000 --> 00:05:15.000
hyperlinks, and how we can use this thing
00:05:15.000 --> 00:05:17.000
to create bidirectional hyperlinks
00:05:17.000 --> 00:05:19.000
very quickly.
00:05:19.000 --> 00:05:22.000
I will have to use a smaller font... let
00:05:22.000 --> 00:05:25.000
me open these two files here. This one at
00:05:25.000 --> 00:05:27.000
the left is a program in Haskell, and
00:05:27.000 --> 00:05:30.000
this one is a file with my notes on
00:05:30.000 --> 00:05:31.000
Haskell.
00:05:31.000 --> 00:05:35.000
How do I create a link from...
00:05:35.000 --> 00:05:39.000
to this file in Haskell
00:05:39.000 --> 00:05:42.000
to put it in this file here? I can put
00:05:42.000 --> 00:05:45.000
the cursor here, in any position
00:05:45.000 --> 00:05:48.000
after this anchor here, and type
00:05:48.000 --> 00:05:49.000
`M-x kla'...
00:05:49.000 --> 00:05:51.000
it copies this link here to the kill
00:05:51.000 --> 00:05:54.000
ring and then I can can go here and
00:05:54.000 --> 00:05:59.000
either insert it with C-y (yank), or
00:05:59.000 --> 00:06:06.000
insert it with `M-k kli', that adds a
00:06:06.000 --> 00:06:07.000
comment prefix here.
00:06:07.000 --> 00:06:11.000
So this is a way to create a link from
00:06:11.000 --> 00:06:15.000
here to there in which every
00:06:15.000 --> 00:06:18.000
comment has to be given explicitly...
00:06:18.000 --> 00:06:21.000
but I also implemented a way to
00:06:21.000 --> 00:06:23.000
create the two links at the same time.
00:06:23.000 --> 00:06:25.000
I don't use it much, it's mostly for
00:06:25.000 --> 00:06:27.000
demos, because it's impressive, I wanted
00:06:27.000 --> 00:06:29.000
to show that in this presentation...
00:06:29.000 --> 00:06:33.000
Anyway, let me show it here. Note that
00:06:33.000 --> 00:06:36.000
that in this file here the point is
00:06:36.000 --> 00:06:40.000
here, in this file the point is here...
00:06:40.000 --> 00:06:43.000
My trick is going to create a link to
00:06:43.000 --> 00:06:47.000
this anchor and put it in this file, and
00:06:47.000 --> 00:06:49.000
it's going to create a link to this
00:06:49.000 --> 00:06:52.000
anchor and put it in this file...
00:06:52.000 --> 00:06:57.000
So, here it goes: `M-x kla2'... ta-da!
00:06:57.000 --> 00:07:01.000
it highlighted the true anchors for a
00:07:01.000 --> 00:07:03.000
second, and it created these things here
00:07:03.000 --> 00:07:06.000
and inserted them with the
00:07:06.000 --> 00:07:09.000
right prefixes, I mean, the right
00:07:09.000 --> 00:07:10.000
comment prefixes.
00:07:10.000 --> 00:07:15.000
And that's it!
00:07:15.000 --> 00:07:18.000
So... that's it. If you found this thing
00:07:18.000 --> 00:07:22.000
interesting just
00:07:22.000 --> 00:07:25.000
install a recent version of eev and run
00:07:25.000 --> 00:07:28.000
the tutorial, either with this thing here,
00:07:28.000 --> 00:07:30.000
`M-x find-kla-intro', or by running
00:07:30.000 --> 00:07:35.000
this sexp, or open this file here in the
00:07:35.000 --> 00:07:37.000
eev directory, and follow the
00:07:37.000 --> 00:07:39.000
tutorials...
00:07:39.000 --> 00:07:42.000
most things that there are well
00:07:42.000 --> 00:07:46.000
documented, but the thing that I don't
00:07:46.000 --> 00:07:47.000
use much and that is mostly for demos,
00:07:47.000 --> 00:07:50.000
which is the the thing that creates
00:07:50.000 --> 00:07:52.000
bi-directional hyperlinks, is not yet
00:07:52.000 --> 00:07:55.000
well documented, but the rest is.
00:07:55.000 --> 00:07:57.000
So: that's it! Bye! Have fun! =)
