Hi! My name is Eduardo Ochs, and this is
another very short video that I'm
recording for the workshop that
I'm going to give in about 12 hours...
the title of this video is "Invisible
text",
Note that we are in a buffer with an
intro... it's the the intro with
exercises for the workshop...
and this is the title of a section.
It turns out that there's some invisible
text here. Let me show how we can
see that, and why this is annoying.
Suppose that I want to use this string
here - the contents of this line -
to refine a hyperlink.
Let's pretend that this is a hyperlink...
let me duplicate it, and now use
`M-h M-y' to yank the the text of the
kill ring into this hyperlink...
and note that we got some garbage here.
Instead of of getting just this part
here, with the name of the section,
we got this part here with the new line
and a series of dashes...
and this happened because
there's some invisible text here.
The new line and the dashes are
invisible text - long story that
I do not want to explain now...
and the workaround for this is
quite simple - if we know the trick,
of course. If we want to copy just this
thing without invisible text to the
the ring we have to go to
the beginning of the line,
type `C-SPC' to set the mark, then
go to the end of the line,
then move left, and then move right...
and now the point is going to be before
the invisible text,
and if we type `M-w'
we can see that everything worked -
the garbage is not here.
This is going to be important for the
exercise of this section.
The exercise says:
"create a pair of elisp hyperlinks,
the first hyperlink pointing to this
intro - this one - and the second one
being a refinement of this, of the
first one, that points to the title of
this section here...
and then copy the pair to our notes".
Let me show how to do that. I'm going to
cheat a bit because I can copy this
thing to my notes...
oopsm it's already here, from my last
rehearsal... so, I've just copied this
into my notes, and now I have to follow
these instructions...
i'll have to switch to a smaller font...
we are in this buffer here,
"...exercises...", that i'm abbreviating
as "ex", and we have to type `M-w'
in the right place
to copy this title to the kill ring.
But I'm going to use the trick,
which is to move left and then move
right.
Now I'm going to type `M-h M-h', which is
`find-here-links'...
to create a buffer with a hyperlink to
here - to this intro...
and right after that I'm going to type
`M-21j', or `M-2 M-1 M-j',
to show my notes at the right window.
Let me do that...
Here are my notes. Now i can follow the
instructions here - much easier than
having to memorize things.
These instructions are a bit incomplete,
they do not say things that I can
pretend that are obvious, and they say
that here, in the buffer with elisp
hyperlinks, i have to type `M-h M-2',
which is "duplicate the current line"...
I'm going to do this, here...
so: I duplicate this line, and then I
have to type this to yank
the top of the kill ring...
to refine the sexp in the current line.
So: `M-h M-y' here... that's it, I got
the refined version - and then
there's something that I've
omitted here, which is a `M-w' to
copy these things to the kill ring...
but I forgot to omit the `C-y' here,
so let me copy this thing...
and then `C-y' to copy these links to
my notes... and that's it!
I got the link to the title
of that section in my notes...
and then the instructions say
"use `C-x 1' and then a series of
`M-K's to go back to the
buffer with exercises...
here we are back - to the exercises...
and let's now test the hyperlink
that we have just created.
I'm going to delete this buffer
with `M-k' - not `M-K', just `M-k'...
well, lots of things here...
anyway, let me go back to my notes.
Here we have the unrefined link. If we
follow it we we go to this intro here,
but to the beginning of it...
and if we execute this link here we go
to that intro, but to the title
of this section.
And that's it! =)