This is the last remnant of the old percent expansion.
It has the downsides of it, in that it is annoying to combine with
anything:
```fish
echo %self/foo
```
prints "%self/foo", not fish's pid.
We have introduced $fish_pid in 3.0, which is much easier to use -
just like a variable, because it is one.
If you need backwards-compatibility for < 3.0, you can use the
following shim:
```fish
set -q fish_pid
or set -g fish_pid %self
```
So we introduce a feature-flag called "remove-percent-self" to turn it
off.
"%self" will simply not be special, e.g. `echo %self` will print
"%self".
This committed the sin of introducing a concept by giving it two
names:
> An alias, or wrapper, around ``ls`` might look like this
The term "wrapper" doesn't pull its weight here. It's simpler to just
call them aliases throughout. We do use "a simple wrapping function"
in another place, but that's to define "alias", not as a separate name.
It reads nicer to not have the "see also" thing right in the first
paragraph. I'm not even done reading this, why are you sending me
elsewhere?
(of course if it's a hotlink on a specific word that's different)
I'm not sure if line continuations are covered anywhere else in the docs, but I
think the escapes section of the language page is a good place to mention them.
- Clean up the wording a little.
- Highlight the limitations of the "debugger" more clearly and don't mislead
people into thinking it's possible to really interactively set/remove
breakpoints except in select circumstances.
Sidenote: I can't believe we're using a markup language that doesn't support
nested inline markup. What a crying shame, rST!
Up to now, in normal locales \x was essentially the same as \X, except
that it errored if given a value > 0x7f.
That's kind of annoying and useless.
A subtle change is that `\xHH` now represents the character (if any)
encoded by the byte value "HH", so even for values <= 0x7f if that's
not the same as the ASCII value we would diverge.
I do not believe anyone has ever run fish on a system where that
distinction matters. It isn't a thing for UTF-8, it isn't a thing for
ASCII, it isn't a thing for UTF-16, it isn't a thing for any extended
ASCII scheme - ISO8859-X, it isn't a thing for SHIFT-JIS.
I am reasonably certain we are making that same assumption in other
places.
Fixes#1352
