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
There are many applications with "primitive" argument parsing capabalities that
cannot handle munging two short options together (`-xf` for `-x -f`) or a short
option and its required value (`-dall` for `-d all`). To prevent fish from
suggesting munged arguments/payloads, the options (both long and short, not just
long!) can be specified as `-o` or `--old-option` but none of this is
documented.
Hyphenation in our documentation is aggressive, even to the point of caus-
ing options themselves to be broken across lines. This makes the document-
ation hard to read, especially when you have an option like `string colle-
ct` which gets a weird hyphen.
Remove the hyphenation from the CSS.
This makes it so we link to the very top of the document instead of a
special anchor we manually include.
So clicking e.g. :doc:`string <cmds/string>` will link you to
cmds/string.html instead of cmds/string.html#cmd-string.
I would love to have a way to say "this document from the root of the
document path", but that doesn't appear to work, I tried
`/cmds/string`.
So we'll just have to use cmds/string in normal documents and plain
`string` from other commands.
This is essentially the inverse of `string pad`.
Where that adds characters to get up to the specified width,
this adds an ellipsis to a string if it goes over a specific maximum width.
The char can be given, but defaults to our ellipsis string.
("…" if the locale can handle it and "..." otherwise)
If the ellipsis string is empty, it just truncates.
For arguments given via argv, it goes line-by-line,
because otherwise length makes no sense.
If "--no-newline" is given, it adds an ellipsis instead and removes all subsequent lines.
Like pad and `length --visible`, it goes by visible width,
skipping recognized escape sequences, as those have no influence on width.
The default target width is the shortest of the given widths that is non-zero.
If the ellipsis is already wider than the target width,
we truncate instead. This is safer overall, so we don't e.g. move into a new line.
This is especially important given our default ellipsis might be width 3.
This was written while we changed how our synopses are formatted, so
we missed adding a "synopsis" marker to it.
The tokenizer here is a bit cheesy, so we can't mark continuation
lines with a "\", and we also can't mark the general options with a
":=". Tbh that's not a big deal.
Fixes#9154
Note that every change to the search field still starts a new search, from
the end of history. We could change this in future but it's unclear to me
what the expected behavior is. I don't find the traditional readline behavior
very intuitive.
This reimplements ridiculousfish/control_r which is a more future-proof
approach than #6686.
Pressing Control+R shows history in our pager and allows to search filter
commands with the pager search field.
On the surface, this works just like in other shells; though there are
some differences.
- Our pager shows multiple results at a time.
- Other shells allow to use up arrow/down arrow to select adjacent entries
in history. Shouldn't be hard to implement but the hidden state might
confuse users and it doesn't play well with up-or-search, so this is
left out.
Users might expect the history pager to use subsequence matching (fuzzy
matching) like the completion pager, however due to the history pager design it
uses substring matching. We could change this in future, however that means
we would also want to change the ordering from "reverse-chronological" to
"longest common subsequence" (e.g. what fuzzy finders do), because otherwise
a query "fis" might give this ordering:
fsck /dev/disk/by-partlabel/Linux\x20filesystem
fish
which is probably not what the user wants.
The pager shows only a small number of history items at a time. This is
because, as explained above, the history pager does not support subsequence
matching, so navigating it does not scale well.
Closes#602
PR #6777 changed all the keys to uppercase, but many Vi commands are case
sensitive.
PR #7908 changed the "u" binding but the documentation still had the old
meaning.
This can be used to print the modification time, like `stat` with some
options.
The reason is that `stat` has caused us a number of portability
headaches:
1. It's not available everywhere by default
2. The versions are quite different
For instance, with GNU stat it's `stat -c '%Y'`, with macOS it's `stat
-f %m`.
So now checking a cache file can be done just with builtins.
It's still useful without, for instance to implement a command that
takes no options, or to check min-args or max-args.
(technically no optspecs, no min/max args and --ignore-unknown does
nothing, but that's a very specific error that we don't need to forbid)
Fixes#9006
This enhances our documentation to look for the file
/release_version.json in the root of our site. If found, and if it
contains a RELEASE_VERSION other than this version, then unhide a banner
warning about the stale documentation and linking to the current.
Unlike before, this doesn't force the number to be on the same line as
strongly, that's fine.
So short footnotes look like
-------------
[1] Some text
-------------
Longer footnotes may look like
--------------
[2]
Some more text
--------------
The "Warning:" on the warning (in index.html#default shell) wasn't in
the line with the text, the features list had more padding and some
headers were smaller, some table stuff
This has required workarounds a few times, plus if it changes it might
break our theme. See e.g.
4712da3eb1e27456df24a6d484836e85522036f5
So we import the rules we *use* and throw away the rest. Note that
this might still have rules that are no longer necessary - e.g. some
that are required to work around sphinx bugs would still be left.
It could benefit from some cleanup and simplification, and from
switching to a flex layout instead of the 230px hardcoded
sidebar - sphinx tried that, but it doesn't really work with our
narrow layout, so we disabled it again.
This makes it so
1. The informative status can work without showing untracked
files (previously it was disabled if bash.showUntrackedFiles was
false)
2. If untrackedfiles isn't explicitly enabled, we use -uno, so git
doesn't have to scan all the files.
In a large repository (like the FreeBSD ports repo), this can improve
performance by a factor of 5 or up.
Previously, `kill-whole-line` kills the line and its following
newline. This is insufficient when we are on the last line, because
it would not actually clear the line. The cursor would stay on the
line, which is not the correct behavior for bindings like `dd`.
Also, `cc` in vi-mode used `kill-whole-line`, which is not correct
because it should not remove any newlines. We have to introduce
another special input function (`kill-inner-line`) to fix this.
This is broken in narrow screens - the sidebar shrinks to unusable
proportions but still stays.
So instead we go the *other* way, force the left margin and undo the flexifying.
(again we should really stop relying on sphinx' css)
Sphinx 5.0 makes the document div a flex container, which clashes
badly with the margin that earlier versions need.
So we remove the margin and flex the div ourselves, which should work
with either.
It's time we make this freestanding - these changes are annoying.
This makes it so `complete -c foo -n test1 -n test2` registers *both*
conditions, and when it comes time to check the candidate, tries both,
in that order. If any fails it stops, if all succeed the completion is offered.
The reason for this is that it helps with caching - we have a
condition cache, but conditions like
```fish
test (count (commandline -opc)) -ge 2; and contains -- (commandline -opc)[2] length
test (count (commandline -opc)) -ge 2; and contains -- (commandline -opc)[2] sub
```
defeats it pretty easily, because the cache only looks at the entire
script as a string - it can't tell that the first `test` is the same
in both.
So this means we separate it into
```fish
complete -f -c string -n "test (count (commandline -opc)) -ge 2; and contains -- (commandline -opc)[2] length" -s V -l visible -d "Use the visible width, excluding escape sequences"
+complete -f -c string -n "test (count (commandline -opc)) -ge 2" -n "contains -- (commandline -opc)[2] length" -s V -l visible -d "Use the visible width, excluding escape sequences"
```
which allows the `test` to be cached.
In tests, this improves performance for the string completions by 30%
by reducing all the redundant `test` calls.
The `git` completions can also greatly benefit from this.
This adds a path builtin to deal with paths.
It offers the following subcommands:
filter to go through a list of paths and only print the ones that pass some filter - exist, are a directory, have read permission, ...
is as a shortcut for filter -q to only return true if one of the paths passed the filter
basename, dirname and extension to print certain parts of the path
change-extension to change the extension to a different one (as a string operation)
normalize and resolve to canonicalize the paths in various flavors
sort to sort paths, also only using the basename or dirname as a key
The definition of "extension" here was carefully considered and should line up with how extensions are actually used - ~/.bashrc doesn't have an extension, but ~/.conf.d does (".d").
These subcommands all compose well - they can read from arguments or stdin (like string), they can use null-delimited input or output (input is autodetected - if a NULL happens in the first PATH_MAX bytes it switches automatically).
It is both a failglob exception (so like set if a glob passed to it fails it just doesn't get any arguments for it instead of triggering an error), and passes output to command substitution buffers explicitly split (like string split0) so newlines are easy to handle.
This is now added to the two commands that definitely deal with
relative paths.
It doesn't work for e.g. `path basename`, because after removing the
dirname prepending a "./" doesn't refer to the same file, and the
basename is also expected to not contain any slashes.
This includes the "." in what `path extension` prints.
This allows distinguishing between an empty extension (just `.`) and a
non-existent extension (no `.` at all).
These are short flags for "--perm=read" and "--type=link" and such.
Not every type or permission has a shorthand - we don't want "-s" for
"suid". So just the big three each get one.
This is theoretically sound, because a path can only be PATH_MAX - 1
bytes long, so at least the PATH_MAXest byte needs to be a NULL.
The one case this could break is when something has a NULL-output mode
but doesn't bother printing the NULL for only one path, and that path
contains a newline. So we leave --null-in there, to force it on.
This adds a "path" builtin that can handle paths.
Implemented so far:
- "path filter PATHS", filters paths according to existence and optionally type and permissions
- "path base" and "path dir", run basename and dirname, respectively
- "path extension PATHS", prints the extension, if any
- "path strip-extension", prints the path without the extension
- "path normalize PATHS", normalizes paths - removing "/./" components
- and such.
- "path real", does realpath - i.e. normalizing *and* link resolution.
Some of these - base, dir, {strip-,}extension and normalize operate on the paths only as strings, so they handle nonexistent paths. filter and real ignore any nonexistent paths.
All output is split explicitly, so paths with newlines in them are
handled correctly. Alternatively, all subcommands have a "--null-input"/"-z" and "--null-output"/"-Z" option to handle null-terminated input and create null-terminated output. So
find . -print0 | path base -z
prints the basename of all files in the current directory,
recursively.
With "-Z" it also prints it null-separated.
(if stdout is going to a command substitution, we probably want to
skip this)
All subcommands also have a "-q"/"--quiet" flag that tells them to skip output. They return true "when something happened". For match/filter that's when a file passed, for "base"/"dir"/"extension"/"strip-extension" that's when something about the path *changed*.
Filtering
---------
`filter` supports all the file*types* `test` has - "dir", "file", "link", "block"..., as well as the permissions - "read", "write", "exec" and things like "suid".
It is missing the tty check and the check for the file being non-empty. The former is best done via `isatty`, the latter I don't think I've ever seen used.
There currently is no way to only get "real" files, i.e. ignore links pointing to files.
Examples
--------
> path real /bin///sh
/usr/bin/bash
> path extension foo.mp4
mp4
> path extension ~/.config
(nothing, because ".config" isn't an extension.)
This teaches `--on-signal SIGINT` (and by extension `trap cmd SIGINT`)
to work properly in scripts, not just interactively. Note any such
function will suppress the default behavior of exiting. Do this for
SIGTERM as well.
With sphinx 4.5.0:
1. Some of our builtins actually give results (cd, end, set)
2. Some give broken results (and, if, or)
3. Only "for" even triggers the help page we hacked in
So this is of dubious use, and removing it gets us out of the awkward situation of shipping it.
Plus upstream sphinx has ditched jquery, so we would have to rewrite it anyway.
This can no longer be changed. If "no-stderr-nocaret" is in
$fish_features it will simply be ignored.
The "^" redirection that was deprecated in fish 3.0 is now gone for good.
Note: For testing reasons, it can still be set _internally_ by running
"feature_flags_t::set". We simply shouldn't do that.
Currently, when a variable like $fish_color_command is set but empty:
set -g fish_color_command
what happens is that highlight parses it and ends up with a "normal"
color.
Change it so instead it sees that the variable is empty and goes
on to check the fallback variable, e.g. fish_color_normal.
That makes it easier to make themes that override variables.
This means that older themes that expect an empty variable to be
"normal" need to be updated to set it to "normal".
Following from this, we could make writing .theme files easier by no
longer requiring them to list all variables with specific values.
Either the theme reader could be updated to implicitly set known color
variables to empty, or the themes could feature empty values.
See #8787.
* New -n flag for string join command.
This is an argument that excludes empty result items. Fixes#8351
* New documentation for string-join.
The new argument --no-empty was added at string-join manpage.
* New completions for the new -n flag for string join.
* Remove the documentation of the new -n flag of string join0
The reason to remove this new argument in the join0 is that this flag basically doesn't make any difference in the join0.
* Refactor the validation for the string join.
The string join command was using the length of the argument, this commit changes the validation to use the empty function.
* Revert #4b56ab452
The reason for the revert is thath the build broke on the ubuntu in the Github actions.
* Revert #e72e239a1
The reason the compilation on GitHub broke is that the test was weird, it didn't even run it, Common CI systems are typically very very resource-constrained.
* Resolve conflicts in the string-join.rst.
* Resolve conflicts in the "string-join.rst".
commit #1242d0fd7 not fixed all conflicts.
* Implement fish_wcstod_underscores
* Add fish_wcstod_underscores unit tests
* Switch to using fish_wcstod_underscores in tinyexpr
* Add tests for math builtin underscore separator functionality
* Add documentation for underscore separators for math builtin
* Add a changelog entry for underscore numeric separators
Otherwise this does "justify", which in bad cases can spread the text
over the width of the whole line, leaving awkward space between words.
This looks something like
```
The main file is ~/.config/fish/config.fish
```
The current python docs theme also left-aligns.
If a code block includes a line starting with ">", we assume it shows
an interactive session, all lines starting with ">" are commands and
the rest is output.
Unfortunately, in something like:
```
> for val in $PATh
echo "entry: $val"
end
entry: /usr/bin
```
this won't highlight the dangling lines. We could also prefix them
with `>`, but that require us to parse them in blocks or the `end`
would be an error.
So, for now, simply don't give these as a prompt but as a script with
cheesy comments describing the output.
Includes harmonizing the display of options and arguments, standardising
terminology, using the envvar directive more broadly, adding help options to all
commands that support them, simplifying some language, and tidying up multiple
formatting issues.
string documentation is not changed.
man(1) uses lowercase placeholders but we usually don't. Additionally,
the new synopsis autoformatting only recognizes placeholders if they
are uppercase. Use uppercase for all placeholders.
Recent synopsis changes move from literal code blocks to
[RST line blocks]. This does not translate well to HTML: it's not
rendered in monospace, so aligment is lost. Additionally, we don't
get syntax highlighting in HTML, which adds differences to our code
samples which are highlighted.
We hard-wrap synopsis lines (like code blocks). To align continuation
lines in manpages we need [backslashes in weird places]. Combined with
the **, *, and `` markup, it's a bit hard to get the alignment right.
Fix these by moving synopsis sources back to code blocks and compute
HTML syntax highlighting and manpage markup with a custom Sphinx
extension.
The new Pygments lexer can tokenize a synopsis and assign the various
highlighting roles, which closely matches fish's syntax highlighing:
- command/keyword (dark blue)
- parameter (light blue)
- operator like and/or/not/&&/|| (cyan)
- grammar metacharacter (black)
For manpage output, we don't project the fish syntax highlighting
but follow the markup convention in GNU's man(1):
bold text type exactly as shown.
italic text replace with appropriate argument.
To make it easy to separate these two automatically, formalize that
(italic) placeholders must be uppercase; while all lowercase text is
interpreted literally (so rendered bold).
This makes manpages more consistent, see string-join(1) and and(1).
Implementation notes:
Since we want manpage formatting but Sphinx's Pygments highlighing
plugin does not support manpage output, add our custom "synopsis"
directive. This directive parses differently when manpage output is
specified. This means that the HTML and manpage build processes must
not share a cache, because the parsed doctrees are cached. Work around
this by using separate cache locations for build targets "sphinx-docs"
(which creates HTML) and "sphinx-manpages". A better solution would
be to only override Sphinx's ManualPageBuilder but that would take a
bit more code (ideally we could override ManualPageWriter but Sphinx
4.3.2 doesn't really support that).
---
Alternative solution: stick with line blocks but use roles like
:command: or :option: (or custom ones). While this would make it
possible to produce HTML that is consistent with code blocks (by adding
a bit of CSS), the source would look uglier and is harder to maintain.
(Let's say we want to add custom formatting to the [|] metacharacters
in HTML. This is much easier with the proposed patch.)
---
[RST line blocks]: https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html#line-blocks
[backslashes in weird places]: https://github.com/fish-shell/fish-shell/pull/8626#discussion_r782837750
The next commit will load another of our Python extensions from a
separate file. That extension will contain more than just a Pygments
lexer, so instead of using a function that can only load a lexer,
just import from the module to keep things consistent.
Keywords and options recently got dedicated highlighting roles in
b3626d48e (Highlight keywords differently, 2021-02-04) and
711796ad1 (Highlight options differently, 2021-10-19)
but still default to "command" and "parameter", respectively.
The dedicated roles were not colored by our CSS theme,
which makes a "test -f foo.txt" look weird:
- "test" is dark blue (since it's a command)
- "foo.txt" is light blue (since it's a parameter)
- "-f" is black (weird!)
The CSS theme doesn't support configuration, so the dedicated
highlighting roles should always default to their fallback
options. Make it so.
This corrects what looks like wrong alignment of some synopsis lines.
(I think the alignment is not a bad idea but it makes us do more
manual work, maybe we can automate that in future. We still need to
figure out how to translate it to HTML.)
"man -l build/user_doc/man/man1/history.1" before:
string match [-a | --all] [-e | --entire] [-i | --ignore-case]
[-r | --regex] [-n | --index] [-q | --quiet] [-v | --invert]
PATTERN [STRING…]
and after:
string match [-a | --all] [-e | --entire] [-i | --ignore-case]
[-r | --regex] [-n | --index] [-q | --quiet] [-v | --invert]
PATTERN [STRING…]
Also make the lines align the same way in the RST source by carefully
choosing the position of the backslash. I'm not sure why we used
two backslashes per line. Use only one; this gives us no choice
of where to put it so both source and man page output are aligned.
Change tabs to spaces to make the alignment in the source work.
The ellipsis is a grammar metacharacter, just like the []()|.
Write *FOO*… instead of *FOO…*, so the ellipsis is not underlined
in the man page. Not super sure about this one.
This matches the style in man(1) (except that we use the … ligature).
A previous iteration did the reverse (never use a space before the
ellipsis). That would be a smaller change.
We use plural "*OPTIONS*" more often than "*OPTION*...", so let's do
that everywhere.
In some other places where we do have an ellipsis, make sure to use
singular, since the ellipsis already means repetition. This change
is incomplete, and I'm not sure if this is worth it, since it's
subjective, so I might drop it.
Correct the grammar by moving the options after the command argument.
Also group the -c/--command and -p/--path pairs, to convey that the
short and long variants are equivalent.
While at it, consolidate the -C/--do-complete forms, like we usually
do.
One synopsis misrenders as
set [options] VARIABLE*[*INDICES]… VALUES…
Add a missing backslash to fix that. Also go back to uppercase
because I'm not sure why this was changed to lowercase.
Finally, remove the spurious ellipsis after VARIABLE[INDICES].
This element cannot be repeated. Multiple index values and ranges
can be specified but that's already implied by the plural INDICES.
For alteration we usually use "(a | b)", not "{a | b}".
While at it, instead of writing 4/6 subcommands in one line, write them
on separate lines, so it's very obvious that all these are separate
subcommands. We mainly use the (a | b) syntax for long/short options.
The -- is not special here and we don't mention it in other synopses.
It was originally added for a good reason in 98449fec5 (fix `math`
regression, 2017-07-14), along this addition to math.rst:
> You should always place a `--` flag separator before the expression. [...]
However, since 56d913453 (Cache math expressions, 2017-08-24) that
line was changed to
> You don't need to use `--` before the expression even if it begins with a minus sign [...]
Previously, when we got an unknown option with --ignore-unknown, we
would increment woptind but still try to read the same contents.
This means in e.g.
```
argparse -i h -- -ooo -h
```
The `-h` would also be skipped as an option, because after the first
`-o` getopt reads the other two `-o` and skips that many options.
This could be handled more extensively in wgetopt, but the simpler fix
is to just skip to the next argv entry once we have an unknown option
- there's nothing more we can do with it anyway!
Additionally, document this and clearly explain that we currently
don't transform the option.
Fixes#8637
Unfortunately the normal font families like "sans-serif" and
"monospace" are basically broken because the browser defaults are
decades old.
TODO: Inline code is barely distinguishable.
Unfortunately this removes the index also from the sidebar in other pages. This makes it basically inaccessible.
Maybe there is a way to not show it in the list at the bottom, but this isn't it. Maybe a manual list of pages instead of reusing the TOC?
This reverts commit b5a95317f0.
Use the remaining_to_disclose count to determine if all completions
are shown (allows consistent behavior between short and long completion
lists).
Closes#8485
Currently,
set -q --unpath PATH
simply ignores the "--unpath" bit (and same for "--path").
This changes it, so just like exportedness you can check pathness.
Unless we use "complete --require-parameter", we must say "-w32",
not "-w 32", because the second "32" is a positional argument.
Notably, old options do not have this behavior, which is a bit weird,
see #8465
Taken from a discussion in #8459
* fish_key_reader: Simplify default output
It now only prints the bind statement. Timing information and such is
relegated to a separate "verbose" mode.
* Adjust fish_key_reader docs
* Adjust tests
Unlike in other shells, for-loops do not set $status if
1. the loop count is zero, or if
2. the loop body consists of only commands like "set" that don't
set $status.
POSIX for-loops always set an exit status (they set 0 if no loop
iterations). Following that would be awkward because it would add a
lot of complexity in combination with the 2 special cases above.
Document that "for" behaves the same as "set": it will pass through
existing $status, and also the last child's $status.
See the discussion in #8409
Adding the underline in the list of sections makes them bleed
together, making it hard to discern where one ends and the other
begins.
In the body of the text we don't have that issue - multiple links are
rarely next to each other.
Fixes#8439
Unfortunately, currently :program: doesn't link to the program's page.
So we use the old-school :ref: again where we should link, i.e. for
everything that's not the program the current page is about.
Fixes#8438
Documents like fish-tutorial don't need the NAME portion below.
(they also shoudln't be in section 1! These should be section 7,
they aren't for programs.)
the manpage writer will skip NAME if given an empty sstring as
the description.
--
FISH-TUTORIAL(1) fish-shell FISH-TUTORIAL(1)
NAME
fish-tutorial - fish-shell tutorial
This fixes the indentation problem for the SYNOPSIS section by not
inserting the :: literal block. Format it the same way Sphinx does
their own manpages for commands.
Use more semantic markup, like :command:, so that commands are
highlighted in the man pages.
Split by sentence to give `man` a chance to ascertain lines.
Long-term, it should be possible to teach Sphinx to turn :command:s
into references and get us automatic links to articles for matching
cmds/*.
This introduces a new variable, $fish_color_option, that can be used
to highlight options differently.
Options are tokens starting with `-`, but only up to (and including!)
the first `--`.
Fixes#8292.
This uses a bit of javascript to add copy buttons, so you can directly
copy all the code in a given block to the clipboard!
For codeblocks without prompts, it just copies all the code, for
blocks with prompts, it copies all the lines after prompts, under the
assumption that that's the code to be executed.
It would give you *all* the lines, so the output wouldn't be
interleaved like it is in the html, but good enough.
The buttons appear on hover, so they aren't usable on phones, but
since you won't really have a clipboard on phones and I have no idea
how to make them not always in front of the text otherwise: Eh.
I'm not in love with the javascript here, but it'll do.
* commandline: Add --is-valid option to query whether it's syntactically complete
This means querying when the commandline is in a state that it could
be executed. Because our `execute` bind function also inserts a
newline if it isn't.
One case that's not handled right now: `execute` also expands
abbreviations, those can technically make the commandline invalid
again.
Unfortunately we have no real way to *check* without doing the
replacement.
Also since abbreviations are only available in command position when
you _execute_ them the commandline will most likely be valid.
This is enough to make transient prompts work:
```fish
function reset-transient --on-event fish_postexec
set -g TRANSIENT 0
end
function maybe_execute
if commandline --is-valid
set -g TRANSIENT 1
commandline -f repaint
else
set -g TRANSIENT 0
end
commandline -f execute
end
bind \r maybe_execute
```
and then in `fish_prompt` react to $TRANSIENT being set to 1.
That `find` example is a bit dated and awkward, and doesn't really fit
the section.
We also don't want to point people to `?` because we want to remove it.
* Add `set --function`
This makes the function's scope available, even inside of blocks. Outside of blocks it's the toplevel local scope.
This removes the need to declare variables locally before use, and will probably end up being the main way variables get set.
E.g.:
```fish
set -l thing
if condition
set thing one
else
set thing two
end
```
could be written as
```fish
if condition
set -f thing one
else
set -f thing two
end
```
Note: Many scripts shipped with fish use workarounds like `and`/`or`
instead of `if`, so it isn't easy to find good examples.
Also, if there isn't an else-branch in that above, just with
```fish
if condition
set -f thing one
end
```
that means something different from setting it before! Now, if
`condition` isn't true, it would use a global (or universal) variable of
te same name!
Some more interesting parts:
Because it *is* a local scope, setting a variable `-f` and
`-l` in the toplevel of a function ends up the same:
```fish
function foo2
set -l foo bar
set -f foo baz # modifies the *same* variable!
end
```
but setting it locally inside a block creates a new local variable
that shadows the function-scoped variable:
```fish
function foo3
set -f foo bar
begin
set -l foo banana
# $foo is banana
end
# $foo is bar again
end
```
This is how local variables already work. "Local" is actually "block-scoped".
Also `set --show` will only show the closest local scope, so it won't
show a shadowed function-level variable. Again, this is how local
variables already work, and could be done as a separate change.
As a fun tidbit, functions with --no-scope-shadowing can now use this to set variables in the calling function. That's probably okay given that it's already an escape hatch (but to be clear: if it turns out to problematic I reserve the right to remove it).
Fixes#565
