`escape_code_length()` was converted from returning a `size_t` to
returning a `maybe_t<size_t>` but that subtly broke all existing call
sites by forcing all input to go through the slow path of assuming a
zero-length escape sequence was found.
This is because all callers predicated their next action on what amounts
to `if (escape_code_length(...))` which would correctly skip the slow
path when `escape_code_length` returned zero, but after the conversion
to `maybe_t` contained not `maybe_t::none()` but rather
`maybe_t::some(0)` due to coercion of the result from the `size_t` local
`esc_seq_len` to the `maybe_t<size_t>` return value - which, when
coerced to a boolean returns *true* for `maybe_t::some(0)` rather than
false.
The regression was introduced in 7ad855a844
and did not ship in any released versions so no harm, no foul.
This is required for the usage of placement new. Not an issue for fish
as it gets picked up from elsewhere, but it lets one use it in a C++
test directly this way.
As functions know where they are loaded from now, there is no point in
them being marked as loaded from a temporary file that has been removed.
Source the function via a redirect instead.
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 $TRANSIENT being set to 1.
That `find` example is a bit dated and awkward, and doesn't really fit
the section.
We also don't want to point people to `?` because we want to remove it.
support for ping from iputils (version 20210202)
support for ping from inetutils (version 2.1)
support for ping from busybox (version 1.33.1)
support for ping from FreeBSD and macOS (by @juntuu)
Because we are, ultimately, interested in how many cells a string
occupies, we *have* to handle carriage return (`\r`) and line
feed (`\n`).
A carriage return sets the current tally to 0, and only the longest
tally is kept. The idea here is that the last position is the same as
the last position of the longest string. So:
abcdef\r123
ends up looking like
123def
which is the same width as abcdef, 6.
A line feed meanwhile means we flush the current tally and start a new
one. Every line is printed separately, even if it's given as one.
That's because, well, counting the width over multiple lines
doesn't *help*.
As a sidenote: This is necessarily imperfect, because, while we may
know the width of the terminal ($COLUMNS), we don't know the current
cursor position. So we can only give the width, and the user can then
figure something out on their own.
But for the common case of figuring out how wide the prompt is, this
should do.
Without escapes.
The new option is a bit cheesy, but "width" isn't as expressive and
requires an argument.
Maybe we want "pad" to also require --visible?
