I generated nerdfonts_data.rs with this shell script; it uses `i_all.sh`
from the nerdfonts repo to get the base mapping:
```
source ./lib/i_all.sh
echo "//! Data mapping nerd font symbol names to their char codepoints"
echo "pub const NERD_FONT_GLYPHS: &[(&str, char)] = &["
for var in "${!i@}"; do
# trim 'i_' prefix
glyph_name=${var#*_}
glyph_char=${!var}
glyph_code=$(printf "%x" "'$glyph_char'")
echo "(\"$glyph_name\", '\u{$glyph_code}'), // $glyph_char"
done
echo "];"
```
Then intent is to use it in wezterm:
```
local wezterm = require 'wezterm'
wezterm.log_info(wezterm.nerdfonts.dev_mozilla)
```
Built using:
```
./FontForge-2020-11-07-21ad4a1-x86_64.AppImage --script $PWD/font-patcher "$PWD/src/unpatched-fonts/NerdFontsSymbolsOnly/NerdFontsSymbolsOnly Template 1000 em.ttf" --powerline --use-single-width-glyphs -out /tmp/nerd-fonts-out --fontawesome --fontawesomeextension --fontlinux --octicons --codicons --powersymbols --powerline --powerlineextra --mdi --weathericons
```
which is everything *except* Pomicons at the time of writing, pending
clarifications of its distribution license
(https://github.com/ryanoasis/nerd-fonts/issues/266)
refs: https://github.com/wez/wezterm/issues/1521
This action causes the active workspace for the gui to change.
If the name is omitted a random name will be generated.
If the workspace doesn't exist, it will be be created.
The optional spawn parameter can be used to launch a specific
program into the new workspace; if omitted, the default prog
will be used.
The gui only supports a single active workspace. Switching workspaces
will repurpose existing gui windows and re-assign them to windows
in the new workspace, adjusting their size to fit those windows,
spawning new windows or closing unused windows as required.
The gui now exits when there are no panes in the active workspace,
rather than no panes at all.
refs: #1531
Tidies up some code duplication within the mux protocol handler.
Move some of the logic into Mux, remove legacy Spawn Pdu to reduce
more duplication.
I want to dedup some of the similar logic that exists in the gui
spawn implementation as well in a follow up.
The issue is that we work hard to match the keys pre-composition,
but for French and Norwegian layouts ALT-number are valid,
useful punctuation keys. It's awkward to make exceptions for
ALT keys when matching assignments, especially on macOS, and
the simplest thing to do is simply to remove the assignments
and leave it to our users to add their own if they want them.
The ctrl-shift and cmd based assignments are generally much
easier to keep, because those key combinations are not widely
used default mappings on any keyboard layout.
refs: #1543
refs: #1542
refs: https://github.com/wez/wezterm/pull/1132
This resolves some issues with non-US layouts (French, Norweigan)
where ALT-number are important and useful punctuation that we were
otherwise blocking.
This new behavior seems consistent with eg: vte terminals on linux
when switching to a French layout.
refs: #1543
refs: #1542
`ScrollByPage` can accept non-integer values in the configuration.
This allows fractional page scrolling, such as by half a page.
The default remains the same, at 1 page.
If we know that the remote host is a unix system, and that it uses some
version of the posix shell, then we can adjust our command line to cd to
the requested directory (as set by OSC 7) and then exec the requested
command.
That's what SshDomain::assume_unix indicates and what this commit does.
This puts us in a better position for the future to be able
to configure whether we use wezterm, tmux or no multiplexing.
Today we allow wezterm or no multiplexing.
Add docs on this new setting.
refs: https://github.com/wez/wezterm/issues/1456
That top level config/src/lib.rs has been too big for too long.
Break it up a little.
(I recommend running `cargo clean` if you're updating across
this change to avoid a rust ICE with it cached on-disk state)
Previously, it would skip loading the initial config and allow
loading it later by using the reload hotkey. That reload behavior
was an accident!
Another problem with the old approach is that everything else was
set up as if the config had been loaded, which is now causing
confusion for code that wants to decide whether we are using
that configuration or not.
This commit formalizes the skip by remembering that state globally.
This change helps to simplify some special cases around command
line overrides as well, as well as allows cli overrides to take
effect when the user doesn't have a config file.
They have their own versions of these options, and logically it doesn't
make sense to use the default_prog from the `local` domain with a wsl
domain.
refs: #1242
This returns the default set of domains that would be populated
in the wsl_domains config. This is useful if you want to override
eg: the default_prog for specific domain(s), or want to otherwise
add additional variations on the default list.
When set, changes the default domain to the domain with the specified
name, which potentially affects the default program.
eg: default_domain = "WSL:Ubuntu-18.04" will cause the initial tab
to be spawned via WSL.
The idea is that we want to be able to spawn into wsl with the
convenience of a local domain, but without the awkwardness of
it having a different filesystem namespace.
It would also be great to be able to spawn a new tab or pane
in the same domain and pick up the cwd of the existing one.
The WslDomain allows the user to explicitly list WslDomains
and control eg: default shell, username and so on, but wezterm
will pre-fill a default list of domains based on the `wsl -l`
output that we were already using in the launcher menu.
The existing LocalDomain has been augmented to understand that
it may need to fixup a command invocation and that gives it
the opportunity to rewrite the command so that we can launch
it via `wsl.exe` and pass down the cwd and so on.
This same technique might be extensible to eg: docker instances
in the future.
This commit:
* Introduces `wsl_domains` config and its default list of wsl
distributions
* Creates LocalDomain instances from that list
* The launcher menu allows spawning a new tab via one of those domains
Using the new publish/discovery stuff from the past couple of commits,
if we can find a matching socket path for a running gui, and the
configuration is likely a match, then use the mux protocol to talk
to the already running gui and ask it to spawn the equivalent program
into the same process.
refs: https://github.com/wez/wezterm/discussions/1486
We need 100% of the info for it to work correctly, so this commit:
* Exposes the keyboard encoding mode via the Pane trait
* Adds the scan code to the RawKeyEvent
* Has the GUI perform the encoding if the keyboard is set that way
* Removes the basic encoder from termwiz in favor of the gui level one
The net result is that we bypass the Pane::key_up/Pane::key_down methods
in almost all cases when the encoding mode is set to win32-input-mode.
There is now a config option: allow_win32_input_mode that can be
used to prevent using this mode.
refs: #1509
* Allow selecting the first few rows by number
* Allow scrolling through long lists of items
* Add actions from key assignments to list
refs: #1485
refs: #1413
This commit adjusts the config parsing layer so that:
```
return {
keys = {
{key="a", ...}
}
}
```
is now treated as being implicitly the same as `key="phys:A"`.
You can explicitly use `key="mapped:a"` to use the post-keyboard-map
processed value of a key to trigger an assignment, rather than
the physical key location.
refs: #1483
When set, the cursor will change to this color during dead key
or leader key processing.
```lua
return {
colors = {
dead_key_cursor = "orange",
},
}
```
refs: #686
refs: #688
We only need to recompute when the tab content changes, or when
the window is resized, plus invalidations of the shape cache
of texture atlas filling up.
Hover events don't need to re-shape.
We can now also place the tab bar at the bottom of the screen again.
This commit adds a CSS box model inspired element / layout
facility, and replaces the hand implemented fancy tab bar
element render.
This makes the code for fancy tab bar much easier to read
and update.
The right status area now expands to the full height of the
tab bar area, and uses a line height of 2.0, which makes
it line up nicely in the tab bar.
This adds string serialization for the keycode and modifiers as
used in the config.
We can't simply tell the base types to serialize in this form because
we may serialize and pass those via the mux protocol and the default
derived serializers are more efficient for that purpose.
This allows:
```lua
local wezterm = require 'wezterm'
return {
keys = {
{key="a", mods="ALT", action=wezterm.action{SendKey={key="b"}}}
},
}
```
to parse: previously, wrapping `SendKey` in `wezterm.action` would fail
to round-trip the the `SendKey` and lead to an error loading the
config.
Rather than hardcode a fixed default value in the config crate, define
the default as optional and leave it to the font crate to compute
the value.
This is a step towards allow introducing system dependent GUI related
code to resolve/understand the title font: we can't put that directly
in the config crate.
There was a discrepancy between leaving it out of the config
and having it partially initialized; fix that up.
Make the default title font size larger on !Windows, as it
looks a bit better.
We might need to make this larger size mac specific.
refs: #1180
Add `get_foreground_process_name` to both Pane and the lua wrapper.
Add `foreground_process_name` and `current_working_dir` fields to
`PaneInformation`. In order for those to be dynamically fetched,
switch the lua conversion for `PaneInformation` to be a UserData
with field access methods. It's a little more verbose but allows
us to lazily compute these two new fields.
refs: https://github.com/wez/wezterm/discussions/1421
refs: https://github.com/wez/wezterm/issues/915
refs: https://github.com/wez/wezterm/issues/876
This is really a timing issue: if shift-click extension of the mouse
selection is used, the user may release the mouse button slightly
after the SHIFT key (which is fine) or vice versa (which was not
previously matched)
refs: #1204
This commit expands quick select mode so that you can trigger it
with distinct sets of patterns (eg: urls on one key assignment,
hashes on a different key assignment), different alphabets,
and lastly, the option to perform a different action from
the default copy action.
You can pair this with `action_callback` to run lua code to
do something with the selected text.
This commit also adds `wezterm.open_with`, a helper function
for opening documents/URLs.
refs: #846
refs: #1362
Adds some plumbing to allow the GUI to implement a download handler
and connect that up for iterm2 image/file transfers that have their
inline property set to false.
Previously we'd just log an error.
Now we will by default download the file to the user's download
directory.
This behavior can be turned off via the new `allow_download_protocols`
configuration setting.
File transfers can be initiated on a remote host via the
https://iterm2.com/utilities/it2dl script.
When the download completes, a toast notification is shown that will
open the file when clicked.
refs: https://github.com/wez/wezterm/discussions/1450
`wezterm.font` and `wezterm.font_with_fallback` can now specify
harfbuzz_features and freetype load/render target and flags as
options on a per-font basis.
This allows you to do things such as adjust shaping (eg: ligatures) or
rendering (eg: disable bitmaps, or adjust hinting) for a single font in
a fallback rather than globally for all fonts.
This got lost somewhere along the way.
Importantly, we need to explicitly set the pty to use invalid stdio
handles for the spawned child in order to avoid a weird situation
where eg: cmd or powershell would end up writing to the log file
despite it being spawned into its own PTY.
refs: #1358
This is a fairly far-reaching commit. The idea is:
* Introduce a unicode_version config that specifies the default level
of unicode conformance for each newly created Terminal (each Pane)
* The unicode_version is passed down to the `grapheme_column_width`
function which interprets the width based on the version
* `Cell` records the width so that later calculations don't need to
know the unicode version
In a subsequent diff, I will introduce an escape sequence that allows
setting/pushing/popping the unicode version so that it can be overridden
via eg: a shell alias prior to launching an application that uses a
different version of unicode from the default.
This approach allows output from multiple applications with differing
understanding of unicode to coexist on the same screen a little more
sanely.
Note that the default `unicode_version` is set to 9, which means that
emoji presentation selectors are now by-default ignored. This was
selected to better match the level of support in widely deployed
applications.
I expect to raise that default version in the future.
Also worth noting: there are a number of callers of
`unicode_column_width` in things like overlays and lua helper functions
that pass `None` for the unicode version: these will assume the latest
known-to-wezterm/termwiz version of unicode to be desired. If those
overlays do things with emoji presentation selectors, then there may be
some alignment artifacts. That can be tackled in a follow up commit.
refs: #1231
refs: #997
* mux: unzoom when switching panes
Add `unzoom_on_switch_pane` config option:
When switching to another pane with ActivatePaneDirection, if the
current pane is zoomed, unzoom and then switch instead of doing nothing.
* Apply suggestions from code review
Co-authored-by: Wez Furlong <wez@wezfurlong.org>
The issue seems to correlate with fractional pixels produced
by 0.5cell padding, so let's round down to avoid the fraction.
refs: https://github.com/wez/wezterm/issues/1228
Was mistakenly trying to use the windows font because of negative logic.
Tidy up, and prefer the gnome default theme font (Cantarell), but fall
back to DejaVu Sans.
This commit introduces the `Dimension` type which allows specifying
a value in a variety of units; pixels, points, cells, percent.
`Dimension` needs contextual information to be evaluated as pixel
values, which makes resolving the value from the config slightly
more of a chore.
However, this type allows more flexible configurations that scale
with the font size and display dpi.
refs: #1124, #291, #195
Avoid accidentally scaling the tab bar when using IncreaseFontSize.
Use a "better" default title font based on the platform.
Avoid a gap between bottom of tab button and dividing line at
certain font sizes.
`use_fancy_tab_bar` switches to an alternate rendering of the tab
bar that uses the window_frame config to get a proportional
title font to use to render tabs, as well as rendering a few
additional elements to space out and make the tabs feel more
like tabs.
Computing the number of tabs doesn't respect the alternate font
at this time.
Formatted tab item foreground and background colors are also
not respected at this time.
refs: #1180
* Trigger a paint immediately from invalidate if not throttled
* Otherwise defer the other events until we're about to sleep for xcb
events, which should maximize the coalesce around resize/expose events
refs: #1051
This makes the comparison in https://github.com/wez/wezterm/issues/544
work for me on mac, linux (x11, wayland) and also on Windows but
only using WGL.
It looks like we can use the proper colorspace on all targets
except for ANGLE EGL. For whatever reason, the combination of
glium and ANGLE EGL on windows over-gamma corrects.
AFAICT, the framebuffer and perhaps the surfaces it creates
don't indicate srgb support, and whatever combination of status
they return tickles glium's srgb stuff the wrong way.
I think the "solution" is just to directly use WGL by default.
EGL was on by default because it tended to be more survivable
when graphics card drivers were updated, but the last couple
of times I updated mine it still killed wezterm anyway.
refs: #544
This size seems to be ~sweet spot for `time cat bigfile`, cutting the
time in half from the prior value. Making the buffer smaller doesn't
improve things, nor does making it bigger; this is balancing the latency
of applying the update to the model with the back-pressured parsing
latency.
I'm not sure if this is needed now that we have a single draw call, but
based on the history and the nuance of different gl/driver/os quirks it
feels like a good idea to keep this option in the back pocket.
Previously, we'd use a 1MB buffer both to read the output from the
associated pty (blocking), and the same size buffer again to do the
non-blocking read on top of that.
For pathological cases (eg: cat 100MB+ files), we could build a
resulting `Vec<Action>` with over 1mm entries and it could take as much
as 100ms to apply those actions to the terminal model.
This meant that the output could stutter/lag and appear to be processed
more slowly.
This commit introduces a configuration value for the buffer size for the
second stage, and makes it 10KB in size. This helps to constrain the
size of the Action vec and keeps the incremental processing costs down,
while still managing the same throughput.
This commit causes a window-config-reloaded event to trigger
when the appearance (dark/light mode) is changed on macos.
It also arranges to propagate the window level config to newly
spawned panes and tabs, created both via the gui and via the
CLI/mux interface.
refs: https://github.com/wez/wezterm/issues/894
refs: https://github.com/wez/wezterm/issues/806
This allows window-level config overrides to apply
to panes contained within the window.
For instance, this allows setting a window-level
color scheme.
I added this originally thinking that it would make it easier to resolve
https://github.com/wez/wezterm/issues/695 and to integrate wgpu support,
but it's the cause of https://github.com/wez/wezterm/issues/922 so let's
take it out and more directly connect the window events to those in the
terminal.
This commit likely breaks mac and windows; pushing it so that I can
check it out and verify on those systems.
opentype allows a font to have a weight in the range 0-1000.
MacOS has its own concept of symbolic weight names and opentype
values that is a slightly different scale of boldness to Windows
and Linux.
That means that Medium could be a different range of opentype
weight values depending on the system.
To further complicate things, the font designer can name their
variant with any name they like and assign it an arbitrary
opentype weight value.
For the Operator Mono font, it has Book variant with opentype
weight 325 and a Light variant with an opentype weight of 300.
wezterm was considering these both to have `FontWeight::Light` because
that's how those values were bucketed, which results in amibiguity in
resolve the font and frustration in not being able to access one of the
variants.
This commit changes the `FontWeight` type to now hold the unambiguous
opentype weight value, and to define some symbolic aliases for
some specified weights.
When serializing, if the weight matches a symbolic alias, then that
name will be used in the canonical name (eg: as listed via ls-fonts).
Otherwise, the numeric value will be used.
When parsing the font configuration, wezterm will allow both symbolic
and numeric values.
This allows all of the Operator Mono variants to be referenced
unambiguously, although some variants have to be specified via the
numeric weight:
```
wezterm.font("Operator Mono", {weight=275, stretch="Normal", italic=false}) -- /Users/wez/.fonts/OperatorMono-XLight.otf, FontDirs
wezterm.font("Operator Mono", {weight="Light", stretch="Normal", italic=false}) -- /Users/wez/.fonts/OperatorMono-Light.otf, FontDirs
wezterm.font("Operator Mono", {weight=325, stretch="Normal", italic=false}) -- /Users/wez/.fonts/OperatorMono-Book.otf, FontDirs
wezterm.font("Operator Mono", {weight="DemiLight", stretch="Normal", italic=false}) -- /Users/wez/.fonts/OperatorMono-Medium.otf, FontDirs
wezterm.font("Operator Mono", {weight="Regular", stretch="Normal", italic=false}) -- /Users/wez/.fonts/OperatorMono-Bold.otf, FontDirs
```
https://github.com/wez/wezterm/issues/849#issuecomment-873454483
This simplifies it a bit and exposes the config via the config file;
the following options are possible, each one specifies a color
```lua
return {
window_frame = {
inactive_titlebar_bg = "",
active_titlebar_bg = "",
inactive_titlebar_fg = "",
active_titlebar_fg = "",
inactive_titlebar_border_bottom = "",
active_titlebar_border_bottom = "",
button_fg = "",
button_bg = "",
button_hover_fg = "",
button_hover_bg = "",
}
}
```
refs: https://github.com/wez/wezterm/issues/761
Adds a `ShowDebugOverlay` key assignment that will create a tab
overlay that shows a limited number of recently logged events.
refs: https://github.com/wez/wezterm/issues/641
This commit introduces the knowledge about whether a font is
scalable or was using bitmap strikes (eg: color emoji bitmaps).
Then that information is used to help figure out whether and
how to scale a glyph.
refs: https://github.com/wez/wezterm/issues/685
Previously, we used `git describe --tags` to produce a version number
for non-released builds derived from the most recent tag + some info
such as the number of commits since that tag and then `g{HASH}`.
That always confuses people because the date portion at the front
looks old (it is typically the previous release) and the hash at
the end has that `g` in it.
This commit simplifies both the tag name used when making a release
and the computed version number take the date/time from the current
commit, and then append the hash. That way the version number always
corresponds to a commit.
This scheme doesn't help detect situations where the commit is
dirty, but I don't think the old one would have helped with that
either.
* Make alphabet and patterns configurable
* add docs
* Enhance scrollback search to support regex captures so that
searching for eg: `fo(o)` will select the last `o` in `foo`.
refs: https://github.com/wez/wezterm/issues/732
This is the first pass implementation, drawing on the alphabet logic
and default patterns from tmux-thumbs (thanks @fcsonline!).
ctrl-shift-space pops up the quick select overlay.
Typing the highlighted prefix will select the matching text and
copy it as though the `Copy` key assignment was used.
TODOs are to make the alphabet and patterns configurable, as well
as write up some docs.
refs: #732
This tidies up how we pass the ssh config to the connection ui
logic, by moving the ssh_config setup to the two callers.
A couple of notable adjustments:
* SshDomain::username is now optional; it will default to the
values computed by the ssh config file loader
* no_agent_auth value wasn't hooked up to anything, but now it is
refs: https://github.com/wez/wezterm/issues/730
Now that all platforms know whether the system fallbacks
covered the requested glyph range, it is reasonable to
restore the configuration error window to advise the user
if they are missing fonts for the text they want to display.
refs: https://github.com/wez/wezterm/issues/671
One of the default key assignments was registered as `SUPER+SHIFT+{`
which worked on macOS, but on Linux, would never match because the
keypress over there was (correctly) reporting as `SUPER+{`.
I originally thought that the user reported issue was a linux
normalization problem, but in looking deeper, the issue is really
that macos is doing something funky!
On macos we collect the interpreted key event as a string, and also
the interpretation of that event without any modifiers applied.
For letters this means that eg: `ALT-l` reports as `¬` for the
processed string and `l` for the unmodified string. That's good!
However, for punctuation we get a backwards result: SUPER+SHIFT+[
produces `[` for the processed text and `{` for the unmodified
text!
This commit tries to detect this, using a heuristic that is
potentially bad on non-US layouts: if both the processed and
unmodified strings are punctuation then we bias to the unmodified
version.
With that change, that key press is correctly reported as `SUPER+{`,
and we can fix the key assignment registration to reflect that.
I quickly checked the behavior of pressing that same physical key
combination with a DEU layout active, and it appears that the unmodified
stuff is also flipped there; we get a lower-case version of something
that I think should be uppercase. This commit doesn't change that
behavior:
```
key_event KeyEvent { key: Char('ü'), modifiers: NONE,
raw_key: Some(Char('Ü')),
raw_modifiers: SHIFT | SUPER,
raw_code: Some(33),
repeat_count: 1, key_is_down: true }
```
refs: https://github.com/wez/wezterm/issues/601
This replicates `last-window` in tmux. To pull this off, I
deliberately store the last tab whenever I'm activating a new one or
spawning a new one. I had to do this explicitly rather than hooking
set_active, because we end up setting the active tab briefly for some
common operations like moving a tab.
Default `allow_square_glyphs_to_overflow_width="WhenFollowedBySpace"`,
and expand its meaning from mostly square glyphs to glyphs that are
also wider than they are tall.
refs: https://github.com/wez/wezterm/issues/565
CI got broken by the termwiz release. This commit teaches the
various `git describe --tags` calls to filter to the wezterm
tags which all start with the year. We're match `20*` which should
be good for the next 79 years.
I've removed the vergen dependency as there was no way to teach it
to do the equivalent matching, and it wasn't a terrible burden
to just inline the git describe call anyway.
The previous behavior was to always treat ctrl-alt as altgr on Windows,
this has been done to better support altgr through a VNC session,
but this is very unintuitive when you don't need this behavior.
ref: #472
I'm calling it a temporary defeat on the shaping changes;
this commit effectively reverts the series of changes made
to support slicing up ligatures like `->` when the cursor
moves through them.
They've introduced so many issues and I've spent hours
that haven't resulted in a complete solution, so I've
disabled those changes by putting them behind a boolean
option.
I'll revisit them after I've cut the next release.
refs: https://github.com/wez/wezterm/issues/478
Queries the system battery information and returns an array of
battery information.
Each element is a lua table with the following entries:
* state_of_charge: expressed as percents
* vendor: the battery manufacturer
* model: the battery model
* serial: the battery serial number
* time_to_full: how long until the battery is full
* time_to_empty: how long until the battery is empty
* state: "Charging", "Discharging", "Empty", "Full", "Unknown"
I haven't run this on a system with a battery yet, so I'm holding
off from showing an example until I've got a work one.
refs: https://github.com/wez/wezterm/issues/500
As explained in the docs included in this commit, ideally this
wouldn't be needed, but due to a long-standing hinting bug in
freetype <https://gitlab.freedesktop.org/freetype/freetype/-/issues/761>
it seems most expedient to just render our own block glyphs,
so that's what this does!
refs: #433
This commit expands on the prior commits to introduce the concept
of per-window configuration overrides.
Each TermWindow maintains json compatible object value holding
a map of config key -> config value overrides.
When the window notices that the config has changed, the config
file is loaded, the CLI overrides (if any) are applied, and then
finally the per-window overrides, before attempting to coerce
the resultant lua value into a Config object.
This mechanism has some important constraints:
* Only data can be assigned to the overrides. Closures or special
lua userdata object handles are not permitted. This is because
the lifetime of those objects is tied to the lua context in which
they were parsed, which doesn't really exist in the context of
the window.
* Only simple keys are supported for the per-window overrides.
That means that trying to override a very specific field of
a deeply structured value (eg: something like `font_rules[1].italic = false`
isn't able to be expressed in this scheme. Instead, you would
need to assign the entire `font_rules` key. I don't anticipate
this being a common desire at this time; if more advance manipulations
are required, then I have some thoughts on an event where arbitrary
lua modifications can be applied.
The implementation details are fairly straight-forward, but in testing
the two examplary use cases I noticed that some hangovers from
supporting overrides for a couple of font related options meant that the
window-specific config wasn't being honored. I've removed the code that
handled those overrides in favor of the newer more general CLI option
override support, and threaded the config through to the font code.
closes: #469closes: #329
`wezterm`, `wezterm-gui` and `wezterm-mux-server` now all support
a new `--config name=value` CLI option that can be specified
multiple times to supply config overrides.
Since there isn't a simple, direct way to update arbitrary fields
of a struct in Rust (there's no runtime reflection), we do this
work in lua.
The config file returns a config table. Before that is mapped
to the Rust Config type, we have a new phase that takes each
of the `--config` values and applies it to the config table.
For example, you can think of configuration as working like this
if wezterm is started as `wezterm --config foo="bar"`:
```lua
config = load_config_file();
config.foo = "bar";
return config;
```
The `--config name=value` option is split into `name` and `value`
parts. The name part is literally concatenated with `config` in
the generated lua code, so the name MUST be valid in that context.
The `value` portion is literally inserted verbatim as the rvalue in the
assignment. Not quoting or other processing is done, which means
that you can (and must!) use the same form that you would use in
the config file for the RHS. Strings must be quoted. This allows
you to use more complicated expressions on the right hand side,
such as:
```
wezterm --config 'font=wezterm.font("Fira Code")'
```
The overrides stick for the lifetime of the process; even if
you change the config file and reload, then the value specified
by the override will take precedence.
refs: https://github.com/wez/wezterm/issues/469
refs: https://github.com/wez/wezterm/issues/499
`exit_behavior = "Hold"` will keep the pane alive until explicitly
closed. More details in the docs that are part of this commit.
refs: https://github.com/wez/wezterm/issues/499
