Add vim/emacs modeline support by elmarco · Pull Request #44210 · zed-industries/zed

elmarco · 2025-12-05T12:33:45Z

Many editors such as vim and emacs support "modelines", a comment at the beginning of the file that allows the file type to be explicitly specified along with per-file specific settings

The amount of configurations, style and settings mapping cannot be handled in one go, so this opens up a lot of potential improvements.
I left out the possiblity to have "zed" specific modelines for now, but this could be potentially interesting.
Mapping the mode or filetype to zed language names isn't obvious either. We may want to make it configurable.

This is my first contribution to zed, be kind. I struggled a bit to find the right place to add those settings. I use a similar approach as done with editorconfig (merge_with_editorconfig). There might be better ways.

Closes #4762

Release Notes:

Add basic emacs/vim modeline support.

Supersedes #41899, changes:

limit reading to the first and last 1kb
add documentation
more variables handled
add Arc around ModelineSettings to avoid extra cloning
changed the way mode -> language mapping is done, thanks to modeline_aliases language config
drop vim ex: support
made "Local Variables:" handling a separate commit, so we can drop it easily
various code style improvements

ConradIrwin · 2025-12-12T04:57:38Z

Thanks for updating this.

Looking at the diff I'm struggling to see what we should do here; but we need to figure out how to make this feature much less invasive (like closer to 5 places in the codebases should know about modelines compared to ~55 files changed in this diff).

Random thoughts:

Given that we expect most files to not have modelines, could the buffer_store add them to a new global in add_buffer. If it only affects LanguageSettings, then maybe there's a new global in the language create, or it could go in the settings crate. (I don't think it should go in the existing settings store to avoid updating the settings store when a file is opened/closed). Then we could avoid passing them around everywhere.
Am I right in thinking modelines are only parsed when a file is opened? If you edit the modeline is there a way to get that change to show up?
For selecting language via modeline, I think for a v1 the mapping should live in the modeline crate and not be spread around every single langauge's definition.
The fn merge in merge_from_modeline should be the same as the merge_from_option used by the settings crate if you want to use that.

Does that make sense?

elmarco · 2025-12-16T20:18:15Z

I didn't manage to make this "global" approach. It looks fairly bad, as the modeline is attached to the buffer, having to look it up back from the file/buffer location is awkward and could easily leak. I will try a different approach where language_settings() is loaded more directly from buffer later.
yes, modelines are typically loaded during file open / reload
the mapping is alreay optional, I just added a few extra common mappings. I will split that in a different commit.
ok (along with updating existing editorconfig fn merge)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

This commit refactors how language settings are accessed across various crates. Instead of passing individual parameters like `language` and `file` explicitly, it now utilizes a more fluent builder pattern that can optionally take a `Buffer` or `BufferSnapshot` to infer these details. In a later patch, modeline settings support can be added seamlessly thanks to this refactoring. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Co-authored-by: Claude <noreply@anthropic.com> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

This will allow to configure vim/emacs modeline support. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Add an optional ModelineSettings to Buffer and BufferSnapshot. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

When the buffer is added on reloaded, parse the modelines and update the detected language. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Associated buffer's modeline is now merged. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

elmarco · 2026-01-15T10:58:20Z

@ConradIrwin have you had a chance to take another look? thanks

Now we need to take modeline into account they are not viable.

Buffers have their own language, so it's almost always an error to specify the buffer and the language (unless you're in a situation where you already did .language_at() or equivalent).

The builder methods were not composible (i.e. you had to be careful to call .language() after .buffer()), so it seems safer to not do that.

ConradIrwin · 2026-01-23T07:49:22Z

Sorry for the slow reply, and thank you for the improvements to the settings stuff!

I ended up building on what you had to take things further, but your change really clarified the problems with the old approach. In particular, now that modelines should be considered; it's a bug to look up settings on just the file, you need the buffer. Also, the order of the builder methods was subtly important: you needed to call .langauge() after .buffer() to avoid the buffer overriding the language. All in all it was less error prone to just add getters to the LanguageSettings.

From testing this seems to work as expected, so I'll merge when the tests are green.

elmarco · 2026-01-23T08:13:42Z

awesome! thanks @ConradIrwin

This reverts commit 4186e57.

@ConradIrwin

Reverts #44210 I am forced to revert this PR as it completely breaks release builds with the following panic: ``` thread 'main' (2648653) panicked at crates/rope/src/rope.rs:893:25: byte index 73 is not a char boundary; it is inside 'স' (bytes 71..74) of `কৰক</translation> <translation id="9216898458513705996">টেবসমূহ এই ডিভাইচত খোলা ` stack backtrace: 2026-01-23T15:37:48+01:00 INFO [node_runtime] using Zed managed Node.js at /Users/kubkon/Library/Application Support/Zed/node/node-v24.11.0-darwin-arm64 since system Node.js wasn't found on PATH: cannot find binary path 0: __rustc::rust_begin_unwind at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/std/src/panicking.rs:698:5 1: core::panicking::panic_fmt at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/core/src/panicking.rs:80:14 2: core::str::slice_error_fail_rt 3: core::str::slice_error_fail at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/core/src/str/mod.rs:69:5 4: core::str::traits::<impl core::slice::index::SliceIndex<str> for core::ops::range::Range<usize>>::index at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/core/src/str/traits.rs:248:21 5: <str as core::ops::index::Index<core::ops::range::Range<usize>>>::index at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/core/src/str/traits.rs:63:15 6: <rope::Chunks>::peek at /Users/kubkon/dev/zed/crates/rope/src/rope.rs:893:25 7: <rope::Lines>::next at /Users/kubkon/dev/zed/crates/rope/src/rope.rs:1111:45 8: <project::lsp_store::LspStore>::parse_modeline at /Users/kubkon/dev/zed/crates/project/src/lsp_store.rs:4570:43 9: <project::lsp_store::LspStore>::on_buffer_added at /Users/kubkon/dev/zed/crates/project/src/lsp_store.rs:4301:14 10: <project::lsp_store::LspStore>::on_buffer_store_event at /Users/kubkon/dev/zed/crates/project/src/lsp_store.rs:4166:22 11: <<project::lsp_store::LspStore>::on_buffer_store_event as core::ops::function::FnMut<(&mut project::lsp_store::LspStore, gpui::app::entity_map::Entity<project::buffer_store::BufferStore>, &project::buffer_store::BufferStoreEvent, &mut gpui::app::context::Context<project::lsp_store::LspStore>)>>::call_mut at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/core/src/ops/function.rs:166:5 12: <gpui::app::context::Context<project::lsp_store::LspStore>>::subscribe::<project::buffer_store::BufferStore, project::buffer_store::BufferStoreEvent, <project::lsp_store::LspStore>::on_buffer_store_event>::{closure#0}::{closure#0} at /Users/kubkon/dev/zed/crates/gpui/src/app/context.rs:111:44 13: <gpui::app::App as gpui::AppContext>::update_entity::<project::lsp_store::LspStore, (), <gpui::app::context::Context<project::lsp_store::LspStore>>::subscribe<project::buffer_store::BufferStore, project::buffer_store::BufferStoreEvent, <project::lsp_store::LspStore>::on_buffer_store_event>::{closure#0}::{closure#0}>::{closure#0} at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:2281:26 14: <gpui::app::App>::update::<(), <gpui::app::App as gpui::AppContext>::update_entity<project::lsp_store::LspStore, (), <gpui::app::context::Context<project::lsp_store::LspStore>>::subscribe<project::buffer_store::BufferStore, project::buffer_store::BufferStoreEvent, <project::lsp_store::LspStore>::on_buffer_store_event>::{closure#0}::{closure#0}>::{closure#0}> at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:818:22 15: <gpui::app::App as gpui::AppContext>::update_entity::<project::lsp_store::LspStore, (), <gpui::app::context::Context<project::lsp_store::LspStore>>::subscribe<project::buffer_store::BufferStore, project::buffer_store::BufferStoreEvent, <project::lsp_store::LspStore>::on_buffer_store_event>::{closure#0}::{closure#0}> at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:2279:14 16: <gpui::app::entity_map::Entity<project::lsp_store::LspStore>>::update::<(), gpui::app::App, <gpui::app::context::Context<project::lsp_store::LspStore>>::subscribe<project::buffer_store::BufferStore, project::buffer_store::BufferStoreEvent, <project::lsp_store::LspStore>::on_buffer_store_event>::{closure#0}::{closure#0}> at /Users/kubkon/dev/zed/crates/gpui/src/app/entity_map.rs:445:12 17: <gpui::app::context::Context<project::lsp_store::LspStore>>::subscribe::<project::buffer_store::BufferStore, project::buffer_store::BufferStoreEvent, <project::lsp_store::LspStore>::on_buffer_store_event>::{closure#0} at /Users/kubkon/dev/zed/crates/gpui/src/app/context.rs:111:22 18: <gpui::app::App>::subscribe_internal::<project::buffer_store::BufferStore, project::buffer_store::BufferStoreEvent, <gpui::app::context::Context<project::lsp_store::LspStore>>::subscribe<project::buffer_store::BufferStore, project::buffer_store::BufferStoreEvent, <project::lsp_store::LspStore>::on_buffer_store_event>::{closure#0}>::{closure#0} at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:964:25 19: <alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>> as core::ops::function::FnMut<(&dyn core::any::Any, &mut gpui::app::App)>>::call_mut at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/alloc/src/boxed.rs:2012:9 20: <gpui::app::App>::apply_emit_effect::{closure#0} at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:1407:21 21: <gpui::subscription::SubscriberSet<gpui::app::entity_map::EntityId, (core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>::retain::<<gpui::app::App>::apply_emit_effect::{closure#0}>::{closure#1} at /Users/kubkon/dev/zed/crates/gpui/src/subscription.rs:132:17 22: <alloc::collections::btree::map::BTreeMap<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>>::retain::<<gpui::subscription::SubscriberSet<gpui::app::entity_map::EntityId, (core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>::retain<<gpui::app::App>::apply_emit_effect::{closure#0}>::{closure#1}>::{closure#0} at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/alloc/src/collections/btree/map.rs:1177:37 23: <alloc::collections::btree::map::ExtractIfInner<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>, core::ops::range::RangeFull>>::next::<<alloc::collections::btree::map::BTreeMap<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>>::retain<<gpui::subscription::SubscriberSet<gpui::app::entity_map::EntityId, (core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>::retain<<gpui::app::App>::apply_emit_effect::{closure#0}>::{closure#1}>::{closure#0}, alloc::alloc::Global> at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/alloc/src/collections/btree/map.rs:2036:16 24: <alloc::collections::btree::map::ExtractIf<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>, core::ops::range::RangeFull, <alloc::collections::btree::map::BTreeMap<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>>::retain<<gpui::subscription::SubscriberSet<gpui::app::entity_map::EntityId, (core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>::retain<<gpui::app::App>::apply_emit_effect::{closure#0}>::{closure#1}>::{closure#0}> as core::iter::traits::iterator::Iterator>::next at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/alloc/src/collections/btree/map.rs:2002:20 25: <alloc::collections::btree::map::ExtractIf<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>, core::ops::range::RangeFull, <alloc::collections::btree::map::BTreeMap<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>>::retain<<gpui::subscription::SubscriberSet<gpui::app::entity_map::EntityId, (core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>::retain<<gpui::app::App>::apply_emit_effect::{closure#0}>::{closure#1}>::{closure#0}> as core::iter::traits::iterator::Iterator>::fold::<(), core::iter::traits::iterator::Iterator::for_each::call<(usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>), core::mem::drop<(usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>)>>::{closure#0}> at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/core/src/iter/traits/iterator.rs:2602:34 26: <alloc::collections::btree::map::ExtractIf<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>, core::ops::range::RangeFull, <alloc::collections::btree::map::BTreeMap<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>>::retain<<gpui::subscription::SubscriberSet<gpui::app::entity_map::EntityId, (core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>::retain<<gpui::app::App>::apply_emit_effect::{closure#0}>::{closure#1}>::{closure#0}> as core::iter::traits::iterator::Iterator>::for_each::<core::mem::drop<(usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>)>> at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/core/src/iter/traits/iterator.rs:828:14 27: <alloc::collections::btree::map::BTreeMap<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>>::retain::<<gpui::subscription::SubscriberSet<gpui::app::entity_map::EntityId, (core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>::retain<<gpui::app::App>::apply_emit_effect::{closure#0}>::{closure#1}> at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/alloc/src/collections/btree/map.rs:1177:46 28: <gpui::subscription::SubscriberSet<gpui::app::entity_map::EntityId, (core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>::retain::<<gpui::app::App>::apply_emit_effect::{closure#0}> at /Users/kubkon/dev/zed/crates/gpui/src/subscription.rs:130:21 29: <gpui::app::App>::apply_emit_effect at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:1405:14 30: <gpui::app::App>::flush_effects at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:1308:31 31: <gpui::app::App>::finish_update at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:830:18 32: <gpui::app::App>::update::<core::result::Result<(), anyhow::Error>, <gpui::app::App as gpui::AppContext>::update_entity<project::buffer_store::BufferStore, core::result::Result<(), anyhow::Error>, <project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}::{closure#0}::{closure#3}>::{closure#0}> at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:819:14 33: <gpui::app::App as gpui::AppContext>::update_entity::<project::buffer_store::BufferStore, core::result::Result<(), anyhow::Error>, <project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}::{closure#0}::{closure#3}> at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:2279:14 34: <gpui::app::async_context::AsyncApp as gpui::AppContext>::update_entity::<project::buffer_store::BufferStore, core::result::Result<(), anyhow::Error>, <project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}::{closure#0}::{closure#3}> at /Users/kubkon/dev/zed/crates/gpui/src/app/async_context.rs:65:13 35: <gpui::app::entity_map::WeakEntity<project::buffer_store::BufferStore>>::update::<gpui::app::async_context::AsyncApp, core::result::Result<(), anyhow::Error>, <project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}::{closure#0}::{closure#3}> at /Users/kubkon/dev/zed/crates/gpui/src/app/entity_map.rs:750:15 36: <project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}::{closure#0}::<i32> at /Users/kubkon/dev/zed/crates/project/src/buffer_store.rs:683:18 37: <gpui::app::context::Context<project::buffer_store::BufferStore>>::spawn::<<project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>>::{closure#0}::{closure#0}::<i32> at /Users/kubkon/dev/zed/crates/gpui/src/app/context.rs:244:52 38: <gpui::app::App>::spawn::<<gpui::app::context::Context<project::buffer_store::BufferStore>>::spawn<<project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>>::{closure#0}, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>>::{closure#0} at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:1532:44 39: <scheduler::executor::spawn_local_with_source_location::Checked<<gpui::app::App>::spawn<<gpui::app::context::Context<project::buffer_store::BufferStore>>::spawn<<project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>>::{closure#0}, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>>::{closure#0}> as core::future::future::Future>::poll at /Users/kubkon/dev/zed/crates/scheduler/src/executor.rs:393:64 40: <async_task::raw::RawTask<scheduler::executor::spawn_local_with_source_location::Checked<<gpui::app::App>::spawn<<gpui::app::context::Context<project::buffer_store::BufferStore>>::spawn<<project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>>::{closure#0}, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>>::{closure#0}>, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>, <scheduler::executor::ForegroundExecutor>::spawn<<gpui::app::App>::spawn<<gpui::app::context::Context<project::buffer_store::BufferStore>>::spawn<<project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>>::{closure#0}, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>>::{closure#0}>::{closure#0}, scheduler::RunnableMeta>>::run at /Users/kubkon/.cargo/git/checkouts/async-task-e468f817236eac43/b4486cd/src/raw.rs:296:17 41: <async_task::runnable::Runnable<scheduler::RunnableMeta>>::run at /Users/kubkon/.cargo/git/checkouts/async-task-e468f817236eac43/b4486cd/src/runnable.rs:788:18 42: gpui::platform::mac::dispatcher::trampoline at /Users/kubkon/dev/zed/crates/gpui/src/platform/mac/dispatcher.rs:248:14 43: <unknown> 44: <unknown> 45: <unknown> 46: <unknown> 47: <unknown> 48: <unknown> 49: <unknown> 50: <unknown> 51: <unknown> 52: <unknown> 53: <unknown> 54: <unknown> 55: <unknown> 56: <unknown> 57: <unknown> 58: <gpui::platform::mac::platform::MacPlatform as gpui::platform::Platform>::run at /Users/kubkon/dev/zed/crates/gpui/src/platform/mac/platform.rs:473:17 59: <gpui::app::Application>::run::<zed::main::{closure#9}> at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:192:18 60: zed::main at /Users/kubkon/dev/zed/crates/zed/src/main.rs:419:9 61: <fn() as core::ops::function::FnOnce<()>>::call_once at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/core/src/ops/function.rs:250:5 note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace. ``` cc @ConradIrwin @elmarco

ConradIrwin · 2026-01-23T16:57:15Z

@elmarco we ended up reverting because we're slicing a string in the middle of a utf8 byte: are you able to take a look? (I suspect it's because of the 1024 limit we added)

elmarco · 2026-01-23T19:04:54Z

@ConradIrwin Claude suggests this fix:

diff --git a/crates/rope/src/rope.rs b/crates/rope/src/rope.rs
index fba7b96aca..402f7ae104 100644
--- a/crates/rope/src/rope.rs
+++ b/crates/rope/src/rope.rs
@@ -708,6 +708,7 @@ pub struct ChunkBitmaps<'a> {

 #[derive(Clone)]
 pub struct Chunks<'a> {
+    rope: &'a Rope,
     chunks: sum_tree::Cursor<'a, 'static, Chunk, usize>,
     range: Range<usize>,
     offset: usize,
@@ -716,6 +717,11 @@ pub struct Chunks<'a> {

 impl<'a> Chunks<'a> {
     pub fn new(rope: &'a Rope, range: Range<usize>, reversed: bool) -> Self {
+        // Clip range boundaries to character boundaries to prevent panics when slicing
+        let range_start = rope.ceil_char_boundary(range.start);
+        let range_end = rope.floor_char_boundary(range.end);
+        let range = range_start..range_end.max(range_start);
+
         let mut chunks = rope.chunks.cursor(());
         let offset = if reversed {
             chunks.seek(&range.end, Bias::Left);
@@ -729,6 +735,7 @@ impl<'a> Chunks<'a> {
             chunk.assert_char_boundary::<true>(chunk_offset);
         }
         Self {
+            rope,
             chunks,
             range,
             offset,
@@ -773,8 +780,11 @@ impl<'a> Chunks<'a> {
     }

     pub fn set_range(&mut self, range: Range<usize>) {
-        self.range = range.clone();
-        self.seek(range.start);
+        // Clip range boundaries to character boundaries to prevent panics when slicing
+        let range_start = self.rope.ceil_char_boundary(range.start);
+        let range_end = self.rope.floor_char_boundary(range.end);
+        self.range = range_start..range_end.max(range_start);
+        self.seek(self.range.start);
     }

It looks reasonable. We may want to have alternatives, to return Result if the range isn't correct, but that would leave the responsability to the caller. Or have a second "safer" constructor? We could also check before peeking / slicing (but that would probably be more costly at runtime).

It would be nice to know how the panic was triggered, but we should probably add some tests for this case too.

wdyt?

Many editors such as vim and emacs support "modelines", a comment at the beginning of the file that allows the file type to be explicitly specified along with per-file specific settings - The amount of configurations, style and settings mapping cannot be handled in one go, so this opens up a lot of potential improvements. - I left out the possiblity to have "zed" specific modelines for now, but this could be potentially interesting. - Mapping the mode or filetype to zed language names isn't obvious either. We may want to make it configurable. This is my first contribution to zed, be kind. I struggled a bit to find the right place to add those settings. I use a similar approach as done with editorconfig (merge_with_editorconfig). There might be better ways. Closes zed-industries#4762 Release Notes: - Add basic emacs/vim modeline support. Supersedes zed-industries#41899, changes: - limit reading to the first and last 1kb - add documentation - more variables handled - add Arc around ModelineSettings to avoid extra cloning - changed the way mode -> language mapping is done, thanks to `modeline_aliases` language config - drop vim ex: support - made "Local Variables:" handling a separate commit, so we can drop it easily - various code style improvements --------- Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Co-authored-by: Claude <noreply@anthropic.com> Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>

ConradIrwin · 2026-01-27T03:29:45Z

We should fix this in the modeline code, not in the rope code. Time permitting I can take a pass later in the week. In general in rust it is unsafe to ever break a string or a text or a rope at an index that is not a utf-8 boundary, so we shouldn't silently adjust requested ranges for callers: they're supposed to do the right thing.

elmarco · 2026-01-27T13:30:55Z

@ConradIrwin that makes the rope functions panic easily. There could be a new_checked_range() version? or perhaps a make_valid_range() that returns a valid range for the caller?

ConradIrwin · 2026-01-27T22:24:40Z

Maybe? Does the rust string API have something similar we can copy. (It also has the ridiculous problem that calling methods on it can panic; but as we're written in rust it's best to fit into the ecosystem).

Many editors such as vim and emacs support "modelines", a comment at the beginning of the file that allows the file type to be explicitly specified along with per-file specific settings - The amount of configurations, style and settings mapping cannot be handled in one go, so this opens up a lot of potential improvements. - I left out the possiblity to have "zed" specific modelines for now, but this could be potentially interesting. - Mapping the mode or filetype to zed language names isn't obvious either. We may want to make it configurable. This is my first contribution to zed, be kind. I struggled a bit to find the right place to add those settings. I use a similar approach as done with editorconfig (merge_with_editorconfig). There might be better ways. Closes zed-industries#4762 Release Notes: - Add basic emacs/vim modeline support. Supersedes zed-industries#41899, changes: - limit reading to the first and last 1kb - add documentation - more variables handled - add Arc around ModelineSettings to avoid extra cloning - changed the way mode -> language mapping is done, thanks to `modeline_aliases` language config - drop vim ex: support - made "Local Variables:" handling a separate commit, so we can drop it easily - various code style improvements --------- Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Co-authored-by: Claude <noreply@anthropic.com> Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>

elmarco · 2026-02-11T13:07:09Z

@ConradIrwin did you have a chance to look at the last update? should I open a new PR?

ConradIrwin · 2026-02-12T04:31:59Z

@elmarco Which update? Sorry I must have missed it

elmarco · 2026-02-12T09:25:20Z

@ConradIrwin main...elmarco:zed:modeline
or the fix itself: 198f486

let me know if I should rebase and make a new PR.

ConradIrwin · 2026-02-12T15:40:51Z

Thanks. Happy to merge a new PR.

Instead of adding chunks_in_range_safe let's just call clip_offset(end, Bias::Left) at the caller.

Suggested by Conrad: zed-industries#44210 (comment)

@ConradIrwin

Reverts zed-industries/zed#44210 I am forced to revert this PR as it completely breaks release builds with the following panic: ``` thread 'main' (2648653) panicked at crates/rope/src/rope.rs:893:25: byte index 73 is not a char boundary; it is inside 'স' (bytes 71..74) of `কৰক</translation> <translation id="9216898458513705996">টেবসমূহ এই ডিভাইচত খোলা ` stack backtrace: 2026-01-23T15:37:48+01:00 INFO [node_runtime] using Zed managed Node.js at /Users/kubkon/Library/Application Support/Zed/node/node-v24.11.0-darwin-arm64 since system Node.js wasn't found on PATH: cannot find binary path 0: __rustc::rust_begin_unwind at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/std/src/panicking.rs:698:5 1: core::panicking::panic_fmt at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/core/src/panicking.rs:80:14 2: core::str::slice_error_fail_rt 3: core::str::slice_error_fail at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/core/src/str/mod.rs:69:5 4: core::str::traits::<impl core::slice::index::SliceIndex<str> for core::ops::range::Range<usize>>::index at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/core/src/str/traits.rs:248:21 5: <str as core::ops::index::Index<core::ops::range::Range<usize>>>::index at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/core/src/str/traits.rs:63:15 6: <rope::Chunks>::peek at /Users/kubkon/dev/zed/crates/rope/src/rope.rs:893:25 7: <rope::Lines>::next at /Users/kubkon/dev/zed/crates/rope/src/rope.rs:1111:45 8: <project::lsp_store::LspStore>::parse_modeline at /Users/kubkon/dev/zed/crates/project/src/lsp_store.rs:4570:43 9: <project::lsp_store::LspStore>::on_buffer_added at /Users/kubkon/dev/zed/crates/project/src/lsp_store.rs:4301:14 10: <project::lsp_store::LspStore>::on_buffer_store_event at /Users/kubkon/dev/zed/crates/project/src/lsp_store.rs:4166:22 11: <<project::lsp_store::LspStore>::on_buffer_store_event as core::ops::function::FnMut<(&mut project::lsp_store::LspStore, gpui::app::entity_map::Entity<project::buffer_store::BufferStore>, &project::buffer_store::BufferStoreEvent, &mut gpui::app::context::Context<project::lsp_store::LspStore>)>>::call_mut at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/core/src/ops/function.rs:166:5 12: <gpui::app::context::Context<project::lsp_store::LspStore>>::subscribe::<project::buffer_store::BufferStore, project::buffer_store::BufferStoreEvent, <project::lsp_store::LspStore>::on_buffer_store_event>::{closure#0}::{closure#0} at /Users/kubkon/dev/zed/crates/gpui/src/app/context.rs:111:44 13: <gpui::app::App as gpui::AppContext>::update_entity::<project::lsp_store::LspStore, (), <gpui::app::context::Context<project::lsp_store::LspStore>>::subscribe<project::buffer_store::BufferStore, project::buffer_store::BufferStoreEvent, <project::lsp_store::LspStore>::on_buffer_store_event>::{closure#0}::{closure#0}>::{closure#0} at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:2281:26 14: <gpui::app::App>::update::<(), <gpui::app::App as gpui::AppContext>::update_entity<project::lsp_store::LspStore, (), <gpui::app::context::Context<project::lsp_store::LspStore>>::subscribe<project::buffer_store::BufferStore, project::buffer_store::BufferStoreEvent, <project::lsp_store::LspStore>::on_buffer_store_event>::{closure#0}::{closure#0}>::{closure#0}> at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:818:22 15: <gpui::app::App as gpui::AppContext>::update_entity::<project::lsp_store::LspStore, (), <gpui::app::context::Context<project::lsp_store::LspStore>>::subscribe<project::buffer_store::BufferStore, project::buffer_store::BufferStoreEvent, <project::lsp_store::LspStore>::on_buffer_store_event>::{closure#0}::{closure#0}> at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:2279:14 16: <gpui::app::entity_map::Entity<project::lsp_store::LspStore>>::update::<(), gpui::app::App, <gpui::app::context::Context<project::lsp_store::LspStore>>::subscribe<project::buffer_store::BufferStore, project::buffer_store::BufferStoreEvent, <project::lsp_store::LspStore>::on_buffer_store_event>::{closure#0}::{closure#0}> at /Users/kubkon/dev/zed/crates/gpui/src/app/entity_map.rs:445:12 17: <gpui::app::context::Context<project::lsp_store::LspStore>>::subscribe::<project::buffer_store::BufferStore, project::buffer_store::BufferStoreEvent, <project::lsp_store::LspStore>::on_buffer_store_event>::{closure#0} at /Users/kubkon/dev/zed/crates/gpui/src/app/context.rs:111:22 18: <gpui::app::App>::subscribe_internal::<project::buffer_store::BufferStore, project::buffer_store::BufferStoreEvent, <gpui::app::context::Context<project::lsp_store::LspStore>>::subscribe<project::buffer_store::BufferStore, project::buffer_store::BufferStoreEvent, <project::lsp_store::LspStore>::on_buffer_store_event>::{closure#0}>::{closure#0} at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:964:25 19: <alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>> as core::ops::function::FnMut<(&dyn core::any::Any, &mut gpui::app::App)>>::call_mut at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/alloc/src/boxed.rs:2012:9 20: <gpui::app::App>::apply_emit_effect::{closure#0} at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:1407:21 21: <gpui::subscription::SubscriberSet<gpui::app::entity_map::EntityId, (core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>::retain::<<gpui::app::App>::apply_emit_effect::{closure#0}>::{closure#1} at /Users/kubkon/dev/zed/crates/gpui/src/subscription.rs:132:17 22: <alloc::collections::btree::map::BTreeMap<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>>::retain::<<gpui::subscription::SubscriberSet<gpui::app::entity_map::EntityId, (core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>::retain<<gpui::app::App>::apply_emit_effect::{closure#0}>::{closure#1}>::{closure#0} at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/alloc/src/collections/btree/map.rs:1177:37 23: <alloc::collections::btree::map::ExtractIfInner<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>, core::ops::range::RangeFull>>::next::<<alloc::collections::btree::map::BTreeMap<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>>::retain<<gpui::subscription::SubscriberSet<gpui::app::entity_map::EntityId, (core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>::retain<<gpui::app::App>::apply_emit_effect::{closure#0}>::{closure#1}>::{closure#0}, alloc::alloc::Global> at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/alloc/src/collections/btree/map.rs:2036:16 24: <alloc::collections::btree::map::ExtractIf<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>, core::ops::range::RangeFull, <alloc::collections::btree::map::BTreeMap<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>>::retain<<gpui::subscription::SubscriberSet<gpui::app::entity_map::EntityId, (core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>::retain<<gpui::app::App>::apply_emit_effect::{closure#0}>::{closure#1}>::{closure#0}> as core::iter::traits::iterator::Iterator>::next at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/alloc/src/collections/btree/map.rs:2002:20 25: <alloc::collections::btree::map::ExtractIf<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>, core::ops::range::RangeFull, <alloc::collections::btree::map::BTreeMap<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>>::retain<<gpui::subscription::SubscriberSet<gpui::app::entity_map::EntityId, (core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>::retain<<gpui::app::App>::apply_emit_effect::{closure#0}>::{closure#1}>::{closure#0}> as core::iter::traits::iterator::Iterator>::fold::<(), core::iter::traits::iterator::Iterator::for_each::call<(usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>), core::mem::drop<(usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>)>>::{closure#0}> at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/core/src/iter/traits/iterator.rs:2602:34 26: <alloc::collections::btree::map::ExtractIf<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>, core::ops::range::RangeFull, <alloc::collections::btree::map::BTreeMap<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>>::retain<<gpui::subscription::SubscriberSet<gpui::app::entity_map::EntityId, (core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>::retain<<gpui::app::App>::apply_emit_effect::{closure#0}>::{closure#1}>::{closure#0}> as core::iter::traits::iterator::Iterator>::for_each::<core::mem::drop<(usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>)>> at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/core/src/iter/traits/iterator.rs:828:14 27: <alloc::collections::btree::map::BTreeMap<usize, gpui::subscription::Subscriber<(core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>>::retain::<<gpui::subscription::SubscriberSet<gpui::app::entity_map::EntityId, (core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>::retain<<gpui::app::App>::apply_emit_effect::{closure#0}>::{closure#1}> at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/alloc/src/collections/btree/map.rs:1177:46 28: <gpui::subscription::SubscriberSet<gpui::app::entity_map::EntityId, (core::any::TypeId, alloc::boxed::Box<dyn for<'a, 'b> core::ops::function::FnMut<(&'a dyn core::any::Any, &'b mut gpui::app::App), Output = bool>>)>>::retain::<<gpui::app::App>::apply_emit_effect::{closure#0}> at /Users/kubkon/dev/zed/crates/gpui/src/subscription.rs:130:21 29: <gpui::app::App>::apply_emit_effect at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:1405:14 30: <gpui::app::App>::flush_effects at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:1308:31 31: <gpui::app::App>::finish_update at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:830:18 32: <gpui::app::App>::update::<core::result::Result<(), anyhow::Error>, <gpui::app::App as gpui::AppContext>::update_entity<project::buffer_store::BufferStore, core::result::Result<(), anyhow::Error>, <project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}::{closure#0}::{closure#3}>::{closure#0}> at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:819:14 33: <gpui::app::App as gpui::AppContext>::update_entity::<project::buffer_store::BufferStore, core::result::Result<(), anyhow::Error>, <project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}::{closure#0}::{closure#3}> at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:2279:14 34: <gpui::app::async_context::AsyncApp as gpui::AppContext>::update_entity::<project::buffer_store::BufferStore, core::result::Result<(), anyhow::Error>, <project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}::{closure#0}::{closure#3}> at /Users/kubkon/dev/zed/crates/gpui/src/app/async_context.rs:65:13 35: <gpui::app::entity_map::WeakEntity<project::buffer_store::BufferStore>>::update::<gpui::app::async_context::AsyncApp, core::result::Result<(), anyhow::Error>, <project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}::{closure#0}::{closure#3}> at /Users/kubkon/dev/zed/crates/gpui/src/app/entity_map.rs:750:15 36: <project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}::{closure#0}::<i32> at /Users/kubkon/dev/zed/crates/project/src/buffer_store.rs:683:18 37: <gpui::app::context::Context<project::buffer_store::BufferStore>>::spawn::<<project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>>::{closure#0}::{closure#0}::<i32> at /Users/kubkon/dev/zed/crates/gpui/src/app/context.rs:244:52 38: <gpui::app::App>::spawn::<<gpui::app::context::Context<project::buffer_store::BufferStore>>::spawn<<project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>>::{closure#0}, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>>::{closure#0} at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:1532:44 39: <scheduler::executor::spawn_local_with_source_location::Checked<<gpui::app::App>::spawn<<gpui::app::context::Context<project::buffer_store::BufferStore>>::spawn<<project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>>::{closure#0}, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>>::{closure#0}> as core::future::future::Future>::poll at /Users/kubkon/dev/zed/crates/scheduler/src/executor.rs:393:64 40: <async_task::raw::RawTask<scheduler::executor::spawn_local_with_source_location::Checked<<gpui::app::App>::spawn<<gpui::app::context::Context<project::buffer_store::BufferStore>>::spawn<<project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>>::{closure#0}, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>>::{closure#0}>, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>, <scheduler::executor::ForegroundExecutor>::spawn<<gpui::app::App>::spawn<<gpui::app::context::Context<project::buffer_store::BufferStore>>::spawn<<project::buffer_store::LocalBufferStore>::open_buffer::{closure#1}, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>>::{closure#0}, core::result::Result<gpui::app::entity_map::Entity<language::buffer::Buffer>, anyhow::Error>>::{closure#0}>::{closure#0}, scheduler::RunnableMeta>>::run at /Users/kubkon/.cargo/git/checkouts/async-task-e468f817236eac43/b4486cd/src/raw.rs:296:17 41: <async_task::runnable::Runnable<scheduler::RunnableMeta>>::run at /Users/kubkon/.cargo/git/checkouts/async-task-e468f817236eac43/b4486cd/src/runnable.rs:788:18 42: gpui::platform::mac::dispatcher::trampoline at /Users/kubkon/dev/zed/crates/gpui/src/platform/mac/dispatcher.rs:248:14 43: <unknown> 44: <unknown> 45: <unknown> 46: <unknown> 47: <unknown> 48: <unknown> 49: <unknown> 50: <unknown> 51: <unknown> 52: <unknown> 53: <unknown> 54: <unknown> 55: <unknown> 56: <unknown> 57: <unknown> 58: <gpui::platform::mac::platform::MacPlatform as gpui::platform::Platform>::run at /Users/kubkon/dev/zed/crates/gpui/src/platform/mac/platform.rs:473:17 59: <gpui::app::Application>::run::<zed::main::{closure#9}> at /Users/kubkon/dev/zed/crates/gpui/src/app.rs:192:18 60: zed::main at /Users/kubkon/dev/zed/crates/zed/src/main.rs:419:9 61: <fn() as core::ops::function::FnOnce<()>>::call_once at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/core/src/ops/function.rs:250:5 note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace. ``` cc @ConradIrwin @elmarco

Suggested by Conrad: zed-industries#44210 (comment)

cla-bot bot added the cla-signed The user has signed the Contributor License Agreement label Dec 5, 2025

elmarco force-pushed the modeline branch 3 times, most recently from 6e99a43 to dc77c46 Compare December 6, 2025 06:18

ConradIrwin self-assigned this Dec 10, 2025

elmarco force-pushed the modeline branch 2 times, most recently from 67a9c5f to 9b213a0 Compare December 11, 2025 21:04

zelenenka added this to Quality Week – December 2025 Dec 12, 2025

github-project-automation bot moved this to Community PRs in Quality Week – December 2025 Dec 12, 2025

ConradIrwin moved this from Community PRs to In progress in Quality Week – December 2025 Dec 15, 2025

elmarco force-pushed the modeline branch from 9b213a0 to a1c4bf6 Compare December 23, 2025 19:37

elmarco and others added 11 commits January 8, 2026 14:14

language: use settings::MergeFrom for editorconfig

880c6be

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

docs: add Modelines documentation

baf04f0

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

language: Add "modeline" parsing unit

660aa3f

Co-authored-by: Claude <noreply@anthropic.com> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

language: Add emacs "Local Variables:" parsing support

42f9695

Co-authored-by: Claude <noreply@anthropic.com> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

settings: Add "modeline_lines"

c897316

This will allow to configure vim/emacs modeline support. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

language: add LanguageRegistry::available_language_for_modeline_name()

86715ab

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

languages: add extra modeline aliases

3fdb3af

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

language: add Buffer::modeline

53dab8f

Add an optional ModelineSettings to Buffer and BufferSnapshot. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

project: load modeline

b7a1350

When the buffer is added on reloaded, parse the modelines and update the detected language. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

language: add modeline for language_settings()

b7d2952

Associated buffer's modeline is now merged. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

elmarco force-pushed the modeline branch from a1c4bf6 to b7d2952 Compare January 8, 2026 11:46

ConradIrwin added 4 commits January 22, 2026 19:59

Use buffer_snapshot_at not file/line to consider modeline

20560c4

Remove the file accessors for settings

3cecde0

Now we need to take modeline into account they are not viable.

Remove erroneous uses of .language

055baca

Buffers have their own language, so it's almost always an error to specify the buffer and the language (unless you're in a situation where you already did .language_at() or equivalent).

Move from builder methods to accessors

96699e1

The builder methods were not composible (i.e. you had to be careful to call .language() after .buffer()), so it seems safer to not do that.

ConradIrwin added 3 commits January 23, 2026 00:11

silence log

8d6d510

Merge branch 'main' into modeline

af83478

Fix merge conflicts

bf0ae28

ConradIrwin enabled auto-merge (squash) January 23, 2026 07:49

ConradIrwin merged commit 4186e57 into zed-industries:main Jan 23, 2026
27 checks passed

github-project-automation bot moved this from In progress to Done in Quality Week – December 2025 Jan 23, 2026

kubkon added a commit that referenced this pull request Jan 23, 2026

Revert " Add vim/emacs modeline support (#44210)"

e8a0202

This reverts commit 4186e57.

kubkon mentioned this pull request Jan 23, 2026

Revert " Add vim/emacs modeline support " #47479

Merged

elmarco added a commit to elmarco/zed that referenced this pull request Feb 16, 2026

Use clip_offset(end, Bias::Left)

d1c84c7

Suggested by Conrad: zed-industries#44210 (comment)

elmarco added a commit to elmarco/zed that referenced this pull request Mar 19, 2026

Use clip_offset(end, Bias::Left)

770d036

Suggested by Conrad: zed-industries#44210 (comment)

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