diff options
Diffstat (limited to 'docs/dev')
-rw-r--r-- | docs/dev/README.md | 111 | ||||
-rw-r--r-- | docs/dev/architecture.md | 4 | ||||
-rw-r--r-- | docs/dev/debugging.md | 14 | ||||
-rw-r--r-- | docs/dev/guide.md | 8 | ||||
-rw-r--r-- | docs/dev/lsp-extensions.md | 445 | ||||
-rw-r--r-- | docs/dev/lsp-features.md | 72 | ||||
-rw-r--r-- | docs/dev/syntax.md | 42 |
7 files changed, 586 insertions, 110 deletions
diff --git a/docs/dev/README.md b/docs/dev/README.md index f230dc1db..1de5a2aab 100644 --- a/docs/dev/README.md +++ b/docs/dev/README.md | |||
@@ -30,7 +30,7 @@ https://rust-lang.zulipchat.com/#narrow/stream/185405-t-compiler.2Fwg-rls-2.2E0 | |||
30 | 30 | ||
31 | * [good-first-issue](https://github.com/rust-analyzer/rust-analyzer/labels/good%20first%20issue) | 31 | * [good-first-issue](https://github.com/rust-analyzer/rust-analyzer/labels/good%20first%20issue) |
32 | are good issues to get into the project. | 32 | are good issues to get into the project. |
33 | * [E-mentor](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-mentor) | 33 | * [E-has-instructions](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-has-instructions) |
34 | issues have links to the code in question and tests. | 34 | issues have links to the code in question and tests. |
35 | * [E-easy](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-easy), | 35 | * [E-easy](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-easy), |
36 | [E-medium](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-medium), | 36 | [E-medium](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-medium), |
@@ -74,7 +74,7 @@ relevant test and execute it (VS Code includes an action for running a single | |||
74 | test). | 74 | test). |
75 | 75 | ||
76 | However, launching a VS Code instance with locally build language server is | 76 | However, launching a VS Code instance with locally build language server is |
77 | possible. There's **"Run Extension (Dev Server)"** launch configuration for this. | 77 | possible. There's **"Run Extension (Debug Build)"** launch configuration for this. |
78 | 78 | ||
79 | In general, I use one of the following workflows for fixing bugs and | 79 | In general, I use one of the following workflows for fixing bugs and |
80 | implementing features. | 80 | implementing features. |
@@ -86,7 +86,7 @@ then just do printf-driven development/debugging. As a sanity check after I'm | |||
86 | done, I use `cargo xtask install --server` and **Reload Window** action in VS | 86 | done, I use `cargo xtask install --server` and **Reload Window** action in VS |
87 | Code to sanity check that the thing works as I expect. | 87 | Code to sanity check that the thing works as I expect. |
88 | 88 | ||
89 | If the problem concerns only the VS Code extension, I use **Run Extension** | 89 | If the problem concerns only the VS Code extension, I use **Run Installed Extension** |
90 | launch configuration from `launch.json`. Notably, this uses the usual | 90 | launch configuration from `launch.json`. Notably, this uses the usual |
91 | `rust-analyzer` binary from `PATH`. For this it is important to have the following | 91 | `rust-analyzer` binary from `PATH`. For this it is important to have the following |
92 | in `setting.json` file: | 92 | in `setting.json` file: |
@@ -117,6 +117,109 @@ Additionally, I use `cargo run --release -p rust-analyzer -- analysis-stats | |||
117 | path/to/some/rust/crate` to run a batch analysis. This is primarily useful for | 117 | path/to/some/rust/crate` to run a batch analysis. This is primarily useful for |
118 | performance optimizations, or for bug minimization. | 118 | performance optimizations, or for bug minimization. |
119 | 119 | ||
120 | # Code Style & Review Process | ||
121 | |||
122 | Our approach to "clean code" is two fold: | ||
123 | |||
124 | * We generally don't block PRs on style changes. | ||
125 | * At the same time, all code in rust-analyzer is constantly refactored. | ||
126 | |||
127 | It is explicitly OK for reviewer to flag only some nits in the PR, and than send a follow up cleanup PR for things which are easier to explain by example, cc-ing the original author. | ||
128 | Sending small cleanup PRs (like rename a single local variable) is encouraged. | ||
129 | |||
130 | ## Scale of Changes | ||
131 | |||
132 | Everyone knows that it's better to send small & focused pull requests. | ||
133 | The problem is, sometimes you *have* to, eg, rewrite the whole compiler, and that just doesn't fit into a set of isolated PRs. | ||
134 | |||
135 | The main thing too keep an eye on is the boundaries between various components. | ||
136 | There are three kinds of changes: | ||
137 | |||
138 | 1. Internals of a single component are changed. | ||
139 | Specifically, you don't change any `pub` items. | ||
140 | A good example here would be an addition of a new assist. | ||
141 | |||
142 | 2. API of a component is expanded. | ||
143 | Specifically, you add a new `pub` function which wasn't there before. | ||
144 | A good example here would be expansion of assist API, for example, to implement lazy assists or assists groups. | ||
145 | |||
146 | 3. A new dependency between components is introduced. | ||
147 | Specifically, you add a `pub use` reexport from another crate or you add a new line to `[dependencies]` section of `Cargo.toml`. | ||
148 | A good example here would be adding reference search capability to the assists crates. | ||
149 | |||
150 | For the first group, the change is generally merged as long as: | ||
151 | |||
152 | * it works for the happy case, | ||
153 | * it has tests, | ||
154 | * it doesn't panic for unhappy case. | ||
155 | |||
156 | For the second group, the change would be subjected to quite a bit of scrutiny and iteration. | ||
157 | The new API needs to be right (or at least easy to change later). | ||
158 | The actual implementation doesn't matter that much. | ||
159 | It's very important to minimize the amount of changed lines of code for changes of the second kind. | ||
160 | Often, you start doing change of the first kind, only to realise that you need to elevate to a change of the second kind. | ||
161 | In this case, we'll probably ask you to split API changes into a separate PR. | ||
162 | |||
163 | Changes of the third group should be pretty rare, so we don't specify any specific process for them. | ||
164 | That said, adding an innocent-looking `pub use` is a very simple way to break encapsulation, keep an eye on it! | ||
165 | |||
166 | Note: if you enjoyed this abstract hand-waving about boundaries, you might appreciate | ||
167 | https://www.tedinski.com/2018/02/06/system-boundaries.html | ||
168 | |||
169 | ## Order of Imports | ||
170 | |||
171 | We separate import groups with blank lines | ||
172 | |||
173 | ``` | ||
174 | mod x; | ||
175 | mod y; | ||
176 | |||
177 | use std::{ ... } | ||
178 | |||
179 | use crate_foo::{ ... } | ||
180 | use crate_bar::{ ... } | ||
181 | |||
182 | use crate::{} | ||
183 | |||
184 | use super::{} // but prefer `use crate::` | ||
185 | ``` | ||
186 | |||
187 | ## Order of Items | ||
188 | |||
189 | Optimize for the reader who sees the file for the first time, and wants to get the general idea about what's going on. | ||
190 | People read things from top to bottom, so place most important things first. | ||
191 | |||
192 | Specifically, if all items except one are private, always put the non-private item on top. | ||
193 | |||
194 | Put `struct`s and `enum`s first, functions and impls last. | ||
195 | |||
196 | Do | ||
197 | |||
198 | ``` | ||
199 | // Good | ||
200 | struct Foo { | ||
201 | bars: Vec<Bar> | ||
202 | } | ||
203 | |||
204 | struct Bar; | ||
205 | ``` | ||
206 | |||
207 | rather than | ||
208 | |||
209 | ``` | ||
210 | // Not as good | ||
211 | struct Bar; | ||
212 | |||
213 | struct Foo { | ||
214 | bars: Vec<Bar> | ||
215 | } | ||
216 | ``` | ||
217 | |||
218 | ## Documentation | ||
219 | |||
220 | For `.md` and `.adoc` files, prefer a sentence-per-line format, don't wrap lines. | ||
221 | If the line is too long, you want to split the sentence in two :-) | ||
222 | |||
120 | # Logging | 223 | # Logging |
121 | 224 | ||
122 | Logging is done by both rust-analyzer and VS Code, so it might be tricky to | 225 | Logging is done by both rust-analyzer and VS Code, so it might be tricky to |
@@ -134,7 +237,7 @@ To log all communication between the server and the client, there are two choice | |||
134 | 237 | ||
135 | * you can log on the server side, by running something like | 238 | * you can log on the server side, by running something like |
136 | ``` | 239 | ``` |
137 | env RUST_LOG=gen_lsp_server=trace code . | 240 | env RA_LOG=gen_lsp_server=trace code . |
138 | ``` | 241 | ``` |
139 | 242 | ||
140 | * you can log on the client side, by enabling `"rust-analyzer.trace.server": | 243 | * you can log on the client side, by enabling `"rust-analyzer.trace.server": |
diff --git a/docs/dev/architecture.md b/docs/dev/architecture.md index 3a337c574..cee916c09 100644 --- a/docs/dev/architecture.md +++ b/docs/dev/architecture.md | |||
@@ -46,7 +46,7 @@ can be quickly updated for small modifications. | |||
46 | 46 | ||
47 | Some of the components of this repository are generated through automatic | 47 | Some of the components of this repository are generated through automatic |
48 | processes. `cargo xtask codegen` runs all generation tasks. Generated code is | 48 | processes. `cargo xtask codegen` runs all generation tasks. Generated code is |
49 | commited to the git repository. | 49 | committed to the git repository. |
50 | 50 | ||
51 | In particular, `cargo xtask codegen` generates: | 51 | In particular, `cargo xtask codegen` generates: |
52 | 52 | ||
@@ -114,7 +114,7 @@ is responsible for guessing a HIR for a particular source position. | |||
114 | Underneath, HIR works on top of salsa, using a `HirDatabase` trait. | 114 | Underneath, HIR works on top of salsa, using a `HirDatabase` trait. |
115 | 115 | ||
116 | `ra_hir_xxx` crates have a strong ECS flavor, in that they work with raw ids and | 116 | `ra_hir_xxx` crates have a strong ECS flavor, in that they work with raw ids and |
117 | directly query the databse. | 117 | directly query the database. |
118 | 118 | ||
119 | The top-level `ra_hir` façade crate wraps ids into a more OO-flavored API. | 119 | The top-level `ra_hir` façade crate wraps ids into a more OO-flavored API. |
120 | 120 | ||
diff --git a/docs/dev/debugging.md b/docs/dev/debugging.md index bece6a572..59a83f7d7 100644 --- a/docs/dev/debugging.md +++ b/docs/dev/debugging.md | |||
@@ -22,11 +22,11 @@ where **only** the `rust-analyzer` extension being debugged is enabled. | |||
22 | 22 | ||
23 | ## Debug TypeScript VSCode extension | 23 | ## Debug TypeScript VSCode extension |
24 | 24 | ||
25 | - `Run Extension` - runs the extension with the globally installed `rust-analyzer` binary. | 25 | - `Run Installed Extension` - runs the extension with the globally installed `rust-analyzer` binary. |
26 | - `Run Extension (Dev Server)` - runs extension with the locally built LSP server (`target/debug/rust-analyzer`). | 26 | - `Run Extension (Debug Build)` - runs extension with the locally built LSP server (`target/debug/rust-analyzer`). |
27 | 27 | ||
28 | TypeScript debugging is configured to watch your source edits and recompile. | 28 | TypeScript debugging is configured to watch your source edits and recompile. |
29 | To apply changes to an already running debug process press <kbd>Ctrl+Shift+P</kbd> and run the following command in your `[Extension Development Host]` | 29 | To apply changes to an already running debug process, press <kbd>Ctrl+Shift+P</kbd> and run the following command in your `[Extension Development Host]` |
30 | 30 | ||
31 | ``` | 31 | ``` |
32 | > Developer: Reload Window | 32 | > Developer: Reload Window |
@@ -47,7 +47,7 @@ To apply changes to an already running debug process press <kbd>Ctrl+Shift+P</kb | |||
47 | debug = 2 | 47 | debug = 2 |
48 | ``` | 48 | ``` |
49 | 49 | ||
50 | - Select `Run Extension (Dev Server)` to run your locally built `target/debug/rust-analyzer`. | 50 | - Select `Run Extension (Debug Build)` to run your locally built `target/debug/rust-analyzer`. |
51 | 51 | ||
52 | - In the original VSCode window once again select the `Attach To Server` debug configuration. | 52 | - In the original VSCode window once again select the `Attach To Server` debug configuration. |
53 | 53 | ||
@@ -76,11 +76,11 @@ Make sure you open a rust file in the `[Extension Development Host]` and try aga | |||
76 | 76 | ||
77 | Make sure you have run `echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope`. | 77 | Make sure you have run `echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope`. |
78 | 78 | ||
79 | By default this should reset back to 1 everytime you log in. | 79 | By default this should reset back to 1 every time you log in. |
80 | 80 | ||
81 | ### Breakpoints are never being hit | 81 | ### Breakpoints are never being hit |
82 | 82 | ||
83 | Check your version of `lldb` if it's version 6 and lower use the `classic` adapter type. | 83 | Check your version of `lldb`. If it's version 6 and lower, use the `classic` adapter type. |
84 | It's `lldb.adapterType` in settings file. | 84 | It's `lldb.adapterType` in settings file. |
85 | 85 | ||
86 | If you're running `lldb` version 7 change the lldb adapter type to `bundled` or `native`. | 86 | If you're running `lldb` version 7, change the lldb adapter type to `bundled` or `native`. |
diff --git a/docs/dev/guide.md b/docs/dev/guide.md index abbe4c154..c3252f1f6 100644 --- a/docs/dev/guide.md +++ b/docs/dev/guide.md | |||
@@ -26,7 +26,7 @@ properties hold: | |||
26 | 26 | ||
27 | ## IDE API | 27 | ## IDE API |
28 | 28 | ||
29 | To see the bigger picture of how the IDE features works, let's take a look at the [`AnalysisHost`] and | 29 | To see the bigger picture of how the IDE features work, let's take a look at the [`AnalysisHost`] and |
30 | [`Analysis`] pair of types. `AnalysisHost` has three methods: | 30 | [`Analysis`] pair of types. `AnalysisHost` has three methods: |
31 | 31 | ||
32 | * `default()` for creating an empty analysis instance | 32 | * `default()` for creating an empty analysis instance |
@@ -131,7 +131,7 @@ mapping between `SourceRoot` IDs (which are assigned by the client) and actual | |||
131 | analyzer. | 131 | analyzer. |
132 | 132 | ||
133 | Note that `mod`, `#[path]` and `include!()` can only reference files from the | 133 | Note that `mod`, `#[path]` and `include!()` can only reference files from the |
134 | same source root. It is of course is possible to explicitly add extra files to | 134 | same source root. It is of course possible to explicitly add extra files to |
135 | the source root, even `/dev/random`. | 135 | the source root, even `/dev/random`. |
136 | 136 | ||
137 | ## Language Server Protocol | 137 | ## Language Server Protocol |
@@ -192,7 +192,7 @@ task will be canceled as soon as the main loop calls `apply_change` on the | |||
192 | [`schedule`]: https://github.com/rust-analyzer/rust-analyzer/blob/guide-2019-01/crates/ra_lsp_server/src/main_loop.rs#L426-L455 | 192 | [`schedule`]: https://github.com/rust-analyzer/rust-analyzer/blob/guide-2019-01/crates/ra_lsp_server/src/main_loop.rs#L426-L455 |
193 | [The task]: https://github.com/rust-analyzer/rust-analyzer/blob/guide-2019-01/crates/ra_lsp_server/src/main_loop/handlers.rs#L205-L223 | 193 | [The task]: https://github.com/rust-analyzer/rust-analyzer/blob/guide-2019-01/crates/ra_lsp_server/src/main_loop/handlers.rs#L205-L223 |
194 | 194 | ||
195 | This concludes the overview of the analyzer's programing *interface*. Next, lets | 195 | This concludes the overview of the analyzer's programing *interface*. Next, let's |
196 | dig into the implementation! | 196 | dig into the implementation! |
197 | 197 | ||
198 | ## Salsa | 198 | ## Salsa |
@@ -480,7 +480,7 @@ throughout the analyzer: | |||
480 | ## Source Map pattern | 480 | ## Source Map pattern |
481 | 481 | ||
482 | Due to an obscure edge case in completion, IDE needs to know the syntax node of | 482 | Due to an obscure edge case in completion, IDE needs to know the syntax node of |
483 | an use statement which imported the given completion candidate. We can't just | 483 | a use statement which imported the given completion candidate. We can't just |
484 | store the syntax node as a part of name resolution: this will break | 484 | store the syntax node as a part of name resolution: this will break |
485 | incrementality, due to the fact that syntax changes after every file | 485 | incrementality, due to the fact that syntax changes after every file |
486 | modification. | 486 | modification. |
diff --git a/docs/dev/lsp-extensions.md b/docs/dev/lsp-extensions.md new file mode 100644 index 000000000..647cf6107 --- /dev/null +++ b/docs/dev/lsp-extensions.md | |||
@@ -0,0 +1,445 @@ | |||
1 | # LSP Extensions | ||
2 | |||
3 | This document describes LSP extensions used by rust-analyzer. | ||
4 | It's a best effort document, when in doubt, consult the source (and send a PR with clarification ;-) ). | ||
5 | We aim to upstream all non Rust-specific extensions to the protocol, but this is not a top priority. | ||
6 | All capabilities are enabled via `experimental` field of `ClientCapabilities` or `ServerCapabilities`. | ||
7 | Requests which we hope to upstream live under `experimental/` namespace. | ||
8 | Requests, which are likely to always remain specific to `rust-analyzer` are under `rust-analyzer/` namespace. | ||
9 | |||
10 | If you want to be notified about the changes to this document, subscribe to [#4604](https://github.com/rust-analyzer/rust-analyzer/issues/4604). | ||
11 | |||
12 | ## `initializationOptions` | ||
13 | |||
14 | As `initializationOptions`, `rust-analyzer` expects `"rust-analyzer"` section of the configuration. | ||
15 | That is, `rust-analyzer` usually sends `"workspace/configuration"` request with `{ "items": ["rust-analyzer"] }` payload. | ||
16 | `initializationOptions` should contain the same data that would be in the first item of the result. | ||
17 | It's OK to not send anything, then all the settings would take their default values. | ||
18 | However, some settings can not be changed after startup at the moment. | ||
19 | |||
20 | ## Snippet `TextEdit` | ||
21 | |||
22 | **Issue:** https://github.com/microsoft/language-server-protocol/issues/724 | ||
23 | |||
24 | **Client Capability:** `{ "snippetTextEdit": boolean }` | ||
25 | |||
26 | If this capability is set, `WorkspaceEdit`s returned from `codeAction` requests might contain `SnippetTextEdit`s instead of usual `TextEdit`s: | ||
27 | |||
28 | ```typescript | ||
29 | interface SnippetTextEdit extends TextEdit { | ||
30 | insertTextFormat?: InsertTextFormat; | ||
31 | } | ||
32 | ``` | ||
33 | |||
34 | ```typescript | ||
35 | export interface TextDocumentEdit { | ||
36 | textDocument: VersionedTextDocumentIdentifier; | ||
37 | edits: (TextEdit | SnippetTextEdit)[]; | ||
38 | } | ||
39 | ``` | ||
40 | |||
41 | When applying such code action, the editor should insert snippet, with tab stops and placeholder. | ||
42 | At the moment, rust-analyzer guarantees that only a single edit will have `InsertTextFormat.Snippet`. | ||
43 | |||
44 | ### Example | ||
45 | |||
46 | "Add `derive`" code action transforms `struct S;` into `#[derive($0)] struct S;` | ||
47 | |||
48 | ### Unresolved Questions | ||
49 | |||
50 | * Where exactly are `SnippetTextEdit`s allowed (only in code actions at the moment)? | ||
51 | * Can snippets span multiple files (so far, no)? | ||
52 | |||
53 | ## `CodeAction` Groups | ||
54 | |||
55 | **Issue:** https://github.com/microsoft/language-server-protocol/issues/994 | ||
56 | |||
57 | **Client Capability:** `{ "codeActionGroup": boolean }` | ||
58 | |||
59 | If this capability is set, `CodeAction` returned from the server contain an additional field, `group`: | ||
60 | |||
61 | ```typescript | ||
62 | interface CodeAction { | ||
63 | title: string; | ||
64 | group?: string; | ||
65 | ... | ||
66 | } | ||
67 | ``` | ||
68 | |||
69 | All code-actions with the same `group` should be grouped under single (extendable) entry in lightbulb menu. | ||
70 | The set of actions `[ { title: "foo" }, { group: "frobnicate", title: "bar" }, { group: "frobnicate", title: "baz" }]` should be rendered as | ||
71 | |||
72 | ``` | ||
73 | 💡 | ||
74 | +-------------+ | ||
75 | | foo | | ||
76 | +-------------+-----+ | ||
77 | | frobnicate >| bar | | ||
78 | +-------------+-----+ | ||
79 | | baz | | ||
80 | +-----+ | ||
81 | ``` | ||
82 | |||
83 | Alternatively, selecting `frobnicate` could present a user with an additional menu to choose between `bar` and `baz`. | ||
84 | |||
85 | ### Example | ||
86 | |||
87 | ```rust | ||
88 | fn main() { | ||
89 | let x: Entry/*cursor here*/ = todo!(); | ||
90 | } | ||
91 | ``` | ||
92 | |||
93 | Invoking code action at this position will yield two code actions for importing `Entry` from either `collections::HashMap` or `collection::BTreeMap`, grouped under a single "import" group. | ||
94 | |||
95 | ### Unresolved Questions | ||
96 | |||
97 | * Is a fixed two-level structure enough? | ||
98 | * Should we devise a general way to encode custom interaction protocols for GUI refactorings? | ||
99 | |||
100 | ## Parent Module | ||
101 | |||
102 | **Issue:** https://github.com/microsoft/language-server-protocol/issues/1002 | ||
103 | |||
104 | **Server Capability:** `{ "parentModule": boolean }` | ||
105 | |||
106 | This request is send from client to server to handle "Goto Parent Module" editor action. | ||
107 | |||
108 | **Method:** `experimental/parentModule` | ||
109 | |||
110 | **Request:** `TextDocumentPositionParams` | ||
111 | |||
112 | **Response:** `Location | Location[] | LocationLink[] | null` | ||
113 | |||
114 | |||
115 | ### Example | ||
116 | |||
117 | ```rust | ||
118 | // src/main.rs | ||
119 | mod foo; | ||
120 | // src/foo.rs | ||
121 | |||
122 | /* cursor here*/ | ||
123 | ``` | ||
124 | |||
125 | `experimental/parentModule` returns a single `Link` to the `mod foo;` declaration. | ||
126 | |||
127 | ### Unresolved Question | ||
128 | |||
129 | * An alternative would be to use a more general "gotoSuper" request, which would work for super methods, super classes and super modules. | ||
130 | This is the approach IntelliJ Rust is takeing. | ||
131 | However, experience shows that super module (which generally has a feeling of navigation between files) should be separate. | ||
132 | If you want super module, but the cursor happens to be inside an overriden function, the behavior with single "gotoSuper" request is surprising. | ||
133 | |||
134 | ## Join Lines | ||
135 | |||
136 | **Issue:** https://github.com/microsoft/language-server-protocol/issues/992 | ||
137 | |||
138 | **Server Capability:** `{ "joinLines": boolean }` | ||
139 | |||
140 | This request is send from client to server to handle "Join Lines" editor action. | ||
141 | |||
142 | **Method:** `experimental/joinLines` | ||
143 | |||
144 | **Request:** | ||
145 | |||
146 | ```typescript | ||
147 | interface JoinLinesParams { | ||
148 | textDocument: TextDocumentIdentifier, | ||
149 | /// Currently active selections/cursor offsets. | ||
150 | /// This is an array to support multiple cursors. | ||
151 | ranges: Range[], | ||
152 | } | ||
153 | ``` | ||
154 | |||
155 | **Response:** `TextEdit[]` | ||
156 | |||
157 | ### Example | ||
158 | |||
159 | ```rust | ||
160 | fn main() { | ||
161 | /*cursor here*/let x = { | ||
162 | 92 | ||
163 | }; | ||
164 | } | ||
165 | ``` | ||
166 | |||
167 | `experimental/joinLines` yields (curly braces are automagically removed) | ||
168 | |||
169 | ```rust | ||
170 | fn main() { | ||
171 | let x = 92; | ||
172 | } | ||
173 | ``` | ||
174 | |||
175 | ### Unresolved Question | ||
176 | |||
177 | * What is the position of the cursor after `joinLines`? | ||
178 | Currently this is left to editor's discretion, but it might be useful to specify on the server via snippets. | ||
179 | However, it then becomes unclear how it works with multi cursor. | ||
180 | |||
181 | ## On Enter | ||
182 | |||
183 | **Issue:** https://github.com/microsoft/language-server-protocol/issues/1001 | ||
184 | |||
185 | **Server Capability:** `{ "onEnter": boolean }` | ||
186 | |||
187 | This request is send from client to server to handle <kbd>Enter</kbd> keypress. | ||
188 | |||
189 | **Method:** `experimental/onEnter` | ||
190 | |||
191 | **Request:**: `TextDocumentPositionParams` | ||
192 | |||
193 | **Response:** | ||
194 | |||
195 | ```typescript | ||
196 | SnippetTextEdit[] | ||
197 | ``` | ||
198 | |||
199 | ### Example | ||
200 | |||
201 | ```rust | ||
202 | fn main() { | ||
203 | // Some /*cursor here*/ docs | ||
204 | let x = 92; | ||
205 | } | ||
206 | ``` | ||
207 | |||
208 | `experimental/onEnter` returns the following snippet | ||
209 | |||
210 | ```rust | ||
211 | fn main() { | ||
212 | // Some | ||
213 | // $0 docs | ||
214 | let x = 92; | ||
215 | } | ||
216 | ``` | ||
217 | |||
218 | The primary goal of `onEnter` is to handle automatic indentation when opening a new line. | ||
219 | This is not yet implemented. | ||
220 | The secondary goal is to handle fixing up syntax, like continuing doc strings and comments, and escaping `\n` in string literals. | ||
221 | |||
222 | As proper cursor positioning is raison-d'etat for `onEnter`, it uses `SnippetTextEdit`. | ||
223 | |||
224 | ### Unresolved Question | ||
225 | |||
226 | * How to deal with synchronicity of the request? | ||
227 | One option is to require the client to block until the server returns the response. | ||
228 | Another option is to do a OT-style merging of edits from client and server. | ||
229 | A third option is to do a record-replay: client applies heuristic on enter immediatelly, then applies all user's keypresses. | ||
230 | When the server is ready with the response, the client rollbacks all the changes and applies the recorded actions on top of the correct response. | ||
231 | * How to deal with multiple carets? | ||
232 | * Should we extend this to arbitrary typed events and not just `onEnter`? | ||
233 | |||
234 | ## Structural Search Replace (SSR) | ||
235 | |||
236 | **Server Capability:** `{ "ssr": boolean }` | ||
237 | |||
238 | This request is send from client to server to handle structural search replace -- automated syntax tree based transformation of the source. | ||
239 | |||
240 | **Method:** `experimental/ssr` | ||
241 | |||
242 | **Request:** | ||
243 | |||
244 | ```typescript | ||
245 | interface SsrParams { | ||
246 | /// Search query. | ||
247 | /// The specific syntax is specified outside of the protocol. | ||
248 | query: string, | ||
249 | /// If true, only check the syntax of the query and don't compute the actual edit. | ||
250 | parseOnly: bool, | ||
251 | } | ||
252 | ``` | ||
253 | |||
254 | **Response:** | ||
255 | |||
256 | ```typescript | ||
257 | WorkspaceEdit | ||
258 | ``` | ||
259 | |||
260 | ### Example | ||
261 | |||
262 | SSR with query `foo($a:expr, $b:expr) ==>> ($a).foo($b)` will transform, eg `foo(y + 5, z)` into `(y + 5).foo(z)`. | ||
263 | |||
264 | ### Unresolved Question | ||
265 | |||
266 | * Probably needs search without replace mode | ||
267 | * Needs a way to limit the scope to certain files. | ||
268 | |||
269 | ## Matching Brace | ||
270 | |||
271 | **Issue:** https://github.com/microsoft/language-server-protocol/issues/999 | ||
272 | |||
273 | **Server Capability:** `{ "matchingBrace": boolean }` | ||
274 | |||
275 | This request is send from client to server to handle "Matching Brace" editor action. | ||
276 | |||
277 | **Method:** `experimental/matchingBrace` | ||
278 | |||
279 | **Request:** | ||
280 | |||
281 | ```typescript | ||
282 | interface MatchingBraceParams { | ||
283 | textDocument: TextDocumentIdentifier, | ||
284 | /// Position for each cursor | ||
285 | positions: Position[], | ||
286 | } | ||
287 | ``` | ||
288 | |||
289 | **Response:** | ||
290 | |||
291 | ```typescript | ||
292 | Position[] | ||
293 | ``` | ||
294 | |||
295 | ### Example | ||
296 | |||
297 | ```rust | ||
298 | fn main() { | ||
299 | let x: Vec<()>/*cursor here*/ = vec![] | ||
300 | } | ||
301 | ``` | ||
302 | |||
303 | `experimental/matchingBrace` yields the position of `<`. | ||
304 | In many cases, matching braces can be handled by the editor. | ||
305 | However, some cases (like disambiguating between generics and comparison operations) need a real parser. | ||
306 | Moreover, it would be cool if editors didn't need to implement even basic language parsing | ||
307 | |||
308 | ### Unresolved Question | ||
309 | |||
310 | * Should we return a a nested brace structure, to allow paredit-like actions of jump *out* of the current brace pair? | ||
311 | This is how `SelectionRange` request works. | ||
312 | * Alternatively, should we perhaps flag certain `SelectionRange`s as being brace pairs? | ||
313 | |||
314 | ## Runnables | ||
315 | |||
316 | **Issue:** https://github.com/microsoft/language-server-protocol/issues/944 | ||
317 | |||
318 | **Server Capability:** `{ "runnables": { "kinds": string[] } }` | ||
319 | |||
320 | This request is send from client to server to get the list of things that can be run (tests, binaries, `cargo check -p`). | ||
321 | |||
322 | **Method:** `experimental/runnables` | ||
323 | |||
324 | **Request:** | ||
325 | |||
326 | ```typescript | ||
327 | interface RunnablesParams { | ||
328 | textDocument: TextDocumentIdentifier; | ||
329 | /// If null, compute runnables for the whole file. | ||
330 | position?: Position; | ||
331 | } | ||
332 | ``` | ||
333 | |||
334 | **Response:** `Runnable[]` | ||
335 | |||
336 | ```typescript | ||
337 | interface Runnable { | ||
338 | label: string; | ||
339 | /// If this Runnable is associated with a specific function/module, etc, the location of this item | ||
340 | location?: LocationLink; | ||
341 | /// Running things is necessary technology specific, `kind` needs to be advertised via server capabilities, | ||
342 | // the type of `args` is specific to `kind`. The actual running is handled by the client. | ||
343 | kind: string; | ||
344 | args: any; | ||
345 | } | ||
346 | ``` | ||
347 | |||
348 | rust-analyzer supports only one `kind`, `"cargo"`. The `args` for `"cargo"` look like this: | ||
349 | |||
350 | ```typescript | ||
351 | { | ||
352 | workspaceRoot?: string; | ||
353 | cargoArgs: string[]; | ||
354 | executableArgs: string[]; | ||
355 | } | ||
356 | ``` | ||
357 | |||
358 | ## Analyzer Status | ||
359 | |||
360 | **Method:** `rust-analyzer/analyzerStatus` | ||
361 | |||
362 | **Request:** `null` | ||
363 | |||
364 | **Response:** `string` | ||
365 | |||
366 | Returns internal status message, mostly for debugging purposes. | ||
367 | |||
368 | ## Collect Garbage | ||
369 | |||
370 | **Method:** `rust-analyzer/collectGarbage` | ||
371 | |||
372 | **Request:** `null` | ||
373 | |||
374 | **Response:** `null` | ||
375 | |||
376 | Frees some caches. For internal use, and is mostly broken at the moment. | ||
377 | |||
378 | ## Syntax Tree | ||
379 | |||
380 | **Method:** `rust-analyzer/syntaxTree` | ||
381 | |||
382 | **Request:** | ||
383 | |||
384 | ```typescript | ||
385 | interface SyntaxTeeParams { | ||
386 | textDocument: TextDocumentIdentifier, | ||
387 | range?: Range, | ||
388 | } | ||
389 | ``` | ||
390 | |||
391 | **Response:** `string` | ||
392 | |||
393 | Returns textual representation of a parse tree for the file/selected region. | ||
394 | Primarily for debugging, but very useful for all people working on rust-analyzer itself. | ||
395 | |||
396 | ## Expand Macro | ||
397 | |||
398 | **Method:** `rust-analyzer/expandMacro` | ||
399 | |||
400 | **Request:** | ||
401 | |||
402 | ```typescript | ||
403 | interface ExpandMacroParams { | ||
404 | textDocument: TextDocumentIdentifier, | ||
405 | position: Position, | ||
406 | } | ||
407 | ``` | ||
408 | |||
409 | **Response:** | ||
410 | |||
411 | ```typescript | ||
412 | interface ExpandedMacro { | ||
413 | name: string, | ||
414 | expansion: string, | ||
415 | } | ||
416 | ``` | ||
417 | |||
418 | Expands macro call at a given position. | ||
419 | |||
420 | ## Inlay Hints | ||
421 | |||
422 | **Method:** `rust-analyzer/inlayHints` | ||
423 | |||
424 | This request is send from client to server to render "inlay hints" -- virtual text inserted into editor to show things like inferred types. | ||
425 | Generally, the client should re-query inlay hints after every modification. | ||
426 | Note that we plan to move this request to `experimental/inlayHints`, as it is not really Rust-specific, but the current API is not necessary the right one. | ||
427 | Upstream issue: https://github.com/microsoft/language-server-protocol/issues/956 | ||
428 | |||
429 | **Request:** | ||
430 | |||
431 | ```typescript | ||
432 | interface InlayHintsParams { | ||
433 | textDocument: TextDocumentIdentifier, | ||
434 | } | ||
435 | ``` | ||
436 | |||
437 | **Response:** `InlayHint[]` | ||
438 | |||
439 | ```typescript | ||
440 | interface InlayHint { | ||
441 | kind: "TypeHint" | "ParameterHint" | "ChainingHint", | ||
442 | range: Range, | ||
443 | label: string, | ||
444 | } | ||
445 | ``` | ||
diff --git a/docs/dev/lsp-features.md b/docs/dev/lsp-features.md deleted file mode 100644 index 00b0867d7..000000000 --- a/docs/dev/lsp-features.md +++ /dev/null | |||
@@ -1,72 +0,0 @@ | |||
1 | # Supported LSP features | ||
2 | |||
3 | This list documents LSP features, supported by rust-analyzer. | ||
4 | |||
5 | ## General | ||
6 | - [x] [initialize](https://microsoft.github.io/language-server-protocol/specification#initialize) | ||
7 | - [x] [initialized](https://microsoft.github.io/language-server-protocol/specification#initialized) | ||
8 | - [x] [shutdown](https://microsoft.github.io/language-server-protocol/specification#shutdown) | ||
9 | - [ ] [exit](https://microsoft.github.io/language-server-protocol/specification#exit) | ||
10 | - [x] [$/cancelRequest](https://microsoft.github.io/language-server-protocol/specification#cancelRequest) | ||
11 | |||
12 | ## Workspace | ||
13 | - [ ] [workspace/workspaceFolders](https://microsoft.github.io/language-server-protocol/specification#workspace_workspaceFolders) | ||
14 | - [ ] [workspace/didChangeWorkspaceFolders](https://microsoft.github.io/language-server-protocol/specification#workspace_didChangeWorkspaceFolders) | ||
15 | - [x] [workspace/didChangeConfiguration](https://microsoft.github.io/language-server-protocol/specification#workspace_didChangeConfiguration) | ||
16 | - [ ] [workspace/configuration](https://microsoft.github.io/language-server-protocol/specification#workspace_configuration) | ||
17 | - [x] [workspace/didChangeWatchedFiles](https://microsoft.github.io/language-server-protocol/specification#workspace_didChangeWatchedFiles) | ||
18 | - [x] [workspace/symbol](https://microsoft.github.io/language-server-protocol/specification#workspace_symbol) | ||
19 | - [ ] [workspace/applyEdit](https://microsoft.github.io/language-server-protocol/specification#workspace_applyEdit) | ||
20 | |||
21 | ## Text Synchronization | ||
22 | - [x] [textDocument/didOpen](https://microsoft.github.io/language-server-protocol/specification#textDocument_didOpen) | ||
23 | - [x] [textDocument/didChange](https://microsoft.github.io/language-server-protocol/specification#textDocument_didChange) | ||
24 | - [ ] [textDocument/willSave](https://microsoft.github.io/language-server-protocol/specification#textDocument_willSave) | ||
25 | - [ ] [textDocument/willSaveWaitUntil](https://microsoft.github.io/language-server-protocol/specification#textDocument_willSaveWaitUntil) | ||
26 | - [x] [textDocument/didSave](https://microsoft.github.io/language-server-protocol/specification#textDocument_didSave) | ||
27 | - [x] [textDocument/didClose](https://microsoft.github.io/language-server-protocol/specification#textDocument_didClose) | ||
28 | |||
29 | ## Diagnostics | ||
30 | - [x] [textDocument/publishDiagnostics](https://microsoft.github.io/language-server-protocol/specification#textDocument_publishDiagnostics) | ||
31 | |||
32 | ## Lanuguage Features | ||
33 | - [x] [textDocument/completion](https://microsoft.github.io/language-server-protocol/specification#textDocument_completion) | ||
34 | - open close: false | ||
35 | - change: Full | ||
36 | - will save: false | ||
37 | - will save wait until: false | ||
38 | - save: false | ||
39 | - [x] [completionItem/resolve](https://microsoft.github.io/language-server-protocol/specification#completionItem_resolve) | ||
40 | - resolve provider: none | ||
41 | - trigger characters: `:`, `.` | ||
42 | - [x] [textDocument/hover](https://microsoft.github.io/language-server-protocol/specification#textDocument_hover) | ||
43 | - [x] [textDocument/signatureHelp](https://microsoft.github.io/language-server-protocol/specification#textDocument_signatureHelp) | ||
44 | - trigger characters: `(`, `,` | ||
45 | - [ ] [textDocument/declaration](https://microsoft.github.io/language-server-protocol/specification#textDocument_declaration) | ||
46 | - [x] [textDocument/definition](https://microsoft.github.io/language-server-protocol/specification#textDocument_definition) | ||
47 | - [x] [textDocument/typeDefinition](https://microsoft.github.io/language-server-protocol/specification#textDocument_typeDefinition) | ||
48 | - [x] [textDocument/implementation](https://microsoft.github.io/language-server-protocol/specification#textDocument_implementation) | ||
49 | - [x] [textDocument/references](https://microsoft.github.io/language-server-protocol/specification#textDocument_references) | ||
50 | - [x] [textDocument/documentHighlight](https://microsoft.github.io/language-server-protocol/specification#textDocument_documentHighlight) | ||
51 | - [x] [textDocument/documentSymbol](https://microsoft.github.io/language-server-protocol/specification#textDocument_documentSymbol) | ||
52 | - [x] [textDocument/codeAction](https://microsoft.github.io/language-server-protocol/specification#textDocument_codeAction) | ||
53 | - [x] [textDocument/selectionRange](https://github.com/Microsoft/language-server-protocol/issues/613) | ||
54 | - rust-analyzer.syntaxTree | ||
55 | - rust-analyzer.matchingBrace | ||
56 | - rust-analyzer.parentModule | ||
57 | - rust-analyzer.joinLines | ||
58 | - rust-analyzer.run | ||
59 | - rust-analyzer.analyzerStatus | ||
60 | - [x] [textDocument/codeLens](https://microsoft.github.io/language-server-protocol/specification#textDocument_codeLens) | ||
61 | - [x] [codeLens/resolve](https://microsoft.github.io/language-server-protocol/specification#codeLens_resolve) | ||
62 | - [ ] [documentLink/resolve](https://microsoft.github.io/language-server-protocol/specification#documentLink_resolve) | ||
63 | - [ ] [textDocument/documentColor](https://microsoft.github.io/language-server-protocol/specification#textDocument_documentColor) | ||
64 | - [ ] [textDocument/colorPresentation](https://microsoft.github.io/language-server-protocol/specification#textDocument_colorPresentation) | ||
65 | - [x] [textDocument/formatting](https://microsoft.github.io/language-server-protocol/specification#textDocument_formatting) | ||
66 | - [ ] [textDocument/rangeFormatting](https://microsoft.github.io/language-server-protocol/specification#textDocument_rangeFormatting) | ||
67 | - [x] [textDocument/onTypeFormatting](https://microsoft.github.io/language-server-protocol/specification#textDocument_onTypeFormatting) | ||
68 | - first trigger character: `=` | ||
69 | - more trigger character `.` | ||
70 | - [x] [textDocument/rename](https://microsoft.github.io/language-server-protocol/specification#textDocument_rename) | ||
71 | - [x] [textDocument/prepareRename](https://microsoft.github.io/language-server-protocol/specification#textDocument_prepareRename) | ||
72 | - [x] [textDocument/foldingRange](https://microsoft.github.io/language-server-protocol/specification#textDocument_foldingRange) | ||
diff --git a/docs/dev/syntax.md b/docs/dev/syntax.md index 33973ffec..c2864bbbc 100644 --- a/docs/dev/syntax.md +++ b/docs/dev/syntax.md | |||
@@ -64,7 +64,7 @@ struct Token { | |||
64 | } | 64 | } |
65 | ``` | 65 | ``` |
66 | 66 | ||
67 | All the difference bettwen the above sketch and the real implementation are strictly due to optimizations. | 67 | All the difference between the above sketch and the real implementation are strictly due to optimizations. |
68 | 68 | ||
69 | Points of note: | 69 | Points of note: |
70 | * The tree is untyped. Each node has a "type tag", `SyntaxKind`. | 70 | * The tree is untyped. Each node has a "type tag", `SyntaxKind`. |
@@ -72,7 +72,7 @@ Points of note: | |||
72 | * Trivia and non-trivia tokens are not distinguished on the type level. | 72 | * Trivia and non-trivia tokens are not distinguished on the type level. |
73 | * Each token carries its full text. | 73 | * Each token carries its full text. |
74 | * The original text can be recovered by concatenating the texts of all tokens in order. | 74 | * The original text can be recovered by concatenating the texts of all tokens in order. |
75 | * Accessing a child of particular type (for example, parameter list of a function) generarly involves linerary traversing the children, looking for a specific `kind`. | 75 | * Accessing a child of particular type (for example, parameter list of a function) generally involves linerary traversing the children, looking for a specific `kind`. |
76 | * Modifying the tree is roughly `O(depth)`. | 76 | * Modifying the tree is roughly `O(depth)`. |
77 | We don't make special efforts to guarantree that the depth is not liner, but, in practice, syntax trees are branchy and shallow. | 77 | We don't make special efforts to guarantree that the depth is not liner, but, in practice, syntax trees are branchy and shallow. |
78 | * If mandatory (grammar wise) node is missing from the input, it's just missing from the tree. | 78 | * If mandatory (grammar wise) node is missing from the input, it's just missing from the tree. |
@@ -123,7 +123,7 @@ To more compactly store the children, we box *both* interior nodes and tokens, a | |||
123 | `Either<Arc<Node>, Arc<Token>>` as a single pointer with a tag in the last bit. | 123 | `Either<Arc<Node>, Arc<Token>>` as a single pointer with a tag in the last bit. |
124 | 124 | ||
125 | To avoid allocating EVERY SINGLE TOKEN on the heap, syntax trees use interning. | 125 | To avoid allocating EVERY SINGLE TOKEN on the heap, syntax trees use interning. |
126 | Because the tree is fully imutable, it's valid to structuraly share subtrees. | 126 | Because the tree is fully immutable, it's valid to structurally share subtrees. |
127 | For example, in `1 + 1`, there will be a *single* token for `1` with ref count 2; the same goes for the ` ` whitespace token. | 127 | For example, in `1 + 1`, there will be a *single* token for `1` with ref count 2; the same goes for the ` ` whitespace token. |
128 | Interior nodes are shared as well (for example in `(1 + 1) * (1 + 1)`). | 128 | Interior nodes are shared as well (for example in `(1 + 1) * (1 + 1)`). |
129 | 129 | ||
@@ -134,8 +134,8 @@ Currently, the interner is created per-file, but it will be easy to use a per-th | |||
134 | 134 | ||
135 | We use a `TextSize`, a newtyped `u32`, to store the length of the text. | 135 | We use a `TextSize`, a newtyped `u32`, to store the length of the text. |
136 | 136 | ||
137 | We currently use `SmolStr`, an small object optimized string to store text. | 137 | We currently use `SmolStr`, a small object optimized string to store text. |
138 | This was mostly relevant *before* we implmented tree interning, to avoid allocating common keywords and identifiers. We should switch to storing text data alongside the interned tokens. | 138 | This was mostly relevant *before* we implemented tree interning, to avoid allocating common keywords and identifiers. We should switch to storing text data alongside the interned tokens. |
139 | 139 | ||
140 | #### Alternative designs | 140 | #### Alternative designs |
141 | 141 | ||
@@ -162,12 +162,12 @@ Explicit trivia nodes, like in `rowan`, are used by IntelliJ. | |||
162 | 162 | ||
163 | ##### Accessing Children | 163 | ##### Accessing Children |
164 | 164 | ||
165 | As noted before, accesing a specific child in the node requires a linear traversal of the children (though we can skip tokens, beacuse the tag is encoded in the pointer itself). | 165 | As noted before, accessing a specific child in the node requires a linear traversal of the children (though we can skip tokens, because the tag is encoded in the pointer itself). |
166 | It is possible to recover O(1) access with another representation. | 166 | It is possible to recover O(1) access with another representation. |
167 | We explicitly store optional and missing (required by the grammar, but not present) nodes. | 167 | We explicitly store optional and missing (required by the grammar, but not present) nodes. |
168 | That is, we use `Option<Node>` for children. | 168 | That is, we use `Option<Node>` for children. |
169 | We also remove trivia tokens from the tree. | 169 | We also remove trivia tokens from the tree. |
170 | This way, each child kind genrerally occupies a fixed position in a parent, and we can use index access to fetch it. | 170 | This way, each child kind generally occupies a fixed position in a parent, and we can use index access to fetch it. |
171 | The cost is that we now need to allocate space for all not-present optional nodes. | 171 | The cost is that we now need to allocate space for all not-present optional nodes. |
172 | So, `fn foo() {}` will have slots for visibility, unsafeness, attributes, abi and return type. | 172 | So, `fn foo() {}` will have slots for visibility, unsafeness, attributes, abi and return type. |
173 | 173 | ||
@@ -193,7 +193,7 @@ Modeling this with immutable trees is possible, but annoying. | |||
193 | ### Syntax Nodes | 193 | ### Syntax Nodes |
194 | 194 | ||
195 | A function green tree is not super-convenient to use. | 195 | A function green tree is not super-convenient to use. |
196 | The biggest problem is acessing parents (there are no parent pointers!). | 196 | The biggest problem is accessing parents (there are no parent pointers!). |
197 | But there are also "identify" issues. | 197 | But there are also "identify" issues. |
198 | Let's say you want to write a code which builds a list of expressions in a file: `fn collect_exrepssions(file: GreenNode) -> HashSet<GreenNode>`. | 198 | Let's say you want to write a code which builds a list of expressions in a file: `fn collect_exrepssions(file: GreenNode) -> HashSet<GreenNode>`. |
199 | For the input like | 199 | For the input like |
@@ -207,7 +207,7 @@ fn main() { | |||
207 | } | 207 | } |
208 | ``` | 208 | ``` |
209 | 209 | ||
210 | both copies of the `x + 2` expression are representing by equal (and, with interning in mind, actualy the same) green nodes. | 210 | both copies of the `x + 2` expression are representing by equal (and, with interning in mind, actually the same) green nodes. |
211 | Green trees just can't differentiate between the two. | 211 | Green trees just can't differentiate between the two. |
212 | 212 | ||
213 | `SyntaxNode` adds parent pointers and identify semantics to green nodes. | 213 | `SyntaxNode` adds parent pointers and identify semantics to green nodes. |
@@ -285,9 +285,9 @@ They also point to the parent (and, consequently, to the root) with an owning `R | |||
285 | In other words, one needs *one* arc bump when initiating a traversal. | 285 | In other words, one needs *one* arc bump when initiating a traversal. |
286 | 286 | ||
287 | To get rid of allocations, `rowan` takes advantage of `SyntaxNode: !Sync` and uses a thread-local free list of `SyntaxNode`s. | 287 | To get rid of allocations, `rowan` takes advantage of `SyntaxNode: !Sync` and uses a thread-local free list of `SyntaxNode`s. |
288 | In a typical traversal, you only directly hold a few `SyntaxNode`s at a time (and their ancesstors indirectly), so a free list proportional to the depth of the tree removes all allocations in a typical case. | 288 | In a typical traversal, you only directly hold a few `SyntaxNode`s at a time (and their ancestors indirectly), so a free list proportional to the depth of the tree removes all allocations in a typical case. |
289 | 289 | ||
290 | So, while traversal is not exactly incrementing a pointer, it's still prety cheep: tls + rc bump! | 290 | So, while traversal is not exactly incrementing a pointer, it's still pretty cheap: TLS + rc bump! |
291 | 291 | ||
292 | Traversal also yields (cheap) owned nodes, which improves ergonomics quite a bit. | 292 | Traversal also yields (cheap) owned nodes, which improves ergonomics quite a bit. |
293 | 293 | ||
@@ -308,15 +308,15 @@ struct SyntaxData { | |||
308 | } | 308 | } |
309 | ``` | 309 | ``` |
310 | 310 | ||
311 | This allows using true pointer equality for comparision of identities of `SyntaxNodes`. | 311 | This allows using true pointer equality for comparison of identities of `SyntaxNodes`. |
312 | rust-analyzer used to have this design as well, but since we've switch to cursors. | 312 | rust-analyzer used to have this design as well, but we've since switched to cursors. |
313 | The main problem with memoizing the red nodes is that it more than doubles the memory requirenments for fully realized syntax trees. | 313 | The main problem with memoizing the red nodes is that it more than doubles the memory requirements for fully realized syntax trees. |
314 | In contrast, cursors generally retain only a path to the root. | 314 | In contrast, cursors generally retain only a path to the root. |
315 | C# combats increased memory usage by using weak references. | 315 | C# combats increased memory usage by using weak references. |
316 | 316 | ||
317 | ### AST | 317 | ### AST |
318 | 318 | ||
319 | `GreenTree`s are untyped and homogeneous, because it makes accomodating error nodes, arbitrary whitespace and comments natural, and because it makes possible to write generic tree traversals. | 319 | `GreenTree`s are untyped and homogeneous, because it makes accommodating error nodes, arbitrary whitespace and comments natural, and because it makes possible to write generic tree traversals. |
320 | However, when working with a specific node, like a function definition, one would want a strongly typed API. | 320 | However, when working with a specific node, like a function definition, one would want a strongly typed API. |
321 | 321 | ||
322 | This is what is provided by the AST layer. AST nodes are transparent wrappers over untyped syntax nodes: | 322 | This is what is provided by the AST layer. AST nodes are transparent wrappers over untyped syntax nodes: |
@@ -397,7 +397,7 @@ impl HasVisbility for FnDef { | |||
397 | Points of note: | 397 | Points of note: |
398 | 398 | ||
399 | * Like `SyntaxNode`s, AST nodes are cheap to clone pointer-sized owned values. | 399 | * Like `SyntaxNode`s, AST nodes are cheap to clone pointer-sized owned values. |
400 | * All "fields" are optional, to accomodate incomplete and/or erroneous source code. | 400 | * All "fields" are optional, to accommodate incomplete and/or erroneous source code. |
401 | * It's always possible to go from an ast node to an untyped `SyntaxNode`. | 401 | * It's always possible to go from an ast node to an untyped `SyntaxNode`. |
402 | * It's possible to go in the opposite direction with a checked cast. | 402 | * It's possible to go in the opposite direction with a checked cast. |
403 | * `enum`s allow modeling of arbitrary intersecting subsets of AST types. | 403 | * `enum`s allow modeling of arbitrary intersecting subsets of AST types. |
@@ -437,13 +437,13 @@ impl GreenNodeBuilder { | |||
437 | } | 437 | } |
438 | ``` | 438 | ``` |
439 | 439 | ||
440 | The parser, ultimatelly, needs to invoke the `GreenNodeBuilder`. | 440 | The parser, ultimately, needs to invoke the `GreenNodeBuilder`. |
441 | There are two principal sources of inputs for the parser: | 441 | There are two principal sources of inputs for the parser: |
442 | * source text, which contains trivia tokens (whitespace and comments) | 442 | * source text, which contains trivia tokens (whitespace and comments) |
443 | * token trees from macros, which lack trivia | 443 | * token trees from macros, which lack trivia |
444 | 444 | ||
445 | Additionaly, input tokens do not correspond 1-to-1 with output tokens. | 445 | Additionally, input tokens do not correspond 1-to-1 with output tokens. |
446 | For example, two consequtive `>` tokens might be glued, by the parser, into a single `>>`. | 446 | For example, two consecutive `>` tokens might be glued, by the parser, into a single `>>`. |
447 | 447 | ||
448 | For these reasons, the parser crate defines a callback interfaces for both input tokens and output trees. | 448 | For these reasons, the parser crate defines a callback interfaces for both input tokens and output trees. |
449 | The explicit glue layer then bridges various gaps. | 449 | The explicit glue layer then bridges various gaps. |
@@ -491,7 +491,7 @@ Syntax errors are not stored directly in the tree. | |||
491 | The primary motivation for this is that syntax tree is not necessary produced by the parser, it may also be assembled manually from pieces (which happens all the time in refactorings). | 491 | The primary motivation for this is that syntax tree is not necessary produced by the parser, it may also be assembled manually from pieces (which happens all the time in refactorings). |
492 | Instead, parser reports errors to an error sink, which stores them in a `Vec`. | 492 | Instead, parser reports errors to an error sink, which stores them in a `Vec`. |
493 | If possible, errors are not reported during parsing and are postponed for a separate validation step. | 493 | If possible, errors are not reported during parsing and are postponed for a separate validation step. |
494 | For example, parser accepts visibility modifiers on trait methods, but then a separate tree traversal flags all such visibilites as erroneous. | 494 | For example, parser accepts visibility modifiers on trait methods, but then a separate tree traversal flags all such visibilities as erroneous. |
495 | 495 | ||
496 | ### Macros | 496 | ### Macros |
497 | 497 | ||
@@ -501,7 +501,7 @@ Specifically, `TreeSink` constructs the tree in lockstep with draining the origi | |||
501 | In the process, it records which tokens of the tree correspond to which tokens of the input, by using text ranges to identify syntax tokens. | 501 | In the process, it records which tokens of the tree correspond to which tokens of the input, by using text ranges to identify syntax tokens. |
502 | The end result is that parsing an expanded code yields a syntax tree and a mapping of text-ranges of the tree to original tokens. | 502 | The end result is that parsing an expanded code yields a syntax tree and a mapping of text-ranges of the tree to original tokens. |
503 | 503 | ||
504 | To deal with precedence in cases like `$expr * 1`, we use special invisible parenthesis, which are explicitelly handled by the parser | 504 | To deal with precedence in cases like `$expr * 1`, we use special invisible parenthesis, which are explicitly handled by the parser |
505 | 505 | ||
506 | ### Whitespace & Comments | 506 | ### Whitespace & Comments |
507 | 507 | ||