Rework features documentation

docs/_static/theme_overrides.css

@@ -0,0 +1,6 @@
+/* Fix table wrapping https://github.com/readthedocs/sphinx_rtd_theme/issues/117 */
+@media screen and (min-width: 768px) {
+	.wy-table-responsive table td, .wy-table-responsive table th {
+	  white-space: normal !important;
+	}
+}

docs/conf.py

@@ -86,4 +86,9 @@
 
 # Enable linking to an anchor of a relative page
 # See https://github.com/executablebooks/MyST-Parser/issues/443
-myst_heading_anchors = 2
+myst_heading_anchors = 3
+
+# -- Custom Document processing ----------------------------------------------
+
+def setup(app):
+    app.add_css_file("theme_overrides.css")

docs/features.md

@@ -1,58 +1,260 @@
 # Features
 
-You can watch demos for some of these features [below](#demos).
-
-- Warning and error diagnostics from GHC
-- Type information and documentation on hover, [including your own comments](./configuration.md#how-to-show-local-documentation-on-hover).
-- Jump to definition: [for now only for local code definitions](https://github.com/haskell/haskell-language-server/issues/708)
-- Document symbols
-- Highlight references in document
-- Code completion
-- Formatting via [Brittany](https://github.com/lspitzner/brittany), [Floskell](https://github.com/ennocramer/floskell), [Fourmolu](https://github.com/fourmolu/fourmolu), [Ormolu](https://github.com/tweag/ormolu) or [Stylish Haskell](https://github.com/haskell/stylish-haskell)
-- [Code evaluation](#code-evaluation), see its [Tutorial](https://github.com/haskell/haskell-language-server/blob/master/plugins/hls-eval-plugin/README.md)
-- [Integration with](#retrie-integration) [retrie](https://hackage.haskell.org/package/retrie), a powerful, easy-to-use codemodding tool
-- [Code lenses for explicit import lists](#explicit-import-lists)
-- [Generate functions from type signatures, and intelligently complete holes](#wingman) using [Wingman (tactics)](https://github.com/haskell/haskell-language-server/tree/master/plugins/hls-tactics-plugin)
-- [Integration](#hlint) with [hlint](https://github.com/ndmitchell/hlint), the most used haskell linter, to show diagnostics and apply hints via [apply-refact](https://github.com/mpickering/apply-refact)
-- [Module name suggestions](#module-names) for insertion or correction
-- [Call hierarchy support](#call-hierarchy)
-- [Qualify names from an import declaration](#qualify-imported-names) in your code
-- [Suggest alternate numeric formats](#alternate-number-formatting)
-
-## Demos
-
-### Code evaluation
+This table gives a summary of the features that HLS supports.
+Many of these are standard LSP features, but a lot of special features are provided as [code actions](#code-actions) and [code lenses](#code-lenses).
 
-![Eval Demo](https://raw.githubusercontent.com/haskell/haskell-language-server/master/plugins/hls-eval-plugin/demo.gif)
+| Feature                                             | [LSP method](./what-is-hls.md#lsp-terminology)                                                    |
+|-----------------------------------------------------|---------------------------------------------------------------------------------------------------|
+| [Diagnostics](#diagnostics)                         | `textDocument/publishDiagnostics`                                                                 |
+| [Hovers](#hovers)                                   | `textDocument/hover`                                                                              |
+| [Jump to definition](#jump-to-definition)           | `textDocument/definition`                                                                         |
+| [Jump to type definition](#jump-to-type-definition) | `textDocument/typeDefinition`                                                                     |
+| [Find references](#find-references)                 | `textDocument/references`                                                                         |
+| [Completions](#completions)                         | `textDocument/completion`                                                                         |
+| [Formatting](#formatting)                           | `textDocument/formatting`, `textDocument/rangeFormatting`                                         |
+| [Document symbols](#document-symbols)               | `textDocument/documentSymbol`                                                                     |
+| [Workspace symbols](#workspace-symbols)             | `workspace/symbol`                                                                                |
+| [Call hierarchy](#call-hierarchy)                   | `textDocument/prepareCallHierarchy`, `callHierarchy/incomingCalls`, `callHierarchy/outgoingCalls` |
+| [Highlight references](#highlight-references)       | `textDocument/documentHighlight`                                                                  |
+| [Code actions](#code-actions)                       | `textDocument/codeAction`                                                                         |
+| [Code lenses](#code-lenses)                         | `textDocument/codeLens`                                                                           |
 
-### Retrie integration
+The individual sections below also identify which [HLS plugin](./what-is-hls.md#hls-plugins) is responsible for providing the given functionality, which is useful if you want to raise an issue report or contribute!
+Additionally, not all plugins are supported on all versions of GHC, see the [GHC version support page](supported-versions.md) for details.
 
-![Retrie Demo](https://i.imgur.com/Ev7B87k.gif)
+## Diagnostics
 
-### Explicit import lists
+### GHC compiler errors and warnings
+Provided by: `ghcide`
 
-![Imports code lens Demo](https://imgur.com/pX9kvY4.gif)
+Provides errors and warnings from GHC as diagnostics.
 
-### Wingman
+### Hlint hints
+Provided by: `hls-hlint-plugin`
 
-![Wingman Demo](https://user-images.githubusercontent.com/307223/92657198-3d4be400-f2a9-11ea-8ad3-f541c8eea891.gif)
+Provides hlint hints as diagnostics.
 
-### Hlint
+## Hovers
+Provided by: `ghcide`
 
-![Hlint Demo](https://user-images.githubusercontent.com/54035/110860028-8f9fa900-82bc-11eb-9fe5-6483d8bb95e6.gif)
+Type information and documentation on hover, [including from local definitions](./configuration.md#how-to-show-local-documentation-on-hover).
 
-### Module names
+## Jump to definition
+Provided by: `ghcide`
 
-![Module Name Demo](https://user-images.githubusercontent.com/54035/110860755-78ad8680-82bd-11eb-9845-9ea4b1cc1f76.gif)
+Jump to the definition of a name.
+
+Known limitations:
+- Only works for [local definitions](https://github.com/haskell/haskell-language-server/issues/708).
+
+## Jump to type definition
+Provided by: `ghcide`
+
+Known limitations:
+- Only works for [local definitions](https://github.com/haskell/haskell-language-server/issues/708).
+
+## Find references
+Provided by: `ghcide`
+
+Find references to a name within the project.
+
+## Completions
+
+### Code completions
+Provided by: `ghcide`
+
+- Completion of names from qualified imports.
+- Completion of names from non-imported modules.
+
+### Pragma completions
+Provided by: `hls-pragmas-plugin`
+
+Completions for language pragmas.
+
+## Formatting
+Format your code with various Haskell code formatters.
+
+| Formatter       | Provided by                  |
+|-----------------|------------------------------|
+| Brittany        | `hls-brittany-plugin`        |
+| Floskell        | `hls-floskell-plugin`        |
+| Fourmolu        | `hls-fourmolu-plugin`        |
+| Ormolu          | `hls-ormolu-plugin`          |
+| Stylish Haskell | `hls-stylish-haskell-plugin` |
+
+## Document symbols
+Provided by: `ghcide`
+
+Provides listing of the symbols defined in a module, used to power outline displays.
+
+## Workspace symbols
+Provided by: `ghcide`
+
+Provides listing of the symbols defined in the project, used to power searches.
 
-### Call hierarchy
+## Call hierarchy
+Provided by: `hls-call-hierarchy-plugin`
+
+Shows ingoing and outgoing calls for a function.
 
 ![Call Hierarchy in VSCode](https://github.com/haskell/haskell-language-server/raw/2857eeece0398e1cd4b2ffb6069b05c4d2308b39/plugins/hls-call-hierarchy-plugin/call-hierarchy-in-vscode.gif)
 
+## Highlight references
+Provided by: `ghcide`
+
+Highlights references to a name in a document.
+
+## Code actions
+
+### Insert missing pragmas
+Provided by: `hls-pragma-plugin`
+
+Code action kind: `quickfix`
+
+Inserts missing pragmas needed by GHC.
+
+### Apply Hlint fixes
+Provided by: `hls-hlint-plugin`
+
+Code action kind: `quickfix`
+
+Applies hints, either individually or for the whole file.
+Uses [apply-refact](https://github.com/mpickering/apply-refact).
+
+![Hlint Demo](https://user-images.githubusercontent.com/54035/110860028-8f9fa900-82bc-11eb-9fe5-6483d8bb95e6.gif)
+
+Known limitations:
+- May have strange behaviour in files with CPP, since `apply-refact` does not support CPP.
+
+### Make import lists fully explicit
+Provided by: `hls-explicit-imports-plugin`
+
+Code action kind: `quickfix.literals.style`
+
+Make import lists fully explicit (same as the code lens).
+
 ### Qualify imported names
+Provided by: `hls-qualify-imported-names-plugin`
+
+Code action kind: `quickfix`
+
+Rewrites imported names to be qualified.
 
 ![Qualify Imported Names Demo](../plugins/hls-qualify-imported-names-plugin/qualify-imported-names-demo.gif)
+
+For usage see the ![readme](../plugins/hls-qualify-imported-names-plugin/README.md).
+
+### Refine import
+Provided by: `hls-refine-imports-plugin`
+
+Code action kind: `quickfix.import.refine`
+
+Refines imports to more specific modules when names are re-exported (same as the code lens).
+
+### Add missing class methods
+Provided by: `hls-class-plugin`
 
-### Alternate Number Formatting
+Code action kind: `quickfix`
+
+Adds placeholders for missing class methods in a class instance definition.
+
+### Unfold definition
+Provided by: `hls-retrie-plugin`
+
+Code action kind: `refactor.extract`
+
+Extracts a definition from the code.
+
+### Fold definition
+Provided by: `hls-retrie-plugin`
+
+Code action kind: `refactor.inline`
+
+Inlines a definition from the code.
+
+![Retrie Demo](https://i.imgur.com/Ev7B87k.gif)
+
+### Insert contents of Template Haskell splice
+Provided by: `hls-splice-plugin`
+
+Code action kind: `refactor.rewrite`
+
+Evaluates a Template Haskell splice and inserts the resulting code in its place.
+
+### Convert numbers to alternative formats
+Provided by: `hls-alternate-number-format-plugin`
+
+Code action kind: `quickfix.literals.style`
+
+Converts numeric literals to different formats.
 
 ![Alternate Number Format Demo](../plugins/hls-alternate-number-format-plugin/HLSAll.gif)
+
+### Add Haddock comments
+Provided by: `hls-haddock-comments-plugin`
+
+Code action kind: `quickfix`
+
+Adds Haddock comments for function arguments.
+
+### Wingman
+Status: Not supported on GHC 9.2
+
+Provided by: `hls-tactics-plugin`
+
+Provides a variety of code actions for interactive code development, see https://haskellwingman.dev/ for more details.
+
+![Wingman Demo](https://user-images.githubusercontent.com/307223/92657198-3d4be400-f2a9-11ea-8ad3-f541c8eea891.gif)
+
+## Code lenses
+
+### Add type signature
+Provided by: `ghcide`
+
+Shows the type signature for bindings without type signatures, and adds it with a click.
+
+### Evaluation code snippets in comments
+Provided by: `hls-eval-plugin`
+
+Evaluates code blocks in comments with a click. [Tutorial](https://github.com/haskell/haskell-language-server/blob/master/plugins/hls-eval-plugin/README.md).
+
+![Eval Demo](https://raw.githubusercontent.com/haskell/haskell-language-server/master/plugins/hls-eval-plugin/demo.gif)
+
+### Make import lists fully explicit
+Provided by: `hls-explicit-imports-plugin`
+
+Shows fully explicit import lists and rewrites them with a click (same as the code action).
+
+![Imports code lens Demo](https://imgur.com/pX9kvY4.gif)
+
+### Refine import
+Provided by: `hls-refine-imports-plugin`
+
+Shows refined imports and applies them with a click (same as the code action).
+
+### Fix module names
+Provided by: `hls-module-name-plugin`
+
+Shows module name matching file path, and applies it with a click.
+
+![Module Name Demo](https://user-images.githubusercontent.com/54035/110860755-78ad8680-82bd-11eb-9845-9ea4b1cc1f76.gif)
+
+## Missing features
+
+The following features are supported by the LSP specification but not implemented in HLS.
+Contributions welcome!
+
+| Feature                | Status                                                                                   | [LSP method](./what-is-hls.md#lsp-terminology)      |
+|------------------------|------------------------------------------------------------------------------------------|-----------------------------------------------------|
+| Signature help         | Unimplemented                                                                            | `textDocument/signatureHelp`                        |
+| Jump to declaration    | Unclear if useful                                                                        | `textDocument/declaration`                          |
+| Jump to implementation | Unclear if useful                                                                        | `textDocument/implementation`                       |
+| Renaming               | [Parital implementation](https://github.com/haskell/haskell-language-server/issues/2193) | `textDocument/rename`, `textDocument/prepareRename` |
+| Folding                | Unimplemented                                                                            | `textDocument/foldingRange`                         |
+| Selection range        | Unimplemented                                                                            | `textDocument/selectionRange`                       |
+| Semantic tokens        | Unimplemented                                                                            | `textDocument/semanticTokens`                       |
+| Linked editing         | Unimplemented                                                                            | `textDocument/linkedEditingRange`                   |
+| Document links         | Unimplemented                                                                            | `textDocument/documentLink`                         |
+| Document color         | Unclear if useful                                                                        | `textDocument/documentColor`                        |
+| Color presentation     | Unclear if useful                                                                        | `textDocument/colorPresentation`                    |
+| Monikers               | Unclear if useful                                                                        | `textDocument/moniker`                              |

docs/supported-versions.md

@@ -26,6 +26,31 @@ GHC versions not in the list have never been supported by HLS, or are not planne
 
 The policy for when we deprecate support for versions of GHC is given below. The table reflects that, but we may decide to deviate from it for good reasons.
 
+Additionally, some plugins do not have support for some GHC versions, as shown in the following table.
+As such, the functionality provided by those plugins is not available in HLS when using a GHC version which they do not support.
+
+| Plugin                              | Unsupported GHC versions |
+|-------------------------------------|--------------------------|
+| `hls-alternate-number-plugin`       | 9.2                      |
+| `hls-brittany-plugin`               | 9.2                      |
+| `hls-call-hierarchy-plugin`         |                          |
+| `hls-class-plugin`                  | 9.2                      |
+| `hls-eval-plugin`                   | 9.2                      |
+| `hls-explicit-imports-plugin`       |                          |
+| `hls-floskell-plugin`               |                          |
+| `hls-fourmolu-plugin`               |                          |
+| `hls-haddock-comments-plugin`       | 9.2                      |
+| `hls-hlint-plugin`                  | 9.2                      |
+| `hls-module-name-plugin`            |                          |
+| `hls-ormolu-plugin`                 |                          |
+| `hls-pragmas-plugin`                |                          |
+| `hls-qualify-imported-names-plugin` |                          |
+| `hls-refine-imports-plugin`         |                          |
+| `hls-retrie-plugin`                 | 9.2                      |
+| `hls-splice-plugin`                 | 9.2                      |
+| `hls-stylish-haskell-plugin`        | 9.0, 9.2                 |
+| `hls-tactics-plugin`                | 9.2                      |
+
 ### Using deprecated GHC versions
 
 Users who want to use a GHC version which is not supported by the latest HLS can still use older versions of HLS (consult the version support table above to identify the appropriate HLS version).

docs/what-is-hls.md

@@ -33,6 +33,7 @@ Here are a few pieces of jargon that you may come across in the HLS docs or when
 - *Completion item*: An item that can be inserted into the text, including its metadata.
 - *Diagnostic*: Any information about the project that is shown in the editor, including errors, warnings, and hints from tools such as hlint.
 - *Semantic highlighting*: Special syntax highlighting performed by the server.
+- *Method*: A LSP method is a function in the LSP protocol that the client can invoke to perform some action, e.g. ask for completions at a point.
 
 ## haskell-language-server