Language Server

.gitignore

@@ -4,7 +4,6 @@
 .DS_Store
 .vs/
 .vscode/
-.koka/
 node_modules/
 out/
 bundle/
@@ -30,3 +29,5 @@ test.kk
 /*.cmake
 bench
 test/bench
+.koka
+scratch

koka.cabal

@@ -1,6 +1,6 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.35.0.
+-- This file has been generated from package.yaml by hpack version 0.35.2.
 --
 -- see: https://github.com/sol/hpack
 
@@ -92,6 +92,16 @@ executable koka
       Kind.Repr
       Kind.Synonym
       Kind.Unify
+      LanguageServer.Conversions
+      LanguageServer.Handler.Completion
+      LanguageServer.Handler.Definition
+      LanguageServer.Handler.DocumentSymbol
+      LanguageServer.Handler.Hover
+      LanguageServer.Handler.Initialized
+      LanguageServer.Handler.TextDocument
+      LanguageServer.Handlers
+      LanguageServer.Monad
+      LanguageServer.Run
       Lib.JSON
       Lib.PPrint
       Lib.Printer
@@ -144,10 +154,15 @@ executable koka
       array
     , base >=4.9
     , bytestring
+    , co-log-core
     , containers
     , directory
     , isocline >=1.0.6
+    , lens
+    , lsp
     , mtl
+    , network
+    , network-simple
     , parsec
     , process
     , text
@@ -170,6 +185,7 @@ test-suite koka-test
       array
     , base >=4.9
     , bytestring
+    , co-log-core
     , containers
     , directory
     , extra
@@ -178,7 +194,11 @@ test-suite koka-test
     , hspec-core
     , isocline >=1.0.6
     , json
+    , lens
+    , lsp
     , mtl
+    , network
+    , network-simple
     , parsec
     , process
     , regex-compat >=0.95.2.1

package.yaml

@@ -22,12 +22,17 @@ dependencies:
   - array
   - bytestring
   - containers
+  - co-log-core
   - directory
+  - lens
+  - lsp
   - mtl
   - parsec
   - process
   - text
   - time
+  - network-simple
+  - network
   - isocline >= 1.0.6
 
 executables:

readme.md

@@ -276,9 +276,6 @@ More advanced projects:
 * [x] Update the JavaScript backend to 1) use modern modules instead of amdefine, 2) use the new bigints instead of
   bigint.js, and 3) add support for int64. (landed in the `dev` branch)
 * [x] Port `std/text/regex` from v1 (using PCRE)
-* [ ] A language server for Visual Studio Code and Atom. Koka can already generate a
-  typed [range map](src/Syntax/RangeMap.hs) so this should be managable. Partially done: see PR #100 (by @fwcd) -- it just
-  needs work on packaging it to make it easy to build and install as part of the Koka installer.
 * [ ] Package management of Koka modules.
 * [x] Compile to WASM (using emscripten on the current C backend)
 * [ ] Improve compilation of local state to use local variables directly (in C) without allocation. Tricky though due to multiple resumptions.
@@ -315,6 +312,17 @@ The following is the immediate todo list to be completed in the coming months:
 * [ ] Port `std/async` (using `libuv`).
 * [ ] Proper overloading with (a form of) type classes. (in design phase).
 
+LSP Related Tasks:
+* [ ] Generate completions for effect handlers (with empty bodies of all the functions)
+* [ ] Generate show / (==) for datatypes
+* [ ] Find References
+* [ ] Generate Type Annotations
+
+Extension Related Tasks:
+
+VSCode:
+* [ ] Add support for debugging an executable
+
 Contact me if you are interested in tackling some of these :-)
 
 # Build Notes
@@ -457,6 +465,51 @@ $ out\v2.0.5\cl-release\test_bench_koka_rbtree --kktime
 info: elapsed: 1.483s, user: 1.484s, sys: 0.000s, rss: 164mb
 ```
 
+## Language Server
+
+The language server is started by running the koka compilter with the --language-server flag
+and then connecting to it with a client that supports the Language Server Protocol (LSP)
+
+For example, using VSCode, install the Koka extension or run the extension debug configuration in the project.
+Open up a folder and start editing `.kk` files. (The extension finds the koka executable and then automatically starts the language server for you).
+
+The VSCode extension searches in the following locations for the koka executable:
+- A koka development environment in ~/koka
+- A local install ~/.local/bin
+- The PATH environment variable
+
+To specify the command to start the language server manually, such as to provide additional flags to the koka compiler override the `koka.languageServer.command` VSCode setting.
+To specify the current working directory to run the compiler from use the `koka.languageServer.cwd` setting. If there are problems with the language server, you can enable the `koka.languageServer.trace.server` setting to see the language server logs, or turn off the language server by setting the `koka.languageServer.enable` setting to `false`.
+
+To develop the language server, you can use this VSCode debug configuration (add the configuration to .vscode/launch.json).
+
+```json
+{
+  // Use IntelliSense to learn about possible attributes.
+  // Hover to view descriptions of existing attributes.
+  // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+  "version": "0.2.0",
+  "configurations": [
+    {
+        "name": "Launch Extension",
+        "request": "launch",
+        "type": "extensionHost",
+        "args": [
+            "--extensionDevelopmentPath=${workspaceFolder}/support/vscode/koka.language-koka"
+        ],
+        "outFiles": [
+            "${workspaceFolder}/support/vscode/koka.language-koka/out/**/*.js"
+        ]
+    }
+]
+}
+```
+
+- Run `npm install && npm run build` in the `support/vscode/koka.language-koka` directory 
+- Update the LSP server in the `src/LanguageServer` directory with your changes
+- Run `stack build` 
+- Restart the debug configuration and make sure a notification pops up that you are using the development version of the koka sdk
+
 ## Older Release Notes
 
 * `v2.1.9`, 2021-06-23: initial support for cross-module specialization (by Steven Fontanella).

src/Common/Error.hs

@@ -11,7 +11,7 @@
 -----------------------------------------------------------------------------
 module Common.Error( Error, ErrorMessage(..), errorMsg, ok
                    , catchError, checkError, warningMsg, addWarnings, ignoreWarnings
-                   , ppErrorMessage, errorWarning ) where
+                   , ppErrorMessage, errorWarning, prettyWarnings ) where
 
 import Control.Monad
 import Control.Monad.Fail

src/Common/Range.hs

@@ -14,7 +14,7 @@ module Common.Range
           ( Pos, makePos, minPos, maxPos, posColumn, posLine, posOfs
           , posMove8, posMoves8, posNull
           , Range, showFullRange
-          , makeRange, rangeNull, combineRange, rangeEnd, rangeStart
+          , makeRange, rangeNull, combineRange, rangeEnd, rangeStart, rangeLength
           , Ranged( getRange ), combineRanged
           , combineRangeds, combineRanges, extendRange
           , Source(Source,sourceName, sourceBString), sourceText, sourceFromRange
@@ -275,6 +275,10 @@ rangeStart (Range p1 p2)  = p1
 rangeEnd :: Range -> Pos
 rangeEnd   (Range p1 p2)  = p2
 
+-- | Return the length of a range
+rangeLength :: Range -> Int
+rangeLength (Range p1 p2) = posOfs p2 - posOfs p1
+
 -- | Return the source of a range
 rangeSource :: Range -> Source
 rangeSource = posSource . rangeStart

src/Common/Syntax.hs

@@ -147,7 +147,7 @@ isHandlerNormal _ = False
 
 
 data OperationSort 
-  = OpVal | OpFun | OpExcept | OpControlRaw | OpControl
+  = OpVal | OpFun | OpExcept | OpControlRaw | OpControl | OpControlErr
   deriving (Eq,Ord)
 
 instance Show OperationSort where
@@ -157,6 +157,7 @@ instance Show OperationSort where
                   OpExcept -> "brk"
                   OpControl -> "ctl"
                   OpControlRaw -> "rawctl"
+                  OpControlErr -> ""
 
 readOperationSort :: String -> Maybe OperationSort
 readOperationSort s