LSP Mk I

docs/language-server.markdown

@@ -0,0 +1,43 @@
+# Unison Language Server
+
+[![asciicast](https://asciinema.org/a/Kwa7NscffA3R8KCHxq1OavRm0.svg)](https://asciinema.org/a/Kwa7NscffA3R8KCHxq1OavRm0)
+
+## Overview
+
+Supported features:
+
+* Show type on hover
+* Inline type and parser error messages
+* NO autocomplete yet, but soon.
+
+Notes:
+
+* The LSP listens for changes from the UCM it's linked to, so name resolution is dependent on your current UCM path.
+
+## Installation and setup
+
+Currently the only supported configuration is to connect to the LSP via a specified port, not all LSP implementations support this configuration.
+
+By default the LSP is hosted at `127.0.0.1:5757`, but you can change the port using `UNISON_LSP_PORT=1234`.
+
+
+### NeoVim
+
+Configuration for [coc-nvim](https://github.com/neoclide/coc.nvim), enter the following in the relevant place of your CocConfig
+
+```
+  "languageserver": {
+    "unison": {
+      "filetypes": ["unison"],
+      "host": "127.0.0.1",
+      "port": 5757
+    }
+  }
+```
+
+Note that you'll need to start UCM _before_ you try connecting to it in your editor or your editor might give up.
+
+### VSCode
+
+VSCode doesn't allow customizing LSP implementations without an extension,
+Hang tight, one will be available soon!

lib/unison-prelude/src/Unison/Debug.hs

@@ -28,6 +28,8 @@ data DebugFlag
   | Migration
   | Sqlite
   | Sync
+  | -- Language server
+    LSP
   | -- | Timing how long things take
     Timing
   deriving (Eq, Ord, Show, Bounded, Enum)
@@ -48,6 +50,7 @@ debugFlags = case (unsafePerformIO (lookupEnv "UNISON_DEBUG")) of
       "MIGRATION" -> pure Migration
       "SQLITE" -> pure Sqlite
       "SYNC" -> pure Sync
+      "LSP" -> pure LSP
       "TIMING" -> pure Timing
       _ -> empty
 {-# NOINLINE debugFlags #-}
@@ -80,6 +83,10 @@ debugSync :: Bool
 debugSync = Sync `Set.member` debugFlags
 {-# NOINLINE debugSync #-}
 
+debugLSP :: Bool
+debugLSP = LSP `Set.member` debugFlags
+{-# NOINLINE debugLSP #-}
+
 debugTiming :: Bool
 debugTiming = Timing `Set.member` debugFlags
 {-# NOINLINE debugTiming #-}
@@ -131,4 +138,5 @@ shouldDebug = \case
   Migration -> debugMigration
   Sqlite -> debugSqlite
   Sync -> debugSync
+  LSP -> debugLSP
   Timing -> debugTiming

parser-typechecker/src/Unison/FileParsers.hs

@@ -18,7 +18,6 @@ import Data.Text (unpack)
 import qualified Unison.ABT as ABT
 import qualified Unison.Blank as Blank
 import qualified Unison.Name as Name
-import Unison.Names (Names)
 import qualified Unison.Names as Names
 import qualified Unison.NamesWithHistory as NamesWithHistory
 import qualified Unison.Parser as Parser
@@ -74,14 +73,14 @@ parseAndSynthesizeFile ::
   ResultT
     (Seq (Note v Ann))
     m
-    (Either Names (UF.TypecheckedUnisonFile v Ann))
+    (Either (UF.UnisonFile v Ann) (UF.TypecheckedUnisonFile v Ann))
 parseAndSynthesizeFile ambient typeLookupf env filePath src = do
   when debug $ traceM "parseAndSynthesizeFile"
   uf <- Result.fromParsing $ Parsers.parseFile filePath (unpack src) env
   let names0 = NamesWithHistory.currentNames (Parser.names env)
   (tm, tdnrMap, typeLookup) <- resolveNames typeLookupf names0 uf
   let (Result notes' r) = synthesizeFile ambient typeLookup tdnrMap uf tm
-  tell notes' $> maybe (Left (UF.toNames uf)) Right r
+  tell notes' $> maybe (Left uf) Right r
 
 type TDNRMap v = Map Typechecker.Name [Typechecker.NamedReference v Ann]
 
@@ -221,7 +220,7 @@ synthesizeFile ambient tl fqnsByShortName uf term = do
         resolve shortv loc replacement t = case t of
           Term.Blank' (Blank.Recorded (Blank.Resolve loc' name))
             | loc' == loc && Var.nameStr shortv == name ->
-                -- loc of replacement already chosen correctly by whatever made the
-                -- Decision
-                pure . pure $ replacement
+              -- loc of replacement already chosen correctly by whatever made the
+              -- Decision
+              pure . pure $ replacement
           _ -> Nothing

parser-typechecker/src/Unison/PrettyPrintEnvDecl.hs

@@ -17,3 +17,10 @@ data PrettyPrintEnvDecl = PrettyPrintEnvDecl
     suffixifiedPPE :: PrettyPrintEnv
   }
   deriving (Show)
+
+instance Semigroup PrettyPrintEnvDecl where
+  PrettyPrintEnvDecl unSuff1 suff1 <> PrettyPrintEnvDecl unSuff2 suff2 =
+    PrettyPrintEnvDecl (unSuff1 <> unSuff2) (suff1 <> suff2)
+
+instance Monoid PrettyPrintEnvDecl where
+  mempty = PrettyPrintEnvDecl mempty mempty