Implement completions for cabal files

Includes:
* completions for keywords, sensitive to stanzas
* value completions for constant values, files, directories and exposed modules
* completion of snippets for different stanzas and the required basic fields

ghcide/src/Development/IDE/Plugin/Completions.hs

@@ -45,7 +45,6 @@ import qualified Language.LSP.Protocol.Lens               as L
 import           Language.LSP.Protocol.Message
 import           Language.LSP.Protocol.Types
 import qualified Language.LSP.Server                      as LSP
-import qualified Language.LSP.VFS                         as VFS
 import           Numeric.Natural
 import           Text.Fuzzy.Parallel                      (Scored (..))
 

ghcide/src/Text/Fuzzy/Parallel.hs

@@ -1,9 +1,9 @@
 -- | Parallel versions of 'filter' and 'simpleFilter'
 
 module Text.Fuzzy.Parallel
-(   filter,
-    simpleFilter,
-    match,
+(   filter, filter',
+    simpleFilter, simpleFilter',
+    match, defChunkSize, defMaxResults,
     Scored(..)
 ) where
 
@@ -29,7 +29,6 @@ data Scored a = Scored {score :: !Int, original:: !a}
 -- Just 5
 --
 {-# INLINABLE match #-}
-
 match :: T.Text    -- ^ Pattern in lowercase except for first character
       -> T.Text    -- ^ The text to search in.
       -> Maybe Int -- ^ The score
@@ -70,22 +69,13 @@ match (T.Text pArr pOff pLen) (T.Text sArr sOff sLen) = go 0 1 pOff sOff
 
     toLowerAscii w = if (w - 65) < 26 then w .|. 0x20 else w
 
--- | The function to filter a list of values by fuzzy search on the text extracted from them.
-filter :: Int           -- ^ Chunk size. 1000 works well.
-       -> Int           -- ^ Max. number of results wanted
-       -> T.Text        -- ^ Pattern.
-       -> [t]           -- ^ The list of values containing the text to search in.
-       -> (t -> T.Text) -- ^ The function to extract the text from the container.
-       -> [Scored t]    -- ^ The list of results, sorted, highest score first.
-filter chunkSize maxRes pattern ts extract = partialSortByAscScore maxRes perfectScore (concat vss)
-  where
-      -- Preserve case for the first character, make all others lowercase
-      pattern' = case T.uncons pattern of
-        Just (c, rest) -> T.cons c (T.toLower rest)
-        _              -> pattern
-      vss = map (mapMaybe (\t -> flip Scored t <$> match pattern' (extract t))) (chunkList chunkSize ts)
-        `using` parList (evalList rseq)
-      perfectScore = fromMaybe (error $ T.unpack pattern) $ match pattern' pattern'
+-- | Sensible default value for chunk size to use when calling simple filter.
+defChunkSize :: Int
+defChunkSize = 1000
+
+-- | Sensible default value for the number of max results to use when calling simple filter.
+defMaxResults :: Int
+defMaxResults = 10
 
 -- | Return all elements of the list that have a fuzzy
 -- match against the pattern. Runs with default settings where
@@ -102,6 +92,52 @@ simpleFilter :: Int      -- ^ Chunk size. 1000 works well.
 simpleFilter chunk maxRes pattern xs =
   filter chunk maxRes pattern xs id
 
+
+-- | The function to filter a list of values by fuzzy search on the text extracted from them,
+-- using a custom matching function which determines how close words are.
+filter' :: Int           -- ^ Chunk size. 1000 works well.
+       -> Int           -- ^ Max. number of results wanted
+       -> T.Text        -- ^ Pattern.
+       -> [t]           -- ^ The list of values containing the text to search in.
+       -> (t -> T.Text) -- ^ The function to extract the text from the container.
+       -> (T.Text -> T.Text -> Maybe Int)
+       -- ^ Custom scoring function to use for calculating how close words are
+       -- When the function returns Nothing, this means the values are incomparable.
+       -> [Scored t]    -- ^ The list of results, sorted, highest score first.
+filter' chunkSize maxRes pattern ts extract match' = partialSortByAscScore maxRes perfectScore (concat vss)
+  where
+      -- Preserve case for the first character, make all others lowercase
+      pattern' = case T.uncons pattern of
+        Just (c, rest) -> T.cons c (T.toLower rest)
+        _              -> pattern
+      vss = map (mapMaybe (\t -> flip Scored t <$> match' pattern' (extract t))) (chunkList chunkSize ts)
+        `using` parList (evalList rseq)
+      perfectScore = fromMaybe (error $ T.unpack pattern) $ match' pattern' pattern'
+
+-- | The function to filter a list of values by fuzzy search on the text extracted from them,
+-- using a custom matching function which determines how close words are.
+filter :: Int           -- ^ Chunk size. 1000 works well.
+       -> Int           -- ^ Max. number of results wanted
+       -> T.Text        -- ^ Pattern.
+       -> [t]           -- ^ The list of values containing the text to search in.
+       -> (t -> T.Text) -- ^ The function to extract the text from the container.
+       -> [Scored t]    -- ^ The list of results, sorted, highest score first.
+filter chunkSize maxRes pattern ts extract =
+  filter' chunkSize maxRes pattern ts extract match
+
+-- | Return all elements of the list that have a fuzzy match against the pattern,
+-- the closeness of the match is determined using the custom scoring match function that is passed.
+-- Runs with default settings where nothing is added around the matches, as case insensitive.
+{-# INLINABLE simpleFilter' #-}
+simpleFilter' :: Int      -- ^ Chunk size. 1000 works well.
+             -> Int      -- ^ Max. number of results wanted
+             -> T.Text   -- ^ Pattern to look for.
+             -> [T.Text] -- ^ List of texts to check.
+             -> (T.Text -> T.Text -> Maybe Int)
+             -- ^ Custom scoring function to use for calculating how close words are
+             -> [Scored T.Text] -- ^ The ones that match.
+simpleFilter' chunk maxRes pattern xs match' =
+  filter' chunk maxRes pattern xs id match'
 --------------------------------------------------------------------------------
 
 chunkList :: Int -> [a] -> [[a]]

plugins/hls-cabal-plugin/hls-cabal-plugin.cabal

@@ -27,36 +27,39 @@ library
   exposed-modules:
     Ide.Plugin.Cabal
     Ide.Plugin.Cabal.Diagnostics
+    Ide.Plugin.Cabal.Completion.Completer.FilePath
+    Ide.Plugin.Cabal.Completion.Completer.Module
+    Ide.Plugin.Cabal.Completion.Completer.Simple
+    Ide.Plugin.Cabal.Completion.Completer.Snippet
+    Ide.Plugin.Cabal.Completion.Completer.Types
+    Ide.Plugin.Cabal.Completion.Completions
+    Ide.Plugin.Cabal.Completion.Data
+    Ide.Plugin.Cabal.Completion.Types
     Ide.Plugin.Cabal.LicenseSuggest
     Ide.Plugin.Cabal.Parse
 
+
   build-depends:
     , base                  >=4.12     && <5
     , bytestring
-    -- Ideally, we only want to support a single Cabal version, supporting
-    -- older versions is completely pointless since Cabal is backwards compatible,
-    -- the latest Cabal version can parse all versions of the Cabal file format.
-    --
-    -- However, stack is making this difficult, if we change the version of Cabal,
-    -- we essentially need to make sure all other packages in the snapshot have their
-    -- Cabal dependency version relaxed.
-    -- Most packages have a Hackage revision, but stack won't pick these up (for sensible reasons)
-    -- automatically, forcing us to manually update the packages revision id.
-    -- This is a lot of work for almost zero benefit, so we just allow more versions here
-    -- and we eventually completely drop support for building HLS with stack.
-    , Cabal                 ^>=3.2 || ^>=3.4 || ^>=3.6 || ^>= 3.8 || ^>= 3.10
+    , Cabal-syntax          >= 3.7
+    , containers
     , deepseq
     , directory
+    , filepath
     , extra                 >=1.7.4
     , ghcide                == 2.1.0.0
     , hashable
     , hls-plugin-api        == 2.1.0.0
     , hls-graph             == 2.1.0.0
+    , lens
     , lsp                   ^>=2.0.0.0
     , lsp-types             ^>=2.0.0.1
     , regex-tdfa            ^>=1.3.1
     , stm
     , text
+    , text-rope
+    , transformers
     , unordered-containers  >=0.2.10.0
     , containers
   hs-source-dirs:   src
@@ -68,15 +71,24 @@ test-suite tests
   type:             exitcode-stdio-1.0
   hs-source-dirs:   test
   main-is:          Main.hs
+  other-modules:
+    Completer
+    Context
+    Utils
   build-depends:
     , base
     , bytestring
+    , Cabal-syntax          >= 3.7
+    , directory
     , filepath
     , ghcide
     , hls-cabal-plugin
     , hls-test-utils    == 2.1.0.0
     , lens
+    , lsp
     , lsp-types
     , tasty-hunit
     , text
+    , text-rope
+    , transformers
     , row-types