complete arrays in patterns

Author: zth

analysis/src/CompletionBackEnd.ml

@@ -1521,6 +1521,8 @@ let rec extractType ~env ~package (t : Types.type_expr) =
   | Tlink t1 | Tsubst t1 | Tpoly (t1, []) -> extractType ~env ~package t1
   | Tconstr (Path.Pident {name = "option"}, [payloadTypeExpr], _) ->
     Some (Completable.Toption (env, payloadTypeExpr))
+  | Tconstr (Path.Pident {name = "array"}, [payloadTypeExpr], _) ->
+    Some (Tarray (env, payloadTypeExpr))
   | Tconstr (Path.Pident {name = "bool"}, [], _) -> Some (Tbool env)
   | Tconstr (path, _, _) -> (
     match References.digConstructor ~env ~package path with
@@ -1665,6 +1667,12 @@ let completeTypedValue ~env ~envWhereCompletionStarted ~full ~prefix
               ~insertText:(if !Cfg.supportsSnippets then "{$0}" else "{}")
               ~sortText:"a" ~kind:(Value typeExpr) ~env ();
           ])
+      | Some (Tarray (env, typeExpr)) ->
+        [
+          Completion.createWithSnippet ~name:"[]"
+            ~insertText:(if !Cfg.supportsSnippets then "[$0]" else "[]")
+            ~sortText:"a" ~kind:(Value typeExpr) ~env ();
+        ]
       | _ -> []
     in
     (* Include all values and modules in completion if there's a prefix, not otherwise *)
@@ -1796,6 +1804,8 @@ let rec resolveNestedPattern typ ~env ~package ~nested =
         match List.nth_opt constructor.args payloadNum with
         | None -> None
         | Some typ -> typ |> resolveNestedPattern ~env ~package ~nested))
+    | PArray, Some (Tarray (env, typ)) ->
+      typ |> resolveNestedPattern ~env ~package ~nested
     | _ -> None)
 
 let processCompletable ~debug ~full ~scope ~env ~pos ~forHover

analysis/src/CompletionFrontEnd.ml

@@ -510,6 +510,9 @@ let completionWithParser1 ~currentFile ~debug ~offset ~path ~posCursor ~text =
       | Ppat_construct ({txt = Lident prefix}, None) ->
         commitFoundPat ~prefix ()
       | Ppat_variant (prefix, None) -> commitFoundPat ~prefix:("#" ^ prefix) ()
+      | Ppat_array arrayPatterns ->
+        appendNestedPat Completable.PArray;
+        if List.length arrayPatterns = 0 then commitFoundPat ~prefix:"" ()
       | Ppat_tuple patterns -> (
         match patterns |> findPatTupleItemWithCursor ~pos:posBeforeCursor with
         | Some itemNum -> appendNestedPat (Completable.PTupleItem {itemNum})

analysis/src/SharedTypes.ml

@@ -559,6 +559,7 @@ module Completable = struct
     | PRecordBody of {seenFields: string list}
     | PVariantPayload of {constructorName: string; payloadNum: int}
     | PPolyvariantPayload of {constructorName: string; payloadNum: int}
+    | PArray
 
   let patternPathToString p =
     match p with
@@ -571,6 +572,7 @@ module Completable = struct
     | PPolyvariantPayload {constructorName; payloadNum} ->
       "polyvariantPayload::" ^ constructorName ^ "($" ^ string_of_int payloadNum
       ^ ")"
+    | PArray -> "array"
 
   type t =
     | Cdecorator of string  (** e.g. @module *)
@@ -602,6 +604,7 @@ module Completable = struct
     | Tuple of QueryEnv.t * Types.type_expr list * Types.type_expr
     | Toption of QueryEnv.t * Types.type_expr
     | Tbool of QueryEnv.t
+    | Tarray of QueryEnv.t * Types.type_expr
     | Tvariant of {
         env: QueryEnv.t;
         constructors: Constructor.t list;

analysis/tests/src/CompletionPattern.res

@@ -105,3 +105,12 @@ ignore(b)
 
 // switch b { | #three({})}
 //                      ^com
+
+let c: array<bool> = []
+ignore(c)
+
+// switch c { | }
+//             ^com
+
+// switch c { | [] }
+//               ^com

analysis/tests/src/expected/CompletionPattern.res.txt

@@ -390,3 +390,36 @@ Completable: Cpattern Value[b]->polyvariantPayload::three($0), recordBody
     "documentation": null
   }]
 
+Complete src/CompletionPattern.res 111:15
+XXX Not found!
+Completable: Cpattern Value[c]
+[{
+    "label": "[]",
+    "kind": 12,
+    "tags": [],
+    "detail": "bool",
+    "documentation": null,
+    "sortText": "a",
+    "insertText": "[$0]",
+    "insertTextFormat": 2
+  }]
+
+Complete src/CompletionPattern.res 114:17
+looking for: Cpath Value[c] 
+posCursor:[114:17] posNoWhite:[114:16] Found expr:[114:3->114:20]
+posCursor:[114:17] posNoWhite:[114:16] Found pattern:[114:16->114:18]
+Completable: Cpattern Value[c]->array
+[{
+    "label": "true",
+    "kind": 4,
+    "tags": [],
+    "detail": "bool",
+    "documentation": null
+  }, {
+    "label": "false",
+    "kind": 4,
+    "tags": [],
+    "detail": "bool",
+    "documentation": null
+  }]
+