more advanced completion for arrays

Author: zth

analysis/src/CompletionFrontEnd.ml

@@ -39,16 +39,29 @@ let rec traverseExpr (exp : Parsetree.expression) ~exprPath ~pos
   | Pexp_construct ({txt = Lident "()"}, _) -> someIfHasCursor ("", exprPath)
   | Pexp_construct ({txt = Lident txt}, None) -> someIfHasCursor (txt, exprPath)
   | Pexp_variant (label, None) -> someIfHasCursor ("#" ^ label, exprPath)
-  | Pexp_array arrayPatterns ->
+  | Pexp_array arrayPatterns -> (
     let nextExprPath = [Completable.EArray] @ exprPath in
+    (* No fields but still has cursor = empty completion *)
     if List.length arrayPatterns = 0 && locHasCursor exp.pexp_loc then
       Some ("", nextExprPath)
     else
-      arrayPatterns
-      |> List.find_map (fun e ->
-             e
-             |> traverseExpr ~exprPath:nextExprPath
-                  ~firstCharBeforeCursorNoWhite ~pos)
+      let arrayItemWithCursor =
+        arrayPatterns
+        |> List.find_map (fun e ->
+               e
+               |> traverseExpr ~exprPath:nextExprPath
+                    ~firstCharBeforeCursorNoWhite ~pos)
+      in
+
+      match (arrayItemWithCursor, locHasCursor exp.pexp_loc) with
+      | Some arrayItemWithCursor, _ -> Some arrayItemWithCursor
+      | None, true when firstCharBeforeCursorNoWhite = Some ',' ->
+        (* No item had the cursor, but the entire expr still has the cursor (so
+           the cursor is in the array somewhere), and the first char before the
+           cursor is a comma = interpret as compleing for a new value (example:
+           `[None, <com>, None]`) *)
+        Some ("", nextExprPath)
+      | _ -> None)
   | Pexp_tuple tupleItems when locHasCursor exp.pexp_loc ->
     tupleItems
     |> traverseExprTupleItems ~firstCharBeforeCursorNoWhite ~pos

analysis/tests/src/CompletionExpressions.res

@@ -62,3 +62,22 @@ let fnTakingRecord = (r: someRecord) => {
 
 // let _ = fnTakingRecord({age: 123, polyvariant: #three({}, t) })
 //                                                            ^com
+
+let fnTakingArray = (arr: array<option<bool>>) => {
+  ignore(arr)
+}
+
+// let _ = fnTakingArray()
+//                       ^com
+
+// let _ = fnTakingArray([])
+//                        ^com
+
+// let _ = fnTakingArray([Some()])
+//                             ^com
+
+// let _ = fnTakingArray([None, ])
+//                             ^com
+
+// let _ = fnTakingArray([None, , None])
+//                             ^com

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

@@ -282,3 +282,96 @@ Completable: Cargument Value[fnTakingRecord]($0=t)->recordField(polyvariant), po
     "documentation": null
   }]
 
+Complete src/CompletionExpressions.res 69:25
+posCursor:[69:25] posNoWhite:[69:24] Found expr:[69:11->69:26]
+Pexp_apply ...[69:11->69:24] (...[69:25->69:26])
+Completable: Cargument Value[fnTakingArray]($0)
+[{
+    "label": "[]",
+    "kind": 12,
+    "tags": [],
+    "detail": "option<bool>",
+    "documentation": null,
+    "sortText": "a",
+    "insertText": "[$0]",
+    "insertTextFormat": 2
+  }]
+
+Complete src/CompletionExpressions.res 72:26
+posCursor:[72:26] posNoWhite:[72:25] Found expr:[72:11->72:28]
+Pexp_apply ...[72:11->72:24] (...[72:25->72:27])
+Completable: Cargument Value[fnTakingArray]($0)->array
+[{
+    "label": "None",
+    "kind": 4,
+    "tags": [],
+    "detail": "bool",
+    "documentation": null
+  }, {
+    "label": "Some(_)",
+    "kind": 4,
+    "tags": [],
+    "detail": "bool",
+    "documentation": null,
+    "insertText": "Some(${1:_})",
+    "insertTextFormat": 2
+  }]
+
+Complete src/CompletionExpressions.res 75:31
+posCursor:[75:31] posNoWhite:[75:30] Found expr:[75:11->75:34]
+Pexp_apply ...[75:11->75:24] (...[75:25->75:33])
+Completable: Cargument Value[fnTakingArray]($0)->array, variantPayload::Some($0)
+[{
+    "label": "true",
+    "kind": 4,
+    "tags": [],
+    "detail": "bool",
+    "documentation": null
+  }, {
+    "label": "false",
+    "kind": 4,
+    "tags": [],
+    "detail": "bool",
+    "documentation": null
+  }]
+
+Complete src/CompletionExpressions.res 78:31
+posCursor:[78:31] posNoWhite:[78:30] Found expr:[78:11->78:34]
+Pexp_apply ...[78:11->78:24] (...[78:25->78:33])
+Completable: Cargument Value[fnTakingArray]($0)->array
+[{
+    "label": "None",
+    "kind": 4,
+    "tags": [],
+    "detail": "bool",
+    "documentation": null
+  }, {
+    "label": "Some(_)",
+    "kind": 4,
+    "tags": [],
+    "detail": "bool",
+    "documentation": null,
+    "insertText": "Some(${1:_})",
+    "insertTextFormat": 2
+  }]
+
+Complete src/CompletionExpressions.res 81:31
+posCursor:[81:31] posNoWhite:[81:30] Found expr:[81:11->81:40]
+Pexp_apply ...[81:11->81:24] (...[81:25->81:39])
+Completable: Cargument Value[fnTakingArray]($0)->array
+[{
+    "label": "None",
+    "kind": 4,
+    "tags": [],
+    "detail": "bool",
+    "documentation": null
+  }, {
+    "label": "Some(_)",
+    "kind": 4,
+    "tags": [],
+    "detail": "bool",
+    "documentation": null,
+    "insertText": "Some(${1:_})",
+    "insertTextFormat": 2
+  }]
+