[flow][refactor] Pull out string_of_variable_kind function for re-use

Summary:
Pull out `string_of_variable_kind` function for re-use.

Changelog: [internal]

Reviewed By: SamChou19815

Differential Revision:
D67502320

------------------------------------------------------------------------
(from d93582fdb364287bf1bfcf6bcd8b915285ffb6db)

fbshipit-source-id: f5a07275123ef62f13e17804ac188d4e702fc0e7

src/parser/estree_translator.ml

@@ -772,7 +772,7 @@ with type t = Impl.t = struct
       let (loc, _) = id in
       node "MatchIdentifierPattern" loc [("id", identifier id)]
     and match_binding_pattern (loc, { MatchPattern.BindingPattern.kind; id; comments }) =
-      let kind = variable_kind kind in
+      let kind = Flow_ast_utils.string_of_variable_kind kind in
       node ?comments "MatchBindingPattern" loc [("id", identifier id); ("kind", string kind)]
     and match_rest_pattern (loc, { MatchPattern.RestPattern.argument; comments }) =
       node ?comments "MatchRestPattern" loc [("argument", option match_binding_pattern argument)]
@@ -915,7 +915,7 @@ with type t = Impl.t = struct
         [("body", statement_list body)]
     and declare_variable (loc, { Statement.DeclareVariable.id; annot; kind; comments }) =
       let id_loc = Loc.btwn (fst id) (fst annot) in
-      let kind = variable_kind kind in
+      let kind = Flow_ast_utils.string_of_variable_kind kind in
       node
         ?comments
         "DeclareVariable"
@@ -1687,13 +1687,8 @@ with type t = Impl.t = struct
         "TaggedTemplateExpression"
         loc
         [("tag", expression tag); ("quasi", template_literal quasi)]
-    and variable_kind kind =
-      match kind with
-      | Variable.Var -> "var"
-      | Variable.Let -> "let"
-      | Variable.Const -> "const"
     and variable_declaration (loc, { Statement.VariableDeclaration.kind; declarations; comments }) =
-      let kind = variable_kind kind in
+      let kind = Flow_ast_utils.string_of_variable_kind kind in
       node
         ?comments
         "VariableDeclaration"

src/parser/flow_ast_utils.ml

@@ -113,6 +113,11 @@ let rec match_pattern_has_binding =
   | (_, OrPattern { OrPattern.patterns; _ }) -> List.exists match_pattern_has_binding patterns
   | (_, AsPattern _) -> true
 
+let string_of_variable_kind = function
+  | Variable.Var -> "var"
+  | Variable.Let -> "let"
+  | Variable.Const -> "const"
+
 let partition_directives statements =
   let open Statement in
   let rec helper directives = function

src/parser/flow_ast_utils.mli

@@ -24,6 +24,8 @@ val pattern_has_binding : ('m, 't) Flow_ast.Pattern.t -> bool
 
 val match_pattern_has_binding : ('m, 't) Flow_ast.MatchPattern.t -> bool
 
+val string_of_variable_kind : Flow_ast.Variable.kind -> string
+
 val partition_directives :
   (Loc.t, Loc.t) Flow_ast.Statement.t list ->
   (Loc.t, Loc.t) Flow_ast.Statement.t list * (Loc.t, Loc.t) Flow_ast.Statement.t list

src/parser_utils/output/js_layout_generator.ml

@@ -1735,11 +1735,7 @@ and template_literal ~opts { Ast.Expression.TemplateLiteral.quasis; expressions;
   in
   fuse [Atom "`"; fuse (List.mapi template_element quasis); Atom "`"]
 
-and variable_kind kind =
-  match kind with
-  | Ast.Variable.Var -> Atom "var"
-  | Ast.Variable.Let -> Atom "let"
-  | Ast.Variable.Const -> Atom "const"
+and variable_kind kind = Atom (Flow_ast_utils.string_of_variable_kind kind)
 
 and variable_declaration
     ?(ctxt = normal_context)