Add ?opt props syntax (with punning)

Author: andreypopp

mlx/jsx_helper.ml

@@ -62,12 +62,16 @@ let make_jsx_element ~raise ~loc:_ ~tag ~end_tag ~props ~children () =
         mkexp ~loc (Pexp_ident { loc = make_loc loc; txt })
   in
   let props =
+    let prop_exp ~loc name =
+      let id = mkloc (Lident name) (make_loc loc) in
+      mkexp ~loc (Pexp_ident id)
+    in
     List.map
       (function
-        | loc, `Prop_punned name ->
-            let id = mkloc (Lident name) (make_loc loc) in
-            Labelled name, mkexp ~loc (Pexp_ident id)
-        | _loc, `Prop (name, expr) -> Labelled name, expr)
+        | loc, `Prop_punned name -> Labelled name, prop_exp ~loc name
+        | loc, `Prop_opt_punned name -> Optional name, prop_exp ~loc name
+        | _loc, `Prop (name, expr) -> Labelled name, expr
+        | _loc, `Prop_opt (name, expr) -> Optional name, expr)
       props
   in
   let unit =

mlx/parser.ml

@@ -2523,7 +2523,9 @@ jsx_element:
 ;
 jsx_prop:
     name=LIDENT { $loc(name), `Prop_punned name }
+  | QUESTION name=LIDENT { $loc(name), `Prop_opt_punned name }
   | name=LIDENT EQUAL expr=simple_expr { $loc(name), `Prop (name, expr) }
+  | QUESTION name=LIDENT EQUAL expr=simple_expr { $loc(name), `Prop_opt (name, expr) }
 ;
 labeled_simple_expr:
     simple_expr %prec below_HASH

mlx/parser.mly

@@ -390,7 +390,10 @@ module MenhirInterpreter : sig
     | N_reversed_llist_simple_expr_ : (Parsetree.expression list) nonterminal
     | N_reversed_llist_preceded_CONSTRAINT_constrain__ : ((Parsetree.core_type * Parsetree.core_type * Warnings.loc) list) nonterminal
     | N_reversed_llist_jsx_prop_ : (((Lexing.position * Lexing.position) *
-   [ `Prop of string * Parsetree.expression | `Prop_punned of string ])
+   [ `Prop of string * Parsetree.expression
+   | `Prop_opt of string * Parsetree.expression
+   | `Prop_opt_punned of string
+   | `Prop_punned of string ])
   list) nonterminal
     | N_reversed_bar_llist_extension_constructor_declaration_ : (Parsetree.extension_constructor list) nonterminal
     | N_reversed_bar_llist_extension_constructor_ : (Parsetree.extension_constructor list) nonterminal
@@ -500,7 +503,10 @@ module MenhirInterpreter : sig
     | N_label_declaration_semi : (Parsetree.label_declaration) nonterminal
     | N_label_declaration : (Parsetree.label_declaration) nonterminal
     | N_jsx_prop : ((Lexing.position * Lexing.position) *
-  [ `Prop of string * Parsetree.expression | `Prop_punned of string ]) nonterminal
+  [ `Prop of string * Parsetree.expression
+  | `Prop_opt of string * Parsetree.expression
+  | `Prop_opt_punned of string
+  | `Prop_punned of string ]) nonterminal
     | N_jsx_longident_JSX_UIDENT_E_JSX_LIDENT_E_ : ([> `Module | `Value ] * (Lexing.position * Lexing.position) * Longident.t) nonterminal
     | N_jsx_longident_JSX_UIDENT_JSX_LIDENT_ : ([ `Module | `Value ] * (Lexing.position * Lexing.position) * Longident.t) nonterminal
     | N_jsx_element : (Parsetree.expression_desc) nonterminal

ocamlmerlin_mlx/preprocess/parser_raw.cmly

@@ -2697,7 +2697,9 @@ jsx_element:
 ;
 jsx_prop:
     name=LIDENT { $loc(name), `Prop_punned name }
+  | QUESTION name=LIDENT { $loc(name), `Prop_opt_punned name }
   | name=LIDENT EQUAL expr=simple_expr { $loc(name), `Prop (name, expr) }
+  | QUESTION name=LIDENT EQUAL expr=simple_expr { $loc(name), `Prop_opt (name, expr) }
 ;
 labeled_simple_expr:
     simple_expr %prec below_HASH

ocamlmerlin_mlx/preprocess/parser_raw.ml

@@ -17,6 +17,12 @@
   MERLIN
   let _ = div () ~children:[] ~attr ~with_value:1 [@JSX]
 
+  $ echo 'let _ = <div ?opt ?opt_value=some />' | ./mlx
+  BATCH
+  let _ = div () ~children:[] ?opt ?opt_value:some [@JSX]
+  MERLIN
+  let _ = div () ~children:[] ?opt ?opt_value:some [@JSX]
+
   $ echo 'let _ = <Hello attr with_value=1 />' | ./mlx
   BATCH
   let _ = Hello.createElement () ~children:[] ~attr ~with_value:1 [@JSX]