fix pattern matching of dict

Author: tsnobip

jscomp/syntax/src/res_grammar.ml

@@ -131,7 +131,7 @@ let is_signature_item_start = function
 
 let is_atomic_pattern_start = function
   | Token.Int _ | String _ | Codepoint _ | Backtick | Lparen | Lbracket | Lbrace
-  | Underscore | Lident _ | Uident _ | List | Exception | Percent ->
+  | Underscore | Lident _ | Uident _ | List | Dict | Exception | Percent ->
     true
   | _ -> false
 
@@ -170,8 +170,8 @@ let is_structure_item_start = function
 
 let is_pattern_start = function
   | Token.Int _ | Float _ | String _ | Codepoint _ | Backtick | True | False
-  | Minus | Plus | Lparen | Lbracket | Lbrace | List | Underscore | Lident _
-  | Uident _ | Hash | Exception | Percent | Module | At ->
+  | Minus | Plus | Lparen | Lbracket | Lbrace | List | Dict | Underscore
+  | Lident _ | Uident _ | Hash | Exception | Percent | Module | At ->
     true
   | _ -> false
 

jscomp/syntax/tests/parsing/grammar/pattern/expected/dict.res.txt

@@ -1,36 +1,41 @@
-
-  Syntax error!
-  tests/parsing/grammar/pattern/dict.res:28:12-16
-
-  26 │ let decodeUser = (json: json): option<user> => {
-  27 │   switch json {
-  28 │   | Object(dict{
-  29 │     "name": String(name), 
-  30 │     "age": ageJson
-
-  Did you forget a `)` here?
-
-
-  Syntax error!
-  tests/parsing/grammar/pattern/dict.res:31:6
-
-  29 ┆ "name": String(name), 
-  30 ┆ "age": ageJson
-  31 ┆ }) =>
-  32 ┆ Some({
-  33 ┆   name,
-
-  I'm not sure what to parse here when looking at ")".
-
-
-  Syntax error!
-  tests/parsing/grammar/pattern/dict.res:41:3
-
-  39 ┆     },
-  40 ┆   })
-  41 ┆ | _ =>
-  42 ┆   Js.log("Not an object.")
-  43 ┆   None
-
-  I'm not sure what to parse here when looking at "|".
-
+let someDict = Primitive_dict.make [|("one", {js|one|js})|]
+let (({ one = ((one)[@res.optional ]);_})[@res.dictPattern ]) = someDict
+let foo =
+  ((Function$
+      (fun () ->
+         match someDict with
+         | (({ one = {js|one|js};_})[@res.dictPattern ]) ->
+             Js.log {js|one|js}
+         | _ -> Js.log {js|not one|js}))
+  [@res.arity 1])
+type json =
+  | Boolean of bool 
+  | Null [@as null]
+  | String of string 
+  | Number of float 
+  | Object of json dict 
+  | Array of t array [@@unboxed ]
+type nonrec user = {
+  name: string ;
+  age: float [@res.optional ]}
+let decodeUser =
+  ((Function$
+      (fun (json : json) ->
+         (((match json with
+            | Object
+                (({ name = String name; age = ageJson;_})[@res.dictPattern ])
+                ->
+                Some
+                  {
+                    name;
+                    age =
+                      (((match ageJson with
+                         | Number age -> Some age
+                         | _ -> None))[@res.optional ])
+                  }
+            | _ -> (Js.log {js|Not an object.|js}; None))
+         [@res.braces ]) : user option)))
+  [@res.arity 1])
+;;Js.log
+    (decodeUser
+       (jsonParse (({js|{"name": "John", "age": 30}|js})[@res.template ])))