WIP: surface syntax for parentheticals

dfinity · Jul 10, 2024 · d4811e2 · d4811e2
1 parent 7feb398
commit d4811e2
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diff --git a/doc/md/examples/grammar.txt b/doc/md/examples/grammar.txt
@@ -214,6 +214,7 @@
     'break' <id> <exp_nullary>?
     'continue' <id>
     'debug' <exp_nest>
+    '(' <exp_post>? 'with' <list(<exp_field>, ';')> ')' <exp_nest>
     'if' <exp_nullary> <exp_nest>
     'if' <exp_nullary> <exp_nest> 'else' <exp_nest>
     'try' <exp_nest> <catch>

diff --git a/src/mo_frontend/parser.mly b/src/mo_frontend/parser.mly
@@ -703,6 +703,12 @@ exp_un(B) :
       BreakE(x', TupE([]) @? no_region) @? at $sloc }
   | DEBUG e=exp_nest
     { DebugE(e) @? at $sloc }
+  | LPAR base=exp_post(ob)? WITH fs=seplist(exp_field, semicolon) RPAR e=exp_nest (* parentheticals to qualify message sends *)
+    { match e.it with
+      | CallE _
+      | AsyncE (Type.Fut, _, _) -> e
+      | _ -> { e with it = ObjE(Option.to_list base, fs) }
+    }
   | IF b=exp_nullary(ob) e1=exp_nest %prec IF_NO_ELSE
     { IfE(b, e1, TupE([]) @? at $sloc) @? at $sloc }
   | IF b=exp_nullary(ob) e1=exp_nest ELSE e2=exp_nest