+testcase {
+ input "if (x) if (y) z else q";
+ output "if:{ident:{{x}} else:{if:{ident:{{y}} then:{ident:{{z}}}} ident:{{q}}}}";
+
+ s = Expr
+ Expr = if:: "if" "(" Expr ")" IfBody /ws
+ | ident:: [a-z]++
+ IfBody = else:: Expr "else" Expr /ws
+ | then:: Expr &~ ((~[])* "else" !Expr /ws)
+ ws = [ ]**
+}