then return (True, Var v)
else wildCardPat (idType v)
+argToPat in_scope con_env (Let _ arg) arg_occ
+ = argToPat in_scope con_env arg arg_occ
+ -- Look through let expressions
+ -- e.g. f (let v = rhs in \y -> ...v...)
+ -- Here we can specialise for f (\y -> ...)
+ -- because the rule-matcher will look through the let.
+
argToPat in_scope con_env arg arg_occ
| is_value_lam arg
= return (True, arg)