Improve error msg in tcPolyExpr; Simon pls merge into release
newDicts SignatureOrigin sig_theta `thenNF_Tc` \ (sig_dicts, dict_ids) ->
-- ToDo: better origin
tcSimplifyAndCheck
newDicts SignatureOrigin sig_theta `thenNF_Tc` \ (sig_dicts, dict_ids) ->
-- ToDo: better origin
tcSimplifyAndCheck
+ (text "the type signature of an expression")
(mkVarSet zonked_sig_tyvars)
sig_dicts lie_arg `thenTc` \ (free_insts, inst_binds) ->
(mkVarSet zonked_sig_tyvars)
sig_dicts lie_arg `thenTc` \ (free_insts, inst_binds) ->