use pretty printer to convert expressions to strings
Now that it is possible to have regular expression constraints on expressions, we need to be able to convert all kinds of expressions to strings.
Reported by: Absoler in github issue #296
Prochaines maintenances programmées: lundi 06/05, lundi 03/06, lundi 01/07
Pour plus d'informations: https://doc-si.inria.fr/display/SU/Gitlab
Now that it is possible to have regular expression constraints on expressions, we need to be able to convert all kinds of expressions to strings.
Reported by: Absoler in github issue #296