model: add `MClass::signature_to_s` to use in messages.

Signed-off-by: Jean Privat <jean@pryen.org>

diff --git a/src/model/model.nit b/src/model/model.nit
index 62c3db4..cd1e570 100644 (file)
--- a/src/model/model.nit
+++ b/src/model/model.nit
@@ -380,6 +380,29 @@ class MClass
        # is empty if the class is not generic
        var mparameters = new Array[MParameterType]
 
+       # A string version of the signature a generic class.
+       #
+       # eg. `Map[K: nullable Object, V: nullable Object]`
+       #
+       # If the class in non generic the name is just given.
+       #
+       # eg. `Object`
+       fun signature_to_s: String
+       do
+               if arity == 0 then return name
+               var res = new FlatBuffer
+               res.append name
+               res.append "["
+               for i in [0..arity[ do
+                       if i > 0 then res.append ", "
+                       res.append mparameters[i].name
+                       res.append ": "
+                       res.append intro.bound_mtype.arguments[i].to_s
+               end
+               res.append "]"
+               return res.to_s
+       end
+
        # Initialize `mparameters` from their names.
        protected fun setup_parameter_names(parameter_names: nullable Array[String]) is
                autoinit