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Whilst argument pattern matching works against a single MTools class name, there is no intrinsic consideration of inheritance. Consider this setup with MClassB extends MClassA:
NEW: The Webel recipe for pseudo classes with adapted Abstract Data Types (ADTs) handles design-by-contract fine:
BeginPackage["Demo`", {"MTools`"}]
$ContextAliases["M`"] = "MTools`Core`MPlusPlus`";
MClassA = M`NewClass[{"Fields"->{"name"}}]
MClassB = M`NewClass[{"Parents"->{MClassA}}]
newB::usage = "newRefR32[name]";
Begin["`Private`"]
newB[name_] := M`New[MClassB]["name"->name];
End[]
EndPackage[]
This works as expected (matches against a specific class):
i: b1 = newB["b1"];
i: fTestB[b_MClassB] := M`o.name;
i: fTestB[b1]
o: b1
But matching against the parent (base) class does not work:
i: fTestA[b_MClassA] := M`o.name;
i: fTestA[b1]
o: fTestA[MClassB[object$123435]]
The Webel MAll MTools extension and All` package provide additional support for more convenient contract tests for use with PatternTest (? queries), as shown in this slide:
But it's not so elegant (it would be nicer to have contract matching built-in via a fully vendor supported OO mechanism). Visit also:
NEW: The Webel recipe for pseudo classes with adapted Abstract Data Types (ADTs) handles design-by-contract fine: