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Villegas-Gayley (internal function overloads)

This is a way we can assign definitions to built-in functions cleanly. This takes advantage of a two main things, a conditional definition and the power of Block . We’ll use it to overload how MessageName works.

Unprotect@MessageName;
(MessageName[o_,a:Except["usage"]]/;!TrueQ@$recursionBreakingVariable):=
If[
MatchQ[o,object[_Association]],
First[o][a],
Block[{$recursionBreakingVariable=True},
MessageName[o,a]
]
];
Protect@MessageName;

Now we can do fun things with the MessageName operator, ::

object[<|"a"b,"c"d,"e"f|>]::a

(*Out:*)

b

Usually that would have thrown an error:

abject[<|"a"b,"c"d,"e"f|>]::a

(*Out:*)

MessageName[abject[Association["a"b,"c"d,"e"f]],"a"]

And the reason we did this the way we did is because if we assigned some object to a variable, variable::a would give us something meaningless. See:

variable=abject[<|"a"b,"c"d,"e"f|>];

variable::a

(*Out:*)

variable::a

But if it’s an object it will be treated differently:

variable=object[<|"a"b,"c"d,"e"f|>];

variable::a

(*Out:*)

b

And because of the structure of the overload, MessageName still works normally in every other case.