Introspecting object types

[Per Cederberg]

Being tired of all the idiosyncrasies of the typeof() operator, I
tried to make something better:

function typeName(value) {
if (typeof(value) !== "object" && !(value instanceof RegExp)) {
return typeof(value);
} else if (value == null) {
return "null";
} else {
var c = value.constructor || {};
return c.name || c.NAME || "Object";
}
}

Thinking about including this in MochiKit.Base, possibly modifying
typeMatcher() on the go. That would break backward compatibility a
bit, so the question is if it would be worthwhile?

This is how typeName() works right now:

undefined
==> "undefined"
null
==> "null"
false
==> "boolean"
new Boolean(true)
==> "Boolean"
42
==> "number"
new Number(42)
==> "Number" [1]
"test"
==> "string"
new String("")
==> "String" [1]
{ a: 1 }
==> "Object" [2]
[1,2,3]
==> "Array"
new Date()
==> "Date"
/\d+/
==> "RegExp"
new MyClass()
==> "MyClass" [3]

Notes:
[1]: There are two forms of these built-in types, but normally the
"constructor" form is not used much.
[2]: These objects constructor actually point to the Object function,
hence the upper-case initial.
[3]: For this to work, the constructor property must be set and the
constructor function must have either a name or a NAME property.

Cheers,

/Per