[plt-scheme] Re: polymorphism of primitive types

Matthias Felleisen wrote:
> Roughly speaking, shared
> is for data what letrec is for functions (which shows that in Scheme, we
> only create an illusion that lambda is first-class. But so much for
> heresy.)

I don't understand what you're saying; could you explain?

I never thought lambda was first-class.  Procedures are first class, and
lambda is a constructor for procedures, as is letrec.  Where's the heresy?

David