Trying to implement FPOSITION with LAMBDA-MACROs and SUBSTs

[Earl A. Killian <EAK at MIT-MC>]

I don't want SUBSTs in Common Lisp, I want the real thing, ie.
inline functions.  They can be implemented easily in any
implementation by replacing the function name with its lambda
expression (this isn't quite true, because of free variables, but
that's not really that hard to deal with in a compiler).  Now the
issue is simply efficiency.  Since Common Lisp has routinely
chosen cleanliness when efficiency can be dealt with by the
compiler (as it is in the S-1 compiler), then I see no reason to
have ugly SUBSTs.