[e-lang] Expansion without HilbertHotel (was Scope oddities in
kpreid at attglobal.net
Sat Mar 11 23:15:43 EST 2006
On Mar 11, 2006, at 21:41, Mark S. Miller wrote:
> Except for the awful Hilbert hotel renaming issue, a Kernel-E
> expression expanded by the E-to-Kernel-E expansion should expand to
The ANTLR parser branch of E-on-CL, which implements Kernel-E
expansion itself, has a name-generation mechanism which does not use
a Hilbert hotel.
Variables generated by expansion are represented not as NounExprs but
as 'TemporaryExpr's, which are effectively non-Selfless ENodes, so a
fresh TemporaryExpr is not the same as any other TemporaryExpr.
After the expansions have been performed, the temporaries are
replaced by NounExprs which are known to not exist in the tree in a
(defun kernelize (node)
"Convert a general E node tree to Kernel-E."
(reify-temporaries (e-macroexpand-all node)))
(I believe the Selfishness of the temporaries is not a problem with
this mechanism, because it is equivalent to the Selfishness of the
What do you think of this mechanism?
Kevin Reid <http://homepage.mac.com/kpreid/>
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