proper tail calls

Jeff Dyer jodyer at
Mon Jan 21 13:11:15 PST 2008

On 1/21/08 12:35 PM, Brendan Eich wrote:

> So the axes of disagreement seem to me to be:

We need to agree on the primary purpose of proper tail calls. I say it is
portability of code, and that all other concerns do not have enough weight
to influence this proposal.

> 1. explicit vs. implicit,

Since PTC is about portability of code then what matters most is that
implementations agree on what a tail call is. If the spec is unambiguous
about what a tail call is, then implementations will have little trouble
agreeing. Anyway, an explicit marking won't help.

> 2. whether to have a tail annotation if implicit,

Ditto. It won't aid in ensuring portability of code.

> 3. statement vs. expression if explicit, and


> 4. whether explicit is required for debug-ability.

PTC should not be for improving debug-ability.


More information about the Es4-discuss mailing list