Let's stop parser Hell

[Chad J]

On 07/07/2012 07:04 PM, Roman D. Boiko wrote:
> On Saturday, 7 July 2012 at 22:45:01 UTC, Chad J wrote:
>> I see what you mean.
> And I think that I expressed myself badly. Let me rephrase.
>
> When the memory hierarchy is deep, every level would require at least
> one bit position. Or even every base class would require a separate bit.
> (I think that the former + several bits to distinguish among
> hierarchies.) Otherwise it would not be easy to check by a bit-mask.
> Even if the above is incorrect (and that is likely since I didn't try to
> encode that compactly for the real grammar), I think that in general
> that information would only be possible to store in a fairly large
> integral. Especially if we try to generate parser from grammar, and thus
> can't do fine-tuning to pack the information tightly. This overhead
> would be paid per each AST node __instance__. But that is not necessary,
> since we could store information in a lookup table only once per node
> __type__.

Yep. Makes sense.