On 4/22/20 5:21 PM, Sebastiaan Koppe wrote:
On Wednesday, 22 April 2020 at 20:27:12 UTC, Steven Schveighoffer wrote:
Just wanted to throw this out there on a slow day. I wrote this little
utility to generate static lookup tables, because using an AA is too
expensive for something like e.g. looking up database row data by
column name.
It's very crude, but very short and sweet. Hopefully people find a use
for it.
Let me know if you have any requests or find any bugs on github.
https://code.dlang.org/packages/lookuptable
Nice.
For the indexLookup you can also use https://github.com/skoppe/perfect-hash
Hm... thanks for the suggestion. I'm not sure if it fits here, as the
point is to avoid runtime cost and GC allocation, not make lookups
uber-fast.
These are meant to be short-lived things. My main target was e.g.
mysql-native has an "asAA" function which generates an AA with keys
being the column names. This is kind of crappy, because if you do that
for each row, then you are generating and throwing away a LOT of data.
But if you generate the lookup index once per sequence, and you reuse
that, you have much more efficiency, and are only generating one array.
Possibly if I can figure out a good API, you could do it with
malloc/free instead of using GC, but I'm happy with it right now anyway.
-Steve