prechelt-phone-number-encoding VS libphonenumber

You're looking at the non-optimized version. If you read the blog post you would've seen your suggestions had already been implemented.

> it’s using Unicode-aware string stuff

Rust uses UTF-8 internally for Strings, so it's very efficient to parse a file into a String, then using slices to go through it... this is probably the best you can get as parsing ASCII input as UTF-8 is very efficient (the 0-bit is always zero in ASCII, the unicode decoder only needs to check that's the case for every byte, so it's not some kind of complicated computation it's doing to decode)...

If you use bytes for everything, you will make the whole code much harder to follow and it still won't run faster.

Check for yourself: https://github.com/renatoathaydes/prechelt-phone-number-enco...

This is a pretty introductory CL article, mostly a commentary on Norvig's solution to the problem. Still, I learned about the #. readmacro from it. The conclusion: "[The Lisp implementation] was the fastest implementation for all input sizes except the largest one, where it performed just slightly worse than my best Java implementation." GH repo at https://github.com/renatoathaydes/prechelt-phone-number-enco.... Sounds like he was mostly measuring the performance of the SBCL bignum implementation.

Here are the commits I've made so far. If anyone wants to help write the most efficient possible Lisp implementation, please send suggestions here!

OMG you're right... I'm the author, and the reason it was allocating in my original code was that I was calling the operators on a reference to n. See https://github.com/renatoathaydes/prechelt-phone-number-encoding/commit/6683dc10cc4fb380abead632b87d94e8937f8377

This commit show how to improve that: https://github.com/renatoathaydes/prechelt-phone-number-encoding/commit/561a7307b5574bd6fd7b8cc638abf6f29884b6ca

See https://github.com/renatoathaydes/prechelt-phone-number-encoding/issues/6

I get the need to want to obsessively optimize the code. There's nothing more fun than to optimize something simple, artificial, and narrowly-defined. But y'all need to take a deep breath, step back, and realize that one blog post isn't going to suddenly define the language (nor should it personally define you).

source: https://github.com/renatoathaydes/prechelt-phone-number-enco...

libphonenumber can format in many ways, you can find the national patterns in the metadata files https://github.com/google/libphonenumber/blob/master/resources/PhoneNumberMetadata.xml

For instance, the XML file https://github.com/google/libphonenumber/blob/master/resources/PhoneNumberMetadata.xml contains Phone number metadata with possible lengths, broken down by countries.

From falsehoods developers believe about phone numbers :

This makes the assumption that Twitter blocked it due to SMS fraud. While that's a plausible theory an equally plausible theory is that they were worried about account hijacking and security (and allowed twitter blue subscribers to continue to use it on a you can pay me to be stupid context) which seems equally plausible.

I take issue with a lot of the assumptions in the article but this is funny:

> Identify and block premium rate phone numbers, using libphonenumber. Whilst this seems promising, I don’t know how reliable the data and how effective this approach is.

here's this purpose-built and well maintained* library from google which does exactly what I want but i'm not even going to consider it.

* the actual number database has been updated 5x so far this year: https://github.com/google/libphonenumber/commits/master/meta...

Yeah, but you can probably use https://github.com/google/libphonenumber for that.

You can find the Github repo and documentation for the library here.