LFE: Lisp Flavored Erlang • Hacker News Board

Re: LFE: Lisp Flavored Erlang

#31

Post by kazinator » Mon, Aug 17, 2020, 4:17 PM UTC

hackingthenews wrote: post #13

smabie wrote: post #10

Earlier quoted context omitted.

Lisp has two big ideas. The first big idea is that a regular syntax allows the trivial implementation of macros. Just have a separate compilation where the AST is passed in as a list to different macros and then compile the result. The second idea (not shared by the some Lisps like Scheme) is that of a system image which is modified in real time. This allows on the fly debugging, adding of new features, etc with no d…

Thanks! I haven't really experienced the image feature, as I used Scheme. It doesn't sound like it would be consequential to how I program, but that might just be my ignorance of it. My experience with the macro stuff is that they enable in-house implementation of language features like lazy evaluation (not possible in other languages without a lot of extra code), which we implemented during the course. But implement…

I had many epiphanies as a CS student in all sorts of CS areas. It was because I was always taking things out of their educational context, and finding applications in programming, or at least seeing what the "big deal" is.

E.g. learning about red-black trees inspired me to write a decent C implementation of them, as something I could use. That ended up used in production all over the place, like in the ext2fsck program.

Undoubtedly, some of my classmates likely also had the reaction "when would I, in everyday programming, be rotating some nodes to balance a tree ..."

Re: LFE: Lisp Flavored Erlang

#32

Post by mercer » Mon, Aug 17, 2020, 6:05 PM UTC

whynotwhynot wrote: post #30

mercer wrote: post #28

Earlier quoted context omitted.

My 'A-ha' moment with Elixir was exactly your example. Both me and a friend were building an app that ingests cryptocurrency data and stores it in a database for later analysis. The important part was that we wanted data at regular intervals. I'm not much into all this but this is what was asked of us. He wrote the app in Python; I wrote it in Elixir. Turns out the API's of the various exchanges are (or were) atrocio…

So, both of you guys talk about API request handling. How about some computational task where coding only the happy path means accurate calculated results for 80% of the cases? I think my problem is the marketing hype with Elixir around "happy path" and "self healing" are too broad and resemble hype more than feature description. I'd be happy if those terms weren't used outside of marketing literature, until we have…

I dunno. I'd say it's rather obvious that it's not a magical solution to everything. For one, Elixir is too slow for computation-heavy stuff.

I just gave an example of how happy path programming works in a use case that is pretty common to my day to day. A lot of other stuff I do is similar enough that the same applies, and that's just my experience, not marketing hype.

Some articles might be a little over-excited, but I don't think I've generally read articles that claim Elixir is God's gift to programmers ;). And in situations where Elixir does help, it can be very exciting.

Re: LFE: Lisp Flavored Erlang

#33

Post by whynotwhynot » Mon, Aug 17, 2020, 6:23 PM UTC

mercer wrote: post #32

whynotwhynot wrote: post #30

Earlier quoted context omitted.

So, both of you guys talk about API request handling. How about some computational task where coding only the happy path means accurate calculated results for 80% of the cases? I think my problem is the marketing hype with Elixir around "happy path" and "self healing" are too broad and resemble hype more than feature description. I'd be happy if those terms weren't used outside of marketing literature, until we have…

I dunno. I'd say it's rather obvious that it's not a magical solution to everything. For one, Elixir is too slow for computation-heavy stuff. I just gave an example of how happy path programming works in a use case that is pretty common to my day to day. A lot of other stuff I do is similar enough that the same applies, and that's just my experience, not marketing hype. Some articles might be a little over-excited, b…

Fair enough. Could you please describe other happy path scenarios? Is there an educational resource (blog post maybe?) that talks in depth about "happy path programming" in the general sense? Same applies to "self healing" I really want to know what the folks who came up with these phrases meant, in both specifics and the bigger picture. Thank you for the enlightenment so far!

FWIW, I wasn't aware that Elixir is not optimal for CPU-bound tasks. I use Go for highly concurrent servers, but it uses goroutines not a process per request, and mutexes and/or persistent channels to synchronize shared memory access.