
sprite2005
Concurrent Data Processing in Elixir: Using a mapper operation after reduce/3 is deprecated (page 114)
@svilen
warning: Using a mapper operation, such as map/filter/reject, after reduce/3 is deprecated. Use Flow.on_trigger/2 instead
(flow 1.2.0) lib/flow.ex:1916: Flow.add_mapper/3
(airports 0.1.0) lib/airports.ex:25: Airports.open_airports/0
(stdlib 4.0.1) erl_eval.erl:744: :erl_eval.do_apply/7
(elixir 1.13.4) src/elixir.erl:296: :elixir.recur_eval/3
(elixir 1.13.4) src/elixir.erl:274: :elixir.eval_forms/3
(iex 1.13.4) lib/iex/evaluator.ex:310: IEx.Evaluator.handle_eval/3
How would we rewrite this as an on_trigger function?
Popular Prag Prog topics

Following the steps described in Chapter 6 of the book, I’m stuck with running the migration as described on page 84:
bundle exec sequel...
New

Python Testing With Pytest - Chapter 2, warnings for “unregistered custom marks”
While running the smoke tests in Chapter 2, I get these...
New

your book suggests to use Image.toByteData() to convert image to bytes, however I get the following error: "the getter ‘toByteData’ isn’t...
New

I can’t setup the Rails source code. This happens in a working directory containing multiple (postgres) Rails apps.
With:
ruby-3.0.0
s...
New

Page 28: It implements io.ReaderAt on the store type.
Sorry if it’s a dumb question but was the io.ReaderAt supposed to be io.ReadAt?
...
New

Hi @venkats,
It has been mentioned in the description of ‘Supervisory Job’ title that 2 things as mentioned below result in the same eff...
New

In case this helps anyone, I’ve had issues setting up the rails source code. Here were the solutions:
In Gemfile, change
gem 'rails'
t...
New

Hello! Thanks for the great book.
I was attempting the Trie (chap 17) exercises and for number 4 the solution provided for the autocorre...
New

I ran this command after installing the sample application:
$ cards add do something --owner Brian
And got a file not found error:
Fil...
New

Hello faithful readers! If you have tried to follow along in the book, you are asked to start up the dev environment via dx/build and ar...
New
Other popular topics

I know that these benchmarks might not be the exact picture of real-world scenario, but still I expect a Rust web framework performing a ...
New

A PragProg Hero’s Journey with Brian P. Hogan @bphogan
Have you ever worried that your only legacy will be in the form of legacy...
New

I know that -t flag is used along with -i flag for getting an interactive shell. But I cannot digest what the man page for docker run com...
New
New

Inspired by this post from @Carter, which languages, frameworks or other tech or tools do you think is killing it right now? :upside_down...
New

If you are experiencing Rails console using 100% CPU on your dev machine, then updating your development and test gems might fix the issu...
New

Learn different ways of writing concurrent code in Elixir and increase your application's performance, without sacrificing scalability or...
New

Continuing the discussion from Thinking about learning Crystal, let’s discuss - I was wondering which languages don’t GC - maybe we can c...
New

We’ve talked about his book briefly here but it is quickly becoming obsolete - so he’s decided to create a series of 7 podcasts, the firs...
New

Author Spotlight:
Bruce Tate
@redrapids
Programming languages always emerge out of need, and if that’s not always true, they’re defin...
New
Latest in PragProg
Latest (all)
Categories:
Popular Portals
- /elixir
- /rust
- /wasm
- /ruby
- /erlang
- /phoenix
- /keyboards
- /js
- /rails
- /python
- /security
- /go
- /swift
- /vim
- /clojure
- /java
- /haskell
- /emacs
- /svelte
- /onivim
- /typescript
- /crystal
- /c-plus-plus
- /tailwind
- /kotlin
- /gleam
- /react
- /flutter
- /elm
- /ocaml
- /vscode
- /opensuse
- /centos
- /ash
- /php
- /deepseek
- /scala
- /zig
- /html
- /debian
- /nixos
- /lisp
- /agda
- /sublime-text
- /textmate
- /react-native
- /kubuntu
- /arch-linux
- /revery
- /ubuntu
- /manjaro
- /django
- /spring
- /diversity
- /nodejs
- /lua
- /slackware
- /julia
- /c
- /neovim