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> can someone familiar with both Elixir and Erlang explain what Elixir provides in comparison to Erlang. The syntax is nicer, but that's just a bonus. The rea

by unoti 11y ago

> can someone familiar with both Elixir and Erlang explain what Elixir provides in comparison to Erlang. The syntax is nicer, but that's just a bonus. The real game-changer to me about Elixir vs Erlang is its macro system. This gives you runtime code execution and runtime code generation, similar to what makes LISP to powerful. There's a large amount of boilerplate involved in creating an OTP server, as you know if you've done any Erlang. Elixir's macro capabilities completely eliminate all the boilerplate. The source to both Elixir and Phoenix are quite elegant and educational to browse, and demonstrate this runtime code generation aspect very well. It's straightforward in Elixir to introspect code, represent that code as data structures, manipulate those data structures, then generate or execute that code, as you can in LISP. Elixir also gives a number of excellent tools that streamline the support process over vanilla Erlang. For example, Elixir's runtime tooling automatically manages dependencies for you (similar to node's npm), and automatically maintains the application string that you need to provide for all OTP applications. It also has improved capabilities for testing, which are also made possible by the amazing macro generation capabilities. > I'm looking into using Erlang for a new project that requires extensive scaling and concurrency and am coming from a functional background so may be more comfortable with the traditional Erlang syntax Elixir's syntax is still just as functional. They support a regular if statement, unlike Erlang, but generally it's just as functional as Erlang. Elixir eliminates a number of needless chores from Erlang, such as having to end some lines of code with a comma, and others with a period, and then shuffling punctuation around whenever you add or remove lines of code. That's a task I used to do literally a hundred times a day in Erlang that I don't have to do at all any more.

vezzy-fnord 11y ago
You can do reasonable metaprogramming in Erlang with the syntax_tools and stdlib interfaces. Most famously was bringing back parameterized modules via a parser transformation for tools like BossDB to support ActiveRecord-like ORM patterns. I've looked at OTP the Elixir way and I do not see any real boilerplate reduction. The application-project dichotomy and the opinionated integration with a tool like Mix is also policy over mechanism. rebar3 does fine dependency management given its constraints of having to unify packages coming from disparate sources. The syntax is not nicer. It is a jarring conceptual mismatch to put Smalltalk-ish Ruby syntax over a language that eschews excessive monkey patching and dynamism like Erlang.
- haddadell 11y ago
  > You can do reasonable metaprogramming in Erlang with the syntax_tools and stdlib interfaces. You can also do concurrency in Ruby. It is not the same as doing concurrency in Erlang though. The same way doing metaprogramming with syntax tools, parse transforms and what not is nowhere close to a macro system. > I've looked at OTP the Elixir way and I do not see any real boilerplate reduction. So please look again? Take a look at Elixir's agents or tasks and explain how it doesn't lead to more readable and cleaner code than the GenServer equivalent in Erlang for the cases they fit. You could maybe point other criticism but saying "no real boilerplate reduction" just shows you didn't really try or care to give it a try. > It is a jarring conceptual mismatch to put Smalltalk-ish Ruby syntax over a language that eschews excessive monkey patching and dynamism like Erlang. This sentence is specially ironic given that Erlang inherits from Prolog, which is quite different semantically from Erlang, instead of using the more tradicional ML families. Also Erlang is pretty much a very dynamic language. I am a Haskell developer, I hate Ruby syntax and I programmed Erlang for a year. I would still choose Elixir over Erlang any day mostly because of the tooling, typeclass like polymorphism and the new abstractions (Task and Agent).
  - vezzy-fnord 11y ago
    The same way doing metaprogramming with syntax tools, parse transforms and what not is nowhere close to a macro system. I'd wager that's because no one has written tooling to make it compelling to the common programmer. Same with release management for a long time, and hot code reloading. I'd understand if you said that basic substitution macros are nowhere close to actual AST macros, but Erlang has far more than that. Take a look at Elixir's agents or tasks and explain how it doesn't lead to more readable and cleaner code than the GenServer equivalent in Erlang for the cases they fit. Those are sugar. It's not like you can't define your own behaviors in Erlang. People do it all the time, there's so many good libraries that go beyond stock OTP. I should really switch an entire language because of default libraries? This sentence is specially ironic given that Erlang inherits from Prolog, which is quite different semantically from Erlang Only traces. The Prolog influence of Erlang is severely overrated by a lot of people these days. Also Erlang is pretty much a very dynamic language. It ain't no Smalltalk. The runtime is very dynamic, and the typing is loose, but the Erlang language itself not so much, which I think is a strength. I am a Haskell developer, I hate Ruby syntax and I programmed Erlang for a year. Good for you, chap.

by unoti 11y ago

vezzy-fnord 11y ago

You can do reasonable metaprogramming in Erlang with the syntax_tools and stdlib interfaces. Most famously was bringing back parameterized modules via a parser transformation for tools like BossDB to support ActiveRecord-like ORM patterns. I've looked at OTP the Elixir way and I do not see any real boilerplate reduction. The application-project dichotomy and the opinionated integration with a tool like Mix is also policy over mechanism. rebar3 does fine dependency management given its constraints of having to unify packages coming from disparate sources. The syntax is not nicer. It is a jarring conceptual mismatch to put Smalltalk-ish Ruby syntax over a language that eschews excessive monkey patching and dynamism like Erlang.

haddadell 11y ago
> You can do reasonable metaprogramming in Erlang with the syntax_tools and stdlib interfaces. You can also do concurrency in Ruby. It is not the same as doing concurrency in Erlang though. The same way doing metaprogramming with syntax tools, parse transforms and what not is nowhere close to a macro system. > I've looked at OTP the Elixir way and I do not see any real boilerplate reduction. So please look again? Take a look at Elixir's agents or tasks and explain how it doesn't lead to more readable and cleaner code than the GenServer equivalent in Erlang for the cases they fit. You could maybe point other criticism but saying "no real boilerplate reduction" just shows you didn't really try or care to give it a try. > It is a jarring conceptual mismatch to put Smalltalk-ish Ruby syntax over a language that eschews excessive monkey patching and dynamism like Erlang. This sentence is specially ironic given that Erlang inherits from Prolog, which is quite different semantically from Erlang, instead of using the more tradicional ML families. Also Erlang is pretty much a very dynamic language. I am a Haskell developer, I hate Ruby syntax and I programmed Erlang for a year. I would still choose Elixir over Erlang any day mostly because of the tooling, typeclass like polymorphism and the new abstractions (Task and Agent).
- vezzy-fnord 11y ago
  The same way doing metaprogramming with syntax tools, parse transforms and what not is nowhere close to a macro system. I'd wager that's because no one has written tooling to make it compelling to the common programmer. Same with release management for a long time, and hot code reloading. I'd understand if you said that basic substitution macros are nowhere close to actual AST macros, but Erlang has far more than that. Take a look at Elixir's agents or tasks and explain how it doesn't lead to more readable and cleaner code than the GenServer equivalent in Erlang for the cases they fit. Those are sugar. It's not like you can't define your own behaviors in Erlang. People do it all the time, there's so many good libraries that go beyond stock OTP. I should really switch an entire language because of default libraries? This sentence is specially ironic given that Erlang inherits from Prolog, which is quite different semantically from Erlang Only traces. The Prolog influence of Erlang is severely overrated by a lot of people these days. Also Erlang is pretty much a very dynamic language. It ain't no Smalltalk. The runtime is very dynamic, and the typing is loose, but the Erlang language itself not so much, which I think is a strength. I am a Haskell developer, I hate Ruby syntax and I programmed Erlang for a year. Good for you, chap.