Elixir: When to use .ex and when .exs files

elixir
Ole Spaarmann picture Ole Spaarmann · Mar 29, 2016 · Viewed 15.4k times · Source

Elixir's documentation states that

In addition to the Elixir file extension .ex, Elixir also supports .exs files for scripting. Elixir treats both files exactly the same way, the only difference is in intention. .ex files are meant to be compiled while .exs files are used for scripting, without the need for compilation.

But I'm still not sure when to use which file type. What are the downsides and the purpose of .ex and .exs?

Answer

Cody Poll picture Cody Poll · Mar 29, 2016

.ex is for compiled code, .exs is for interpreted code.

ExUnit tests, for example, are in .exs files so that you don't have to recompile every time you make a change to your tests. If you're writing scripts or tests, use .exs files. Otherwise, just use .ex files and compile your code.

As far as pros/cons, interpretation will take longer to execute (as elixir has to parse, tokenize, etc.), but doesn't require compilation to run. That's pretty much it - if the flexibility of running scripts is more important than optimized execution time, use .exs. Most of the time, you'll use .ex.

Related questions

How to join strings in Elixir?

How do I join two strings in a list with a space, like: ["StringA", "StringB"] becomes "StringA StringB"

Read More
How do you check for the type of variable in Elixir

In Elixir how do you check for type such as in Python: >>> a = "test" >>> type(a) <type 'str'> >>> b =10 >>> type(b) <type 'int'> I …

Read More
Convert Elixir string to integer or float

I need to convert a string to a floating point value or an integer. There was no method such as, string_to_integer

Read More