> For the complete documentation index, see [llms.txt](https://trizen.gitbook.io/sidef-lang/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://trizen.gitbook.io/sidef-lang/programming_tasks/i/interactive_programming_repl.md).

# Interactive programming repl

```ruby
$ sidef -i
>>> func f(s1, s2, sep) { s1 + sep*2 + s2 };
f
>>> f('Rosetta', 'Code', ':')
"Rosetta::Code"
>>> 
```