Flip strings.join
%blame% (%tag% "not a string" l),
// using a contract instead of type for now because of https://github.com/tweag/nickel/issues/226
- join | List Str -> Str -> Str
+ join | Str -> List Str -> Str
| doc m#"
Joins a list of strings given a seperator.
For example:
```nickel
- join [ "Hello", "World!" ] ", " =>
+ join ", " [ "Hello", "World!" ] =>
"Hello, World!"
```
"#m
- = fun l sep =>
+ = fun sep l =>
if %length% l == 0 then
""
else
