It would be great to come up with some kind of heuristic and/or consistent
philosophy on what belongs in the standard library, to guide these discussions.
Some kind of rubric could make these kinds of conversations easier or even
prevent them entirely. For me, the main guiding principles are whether or not
there is exactly one right way to do the thing in question, how ubiquitous the
need for it is, and how obvious the implementation is (on the flipside, how
much we can prevent people from hidden gotchas they wouldn't even think to
reach for a library for).
For example, the implementation actually requires only adding padding if the
string has been trimmed at all, and I'd bet there are lots of suboptimal
implementations out there. Ben's above isn't quite right, since the idea is to
only add the ellipses if it truncated the string, and then it should only add
exactly the string provided (not pad it out to the full length of the string).
Since a performant implementation probably might not be quite as obvious to the
less experienced (with elixir or in general), and this seems like a relatively
common operation (for rendering strings in UIs or emails or w/e), I feel like a
std library implementation could be warranted.
Something like this would probably be better since it avoids checking the
string length (a linear time operation) and also avoids things like multiple
slice operations in favor of a single traversal up to "length".
```
def truncate("", 0, _), do: ""
def truncate(_, 0, padding), do: padding
def truncate(string, length, padding) when length > 0 do
case String.split_at(string, length) do
{leading, ""} -> leading
{leading, _} -> leading <> padding
end
end
```
On Sat, Nov 19 2022 at 9:45 PM, Ben Wilson < benwilson...@gmail.com > wrote:
>
> This seems reasonably straight forward to implement in your own code base:
>
>
>
> ```
> def truncate(string, length, padding \\ ".") do
> string
> |> String.slice(0, length)
> |> String.pad_trailing(String.length(string), padding)
> end
> ```
>
>
> Not seeing a strong need to include it in the standard library. Just my
> $0.02
> On Saturday, November 19, 2022 at 2:12:19 PM UTC-5 Kip wrote:
>
>
>> That is comes from Laravel, not PHP core may be an indication it is better
>> implemented in a library? If there is momentum towards adding it to the
>> String module I think `String.truncate` would feel more natural to me (its
>> also what Ruby uses).
>>
>>
>> Its difficult to make guarantees about the printable width though since
>> characters like ZWJ and Bidi text would mean that to do this properly is
>> not a simple or straight forward situation. For that reason I don't
>> personally think it belongs in Elixir itself.
>>
>>
>> On Saturday, November 19, 2022 at 5:20:21 PM UTC+1 hassanr...@gmail.com
>> wrote:
>>
>>
>>
>>> Hi all,
>>> I came across from laravel ( https://laravel.com ) framework, where there
>>> are a lot of useful functions, I miss those functions in Elixir, One of
>>> the functions is called limit (
>>> https://laravel.com/docs/9.x/helpers#method-str-limit ) function, I would
>>> like to have that in elixir.
>>> ```
>>> iex> String.limit("elixir", 3)
>>> "eli..."
>>>
>>> iex> String.limit("elixir", 7)
>>> "elixir"
>>>
>>>
>>> iex> String.limit("elixir", 3, "***")
>>> "eli***"
>>> ```
>>> This function would be really helpful with longer string, we can limit
>>> long string with some trailing string like (...).
>>>
>>> What do you think? If yes what should be the name you suggest?
>>>
>>> Thanks,
>>> Hassan
>>>
>>>
>>>
>>>
>>>
>>
>>
>
>
>
>
>
> --
> You received this message because you are subscribed to the Google Groups
> "elixir-lang-core" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to elixir-lang-core+unsubscr...@googlegroups.com.
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/elixir-lang-core/35628c34-c8c4-4558-a985-de87ec7111d3n%40googlegroups.com
> (
> https://groups.google.com/d/msgid/elixir-lang-core/35628c34-c8c4-4558-a985-de87ec7111d3n%40googlegroups.com?utm_medium=email&utm_source=footer
> ).
>
>
--
You received this message because you are subscribed to the Google Groups
"elixir-lang-core" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to elixir-lang-core+unsubscr...@googlegroups.com.
To view this discussion on the web visit
https://groups.google.com/d/msgid/elixir-lang-core/laoukpzy.f4712342-a7c6-40db-bf00-87e6b393bcd1%40we.are.superhuman.com.
