Pretty printer should output the maximum it can in one line

[josevalim]

iex(5)> Enum.to_list 1..100
[1,
 2,
 3,
 4,
 5,
 6,
 7,
 8,
 9,
 10,
 11,
 12,
 13,

We should always output the maximum we can into a single line and just then go to the next one using the nesting. @brunoro could you please give us hand? :)

[brunoro]

I think that none of the pretty-printing algorithms I've looked into could handle something like that by itself.
Maybe we could try to regroup short terms somehow to force the pretty printer to behave that way. I'll give it a try ;)

[josevalim]

If it helps, the erlang one does it:

6> io:format("~p~n", [lists:seq(1, 100)]).
[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,
 29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,
 54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,
 79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100]

[brunoro]

It does! Even if the Erlang implementation uses the Hughes algorithm, that behavior is related to the way the document is structured (grouping) rather than to the pretty printer itself.

By looking at http://www.erlang.org/doc/man/prettypr.html I guess we need something like prettypr:par/2. Currently we have something more like prettypr:sep/1 being used for printing sequences.

[gerred]

I'm happy to take this on - where would I look for the existing pretty printing?

[edgurgel]

@gerred, @josevalim was too fast :)