Anko
Ordered sorting of a map to a keyword list
Just wondered if there is some standard library function for converting a map to a keyword list, but sorting it on the way.
something like;
map = %{"z" => 4, "y" => 6, "x" => 7}
order = ["x", "y"]
output = new_func(map, order)
# output now equals [{"x", 7}, {"y", 6}]
Marked As Solved
codeanpeace
Here’s one approach:
iex(1)> map = %{"z" => 4, "y" => 6, "x" => 7}
%{"x" => 7, "y" => 6, "z" => 4}
iex(2)> order = ["x", "y"]
["x", "y"]
iex(3)> Enum.map(order, fn key -> {key, Map.get(map, key)} end)
[{"x", 7}, {"y", 6}]
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dimitarvp
No the stdlib does not have that and you’ll see exactly why: it’s easy to do it yourself.
%{"z" => 4, "y" => 6, "x" => 7}
|> Map.take(["x", "y"]) # only take keys "x" and "y"
|> Map.to_list() # convert the map to a list of tuples
|> Enum.sort_by(fn {key, _value} -> key end) # sort the list of tuples by their first element
And you will get [{"x", 7}, {"y", 6}] as your result.
adamu
I said something similar 3 years ago 
(actually @mudasobwa said it and I got the points. Thanks 
).
dimitarvp
Sure, you can just put it in your project. Two minute job.
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