CODEWITHSUNDEEP
ruby
oldergod
oldergod

Reputation: 15010

String of int and range to array of int (Looking for improvement)

First, what I have:

s = "1,3..5,8"

What I want:

["1", "3", "4", "5", "8"]

I found a way with as below

r = s.split(/\s?,\s?/)
=> ["10", "12..15", "17", "
r.map do |c|
  if Fixnum === eval(c)
    c
  else
    eval(c).map(&:to_s).flatten
  end
end
=> ["10", "12", "13", "14", "15", "17", "18"]

Would there be a better way to achieve this?

Upvotes: 2

Views: 168

Answers (4)

Jon Snow
Jon Snow

Reputation: 11882

How about this way:

s='1,2..6,10'

s.split(',').map { |e| e.strip.include?('..') ? eval("(#{e}).to_a") : e.to_i }.flatten

Upvotes: 0

Jakobinsky
Jakobinsky

Reputation: 1294

I wouldn't use eval.

A marginally better way would be:

s = "1,3...5,8"
p s.split(',').map { |n|
  if n.scan('...').empty?
    n
  else
    Range.new(*n.split('...', 2)).to_a
  end
}.flatten
# => ["1", "3", "4", "5", "8"]

EDIT: Fixed the code as suggested by @fl00r to work with multiple digit numbers.

Upvotes: 4

peter
peter

Reputation: 42192

s = "10,12...15,17" 
s.split(',').map { |n| n['...'] ? Range.new(*n.split('...', 2)).to_a : n}.flatten 
#=> ["10", "12", "13", "14", "15", "17"]

Upvotes: 1

fl00r
fl00r

Reputation: 83680

def magick(str)
  str.split(",").map do |item|
    item.scan(/(\d+)(\.+)(\d+)/)
    if $1
      Range.new($1.to_i, $3.to_i, $2 == "...").to_a
    else
      item.to_i
    end
  end.flatten
end

s1 = "1,3..5,8"
s2 = "1,3...5,8,20,100, 135"
magick(s1)
#=> [1, 3, 4, 5, 8]
magick(s2)
#=> [1, 3, 4, 8, 20, 100, 135]

Upvotes: 2

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