Combination for boolean value array

rubyonrails-talk
1

def conditions_combination step_conditions_labels

conditions_combination_hash = Hash.new

1.upto(step_conditions_labels.size).flat_map do |n|

conditions_combination = “”

step_conditions_labels.permutation(n).map { |condition|

if condition.length == n

conditions_combination += "( "

condition.each do |condition_label|

conditions_combination += condition_label+" && "

end

conditions_combination = conditions_combination.chomp(’ && ')

conditions_combination += " ) || "

end

conditions_combination_hash[n.to_s] = conditions_combination.chomp(’ || ‘).chomp(’ && ')

}

end

cond = false

condition_check = conditions_combination_hash[step_conditions_labels.length.to_s]

if condition_check

cond = true

end

return cond

end

I have created this function

conditions_combination_hash = conditions_combination([‘true’,‘false’,‘true’])

which gives me different combination like this

{“1”=>“( true ) || ( false ) || ( true )”, “2”=>“( true && false ) || ( true && true ) || ( false && true ) || ( false && true ) || ( true && true ) || ( true && false )”, “3”=>“( true && false && true ) || ( true && true && false ) || ( false && true && true ) || ( false && true && true ) || ( true && true && false ) || ( true && false && true )”}

Issue is now I am not able use this combination to check whether it satisfies the condition as it is consider as string class.

2

You probably could use something like eval. That being said, if you refactor in order to avoid this, it should lead to clearer, safer code

3

If I saw something like that in a PR I would reject it in ~2 seconds.

What actual problem are you trying to solve?

4

Hi Sapna,

This is a fun exercise to do and also to do some refactoring after I got to understand what you are aiming to do.

First of all, your code is not optimal yet. Let’s look at the output of the example you gave:

{“1”=>“( true ) || ( false ) || ( true )”, “2”=>“( true && false ) || ( true && true ) || ( false && true ) || ( false && true ) || ( true && true ) || ( true && false )”, “3”=>“( true && false && true ) || ( true && true && false ) || ( false && true && true ) || ( false && true && true ) || ( true && true && false ) || ( true && false && true )”}

The combination of 2 and 3 have duplicated information. For example: (true && false && true) are the same as (true && true && false). I have provided a solution for what I understood from your problem below with some comments.

I am considering that you need to solve this in one method, otherwise, I would split in many different methods to make the code more clear. I am also being very cheeky here to introduce many features of the language that would make your life easier and your code much more understandable.

I hope this helps.

Evaluate the combinations of conditions.

5

Hello Marco,

Thank you for replying to the query with detailed explanation. This is what I wanted to do in my code but the code was not clear but you tried to understand my issue and provided the solution so thanks for that. I was not aware with the combination method before.