Ruby on Rails

On Feb 22, 2019, at 3:10 PM, Marco Antonio Almeida <marcoafilho@gmail.com> wrote:

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.

#

# step_conditions_labels - The Array of conditions.

#

# Examples

#

# conditions_combination(%w[true false true])

# # => {1=>true, 2=>true, 3=>false}

#

# conditions_combination(%w[true false true false true])

# # => {1=>true, 2=>true, 3=>true, 4=>false, 5=>false}

#

# Returns a hash of the evaluation of respective combinations.

def conditions_combination(step_conditions_labels)

  # Reduce the Array to the result Hash.

  step_conditions_labels.each_with_index.reduce({}) do |hash, (_, index)|

    # Update each of the Hash keys with the evalutation of the combination.

    hash.update(

      index + 1 =>

        # Eval is the way to go here as Tales mentioned, but it's a very

        # dangerous method. Be careful!

        eval(

          # Array#combination is what does the trick for you. Check it out:

          # https://ruby-doc.org/core-2.6.1/Array.html#method-i-combination

          # The other lines just help on building the condition String.

          step_conditions_labels

            .combination(index + 1)

            .map { |combination| "(#{combination.join(' && ')})" }

            .join(' || ')

        )

    )

  end

end

conditions_combination(%w[true false true])

Best regards,

/ Marco

On Fri, Feb 22, 2019 at 6:56 PM Hassan Schroeder <hassan.schroeder@gmail.com> wrote:

On Fri, Feb 22, 2019 at 4:36 AM Sapna Mishra <sapna.spaceo@gmail.com> wrote:

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

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

What actual problem are you trying to solve?

-- 
Hassan Schroeder ------------------------ hassan.schroeder@gmail.com
twitter: @hassan
Consulting Availability : Silicon Valley or remote

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