CODEWITHSUNDEEP
ruby
Cameron Martin
Cameron Martin

Reputation: 6012

Ruby evaluation order

print sentence.scan(/\[(\w+)\]/).all? do |word|
    @words.keys.include? word[0].to_sym
end

I've printed the individual values of @words.keys.include? word[0].to_sym and they are not all true, yet it prints true. I think this might be because its evaluated like so:

(print sentence.scan(/\[(\w+)\]/).all?) do |word|
    @words.keys.include? word[0].to_sym
end

but I want it to evaluate like

print (sentence.scan(/\[(\w+)\]/).all? do |word|
    @words.keys.include? word[0].to_sym
end)

However, adding the parentheses results in

syntax error, unexpected keyword_do_block, expecting ')'

How do I change the order in which the piece of code is evaluated?

Edit:

I would like to return true instead of print unless the above is true, like:

    @sentences.reject do |sentence|
        !(sentence.scan(/\[(\w+)\]/).all? { |word| @words.keys.include? word[0].to_sym })
    end

But it rejects everything.

Upvotes: 1

Views: 175

Answers (2)

megas
megas

Reputation: 21791

This variant works for me:

print (sentence.scan(/\[(\w+)\]/).all?{|word| words.keys.include? word[0].to_sym })

Second variant:

print begin
  (sentence.scan(/\[(\w+)\]/).all? do |word|
    words.keys.include? word[0].to_sym
  end)    
end

Upvotes: 3

Todd A. Jacobs
Todd A. Jacobs

Reputation: 84343

You are creating pain for yourself in a couple of ways:

  1. The argument to print is ambiguous. You should use print(...) with no spaces.

  2. Do/end binds less tightly than a {...} block. Again, your example is somewhat ambiguous for the parser.

Try the less ambiguous syntax, and see if that clears things up before looking at alternative constructions.

Upvotes: 4

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