is it palandrome, if we only consider numbers and letters

isSomewhatPalandrome.rb

def isSomewhatPalandrome?(word)
  i = 0 
  j = word.length-1 # 1
  
  while(i<j) do
    while ((i < word.length) && !(word[i].match /^[a-zA-Z0-9]$/)) do
      i+=1 # 1
    end
    while ((j > 0) && !(word[j].match /^[a-zA-Z0-9]$/)) do
      j-=1 # j -> 0
    end
    if (
          i <= j &&
          (word[i] != word[j]) &&
          (word[i].upcase != word[j]) &&
          (word[i] != word[j].upcase)
      )    
      return false
    end
    i += 1 # 1
    j -= 1 # 29
  end
  true
end

puts isSomewhatPalandrome?("A man, a plan, a canal, Panama!")

puts isSomewhatPalandrome?("Aan, a plan, a canal, Panama!")

puts isSomewhatPalandrome?(".1.")