Determine if a string is collapsible

func squeeze(str) {
    str.gsub(/(.)\1+/, {|s1| s1 })

var strings = ["",
        '"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ',
        "I never give 'em hell, I just tell the truth, and they think it's hell. ",
        "                                                   ---  Harry S Truman  ",
        "The better the 4-wheel drive, the further you'll be from help when ya get stuck!",

strings.each {|str|
    var ssq = squeeze(str)
    say "«««#{str}»»» (length: #{str.len})"
    say "«««#{ssq}»»» (length: #{ssq.len})\n"