From: Steven Shaw <steven_shaw@...>
Date: 2003-06-02T19:24:40+09:00
Subject: Re: expandtabs

> Anybody have a test suite?

No but here's the test script I've been using. It has all the different
methods from the FAQ and the ones posted here. Your method works on my test
data.


def method1(s)
  def sub_line(a)
    1 while a.sub!(/(^[^\t]*)\t(\t*)/){$1+' '*(8-$1.size%8+8*$2.size)}
    a
  end

  result = ""
  s.each { |line| result << sub_line(line) }
  result
end

def method2(s)
  def sub_line(a)
    1 while a.sub!(/\t(\t*)/){' '*(8-$~.begin(0)%8+8*$1.size)}
    a
  end

  result = ""
  s.each { | line | result << sub_line(line) }
  result
end

def method3(s)
  def sub_line(a)
    a.gsub!(/([^\t]{8})|([^\t]*)\t/n){[$+].pack("A8")}
    a
  end

  result = ""
  s.each { | line | result << sub_line(line) }
  result
end

def method4(a)
  b = ''
  l = 1
  0.upto(a.length) { |i|
    case a[i]
    when 9
      b += ' '
      l += 1
      while l % 8 != 0
        b += ' '
        l += 1
      end
    when 10
      b += a[i..i]
      l = 1
    else
      b += a[i..i]
      l += 1
    end
  }
  return b
end

def method5(data, indent=8)
    x = 0
    i = 0
    while i < data.length
        case data[i]
        when 9
            add = indent - (x % indent)
            data[i..i] = ' '*add
            x += add
            i += add
        when 10
            x = 0
            i += 1
        else
            x += 1
            i += 1
        end
    end
    data
end

def method6(data, indent=8)
  data.gsub(/([^\t\n]*)\t/) {
    $1 + " " * (indent - ($1.size % indent))
  }
end

def println(*s)
  print s, "\n"
end

string = ""
(0..10).each {|n|
  string << "blah\t" + (" " * n) + "blah\n"
}
(0..10).each {|n|
  string << "blah" + (" " * n) + "\tblah\n"
}

println "-- original string"
println(string)

# construct correct answer from method1
$correct = method1(string.clone)

def test_it(result)
  print result
  if result == $correct
    println "result is correct"
  else
    println "result in incorrect"
  end
  println
end

println "-- method2"
test_it(method2(string.clone))

println "-- method3"
test_it(method3(string.clone))

println "-- method4"
test_it(method4(string.clone))

println "-- method5"
test_it(method5(string.clone))

println "-- method6"
test_it(method6(string.clone))


Sorry about my code. I'm just learning Ruby. What's the opposite of split?