#!/usr/bin/env ruby

# This is one of several little programs to attempt to test the speed of
# various means of using an RE to search a string.

# This is the default case, which simply checks the string using the RE.

# "[" is ASCII 91

s1 = "This is a test."
s2 = "Wednesday is another day."
s3 = "---*** A Possible Heading"
s4 = "   * A possible list item"
s5 = "A long string with a link hidden within, in other words, [[Web.WikiHome][a link]]."

# The following RE is not exactly correct, but I think it will serve for test purposes.

# The "-6" below is on the assumption that the RE requires at least 6 characters # to match--I might have that number wrong, but there is a right number.

# I'm not at all sure that the code "around" the RE is at all efficient, there 
# may be much better ways to iterate through the string.

# Basically, the idea is, scan through the string looking for a "[", if found, 
# invoke the RE on the substring starting from the found location to the end.  
# (Since it already found one "[" the RE only searches for one more at the 
# beginning of the string.  The RE does not attempt to handle the !, which 
# "escapes" the link.

time_start = Time::now

# with times

10000.times do

  (s1.length-6).times do |i|
    if s1[i] == ?[
      s1[i,s1.length] =~ /\A\[(([A-Z]\w*)\.)?(.*)(#([A-Z]\w*))?\](\[(.*)\])?\]/
    end
  end

  (s2.length-6).times do |i|
    if s2[i] == ?[
      s2[i,s2.length] =~ /\A\[(([A-Z]\w*)\.)?(.*)(#([A-Z]\w*))?\](\[(.*)\])?\]/
    end
  end

  (s3.length-6).times do |i|
    if s3[i] == ?[
      s3[i,s3.length] =~ /\A\[(([A-Z]\w*)\.)?(.*)(#([A-Z]\w*))?\](\[(.*)\])?\]/
    end
  end

  (s4.length-6).times do |i|
    if s4[i] == ?[
      s4[i,s4.length] =~ /\A\[(([A-Z]\w*)\.)?(.*)(#([A-Z]\w*))?\](\[(.*)\])?\]/
    end
  end

  (s5.length-6).times do |i|
    if s5[i] == ?[
      s5[i,s5.length] =~ /\A\[(([A-Z]\w*)\.)?(.*)(#([A-Z]\w*))?\](\[(.*)\])?\]/
    end
  end

end

puts (Time::now - time_start).to_s
puts $&