Ruby regular expression for German texts

ruby-re-german.rb

#!/bin/ruby

# uppercase characters
uchar = 'A-ZÄÖÜÁÀÉÈ'
# lowercase characters
lchar = 'a-zäöüßáàéè'
# all characters
char = uchar + lchar

# whitespace characters
space_char = ' '

# whitespace
space = '(?:[' + space_char + ']+)'

# hyphens
hyphen = '(?:' + space + '(?:--|-|–|—)' + space + ')'

# end of word
eow = '(?:' + space + '|,' + space + '|;' + space + '|\.' + space + '(?![A-Z]))'

# end of sentence
eos_char = '\\.\\?\\!…'
eos = '(?:[' + eos_char + ']+)'

# uppercase word
uword = '[' + uchar + '+]'

# lowercase word
lword = '[' + lchar + '+]'

# capital word
cword = '[' + uchar + '][' + char + ']*'

# any word
word = '[' + char + ']+'

# before word
before_word = '(?:' + eow + '|' + hyphen + ')'

# bracket text
in_bracket = '(?:' + word + '(?:' + before_word + word + ')*)'
bracket_round = '\\(' + in_bracket + '\\)'
bracket_square = '\\[' + in_bracket + '\\]'
bracket_curly = '\\{' + in_bracket + '\\}'
brackets = '(?:' + [bracket_round, bracket_square, bracket_curly].join('|') + ')'

# quoted text
in_quote = in_bracket + ",?"
quote_german = '„' + in_quote + '“'
quote_double = '"' + in_quote + '"'
quote_single = "'" + in_quote + "'"
quotes = '(?:' + [quote_german, quote_double,quote_single].join('|') + ')'

# sentence
sentence = cword + '(?:' + before_word + '(?:' + [word,brackets,quotes].join('|') + '))+' + eos