# No.31 Perl Sample (code key - 62)
# Learning Perl: Count Word Types 3（単語のタイプ数を数える）
# Tomonori Nagano <tnagano@gc.cuny.edu>
# Last Update: January 18, 2008
#
# This file is encoded in Unicode (UTF-8). If you see gibberish characters, 
# please re-encode the file in utf-8. 
# 

# this sample script is simplified for pedagogical purposes. Those who are
# interested in advanced Perl programming are encouraged to consult with 
# relevant sections of "Perl Cookbook" by Christiansen & Torkington

my $numWords= 0 ;				# define the global variables

while(<>){						# this reads the default file line by line
	tr/A-Z/a-z/ ;				# normalize to lower case
	s/([^\- a-zA-Z0-9])/ \1 /g ;# a negative definition of punctuation
	my @words = split ;			# split $_ into each word; alternatively use split (" ",$_) 
	foreach (@words) {			# process each word
		next if (/[^a-zA-Z]/) ;	# skip if a word contains non-alphabet char
		$numWords++ ;			# increase the count eveyr time
	}
}

print "numWords\t$numWords\n" ;