Suppose I have a UTF-8 string and want to know how many default grapheme clusters it contains. How do I do so? Well, I step through the string character by character, combining successive characters into grapheme clusters. To do this without having to decode the UTF-8 myself, I need to be able to get at the string character by character, and very likely use a loop based on the number of characters in the string, e.g. the following Basic (horrid language but good for making my point here):
For i% = 1 to Len(utf8string$) c$ = Mid(utf8string$, i%, 1) Process c$ Next i%
Such a loop would be more efficient in UTF-32 of course, but this is still a real need for working with character counts.
Why use a horrid language when there's a nice one? :
#!/usr/bin/perl
use utf8 ; # not needed (and ignored) in Perl 5.8.*
my $string = "alpha \x{03b1}\ntagspace \x{e0020}" ;
my @utf8chars = split //, $string ;
foreach my $char(@utf8chars) {
my $len = length unpack "a*", $char;
print "$char\[$len\]" ;
}### a[1]l[1]p[1]h[1]a[1] [1]α[2] ### [1]t[1]a[1]g[1]s[1]p[1]a[1]c[1]e[1] [1][4]
