Normal strings contain characters with character codes between 0
and 255, so-called 8-bit characters. But Pike can also handle strings
with characters with higher character codes. This is needed for some
languages, such as Japanese. Such strings are called wide
strings:
"The character \x123456 is the same as \d1193046."
This string contains two occurrences of the character with
(decimal) character code 1193046. As you may remember, Pike will
translate \x followed by a hexadecimal (that is, base 16) number in a
string literal to the character with that character code. The same is
true for \d followed by a decimal (that is, normal base 10) number,
and for a single \ followed by an octal (base 8) number.
Internally, Pike will handle wide strings differently from normal
8-bit strings, but as a Pike programmer, you will usually not need to
worry about the difference. Just use the characters you need. There
may however be some operations, for example certain methods in certain
modules, that cannot handle wide strings but that work with 8-bit
strings. This is seldom intentilnal, and should you stumble upon one,
please report it to us in
Bug Crunch, our bug
tracking system at Roxen Internet Software, and we'll try to fix it as
soon as time allows.
Here are some functions that can be used to examine wide
strings:
- String.width(string data)
This gives the width of the string data. This width of a
string is the number of bits that is used to store each character in
the string. Normal strings are 8 bits wide, but strings can also be 16
or 32 bits wide. For each string, Pike will use as few bits as
possible. For example, "foo" will be 8 bits wide,
"foo\d255" is also 8 bits wide, "foo\d256" is 16
bits wide, and "foo\d70000" is 32 bits wide.
- string_to_utf8(string data)
This translates the string data, which can be a wide string,
to a string in the format UTF8. UTF8 is a format that encodes wide
characters in an 8-bit string.
- utf8_to_string(string utf8_encoded_data)
This translates an UTF8-encoded string utf8_encoded_data
(which, by implication of the nature of the coding, can not be a wide
string, since the UTF8 encoding is 8-bit by definition), to a pike
string.
