CONCEPT
        unicode

DESCRIPTION
        LPC strings come in two flavors: As byte sequences and as unicode
        strings. For both types almost the full range of string operations
        is available, but the types are not to be mixed. So for example
        you cannot add a byte sequence to an unicode string or vice versa.

        Byte sequences can store only bytes (values from 0 to 255),
        but unicode strings can store the full unicode character set
        (values from 0 to 1114111).

        There are two conversion functions to convert between byte sequences
        and unicode strings: to_text() which will return a unicode string,
        and to_bytes() which returns a byte sequence. Both take either
        a string or an array, and when converting between bytes and unicode
        also the name of the encoding (to be) used for the byte sequence.

        -- File handling --

        When a file is accessed either by compiling, read_file(), write_file()
        (not read_bytes() or write_bytes(), or when an explicit encoding was
        given), the master is asked via the driver hook H_FILE_ENCODING for
        the encoding of the file. If none is given, 7 bit ASCII is assumed.
        Whenever codes are encounted that are not valid in the given encoding
        a compile or runtime error will be raised.

        -- File names --

        The filesystem encoding can be set with a call to
        configure_driver(DC_FILESYSTEM_ENCODING, <encoding>). The default
        encoding is derived from the LC_CTYPE environment setting.
        If there is no environment setting (or it is set to the default
        "C" locale), then UTF-8 is used.

        -- Interactives --

        Each interactive has its own encoding. It can be set with
        configure_interactive(IC_ENCODING, <encoding>). The default is
        "ISO-8859-1//TRANSLIT" which maps each incoming byte to the
        first 256 unicode characters and uses transliteration to encode
        characters that are not in this character set. If an input or
        output character can not be converted to/from the configured
        encoding it will be silently discarded.

        -- ERQ / UDP --

        Only byte sequences can be sent to the ERQ or via UDP,
        and only byte sequences can be received from them.

HISTORY
        Introduced in LDMud 3.6.

SEE ALSO
        to_text(E), to_bytes(E), configure_driver(E)