* Copyright (c) 2001, 2006 Michael J. Roberts
* This file is part of TADS 3.
* This header defines the CharacterSet intrinsic class.
/* include our base class definition */
* The CharacterSet intrinsic class provides information on character set
* translations and can be used to translate between the Unicode character
* set that the T3 VM uses internally for string values and the local
* character set or sets used for display, keyboard input, and file I/O.
intrinsic class CharacterSet 'character-set/030001': Object
* new CharacterSet(charsetName) - creates an object to represent the
* named local character set. Certain common character set names are
* built into the system:
* us-ascii - the plain 7-bit ASCII character set
*. latin1 - 8-bit Western Europe extended ASCII (also called ISO 8859-1)
*. utf-8 - Unicode UTF-8 (varying byte length Unicode encoding)
*. utf-16le - little-endian 16-bit Unicode
*. utf-16be - big-endian 16-bit Unicode
* You can extend this basic set using mapping files. You can create
* your own mapping files (see the System Manual to learn how), so
* there's essentially no limit to the character sets that TADS can
* work with. You'll probably never need to create your own custom
* mappings, though, because the standard TADS distributions include a
* large set of pre-built mappings that cover most systems currently in
* use. The standard set includes the various ISO 8859 variants, plus
* proprietary code pages for Windows, DOS, and Mac OS.
* If the named mapping doesn't exist, a CharacterSet object will still
* be created, but it'll throw an error (UnknownCharacterSetException)
* if you attempt to use it to perform any mappings. You can determine
* if the mapping exists with the isMappingKnown method.
* Get the name of the character set. This simply returns the name
* that was given to construct the character set.
* Determine if the mapping is known. This returns true if the
* character set has a known local mapping, nil if not. Note that it
* doesn't matter whether or not the character set is actually in use
* on the local platform; all that matters is that a T3 mapping file
* is available on this machine.
* Determine if a character or string of characters is mappable to this
* character set. If the input is an integer, it represents the
* Unicode character code for a single character; if the input is a
* string, each character in the string is checked. This returns true
* if every character given has a valid mapping in the local character
* set, nil if not. Note that if a string is given, and even one
* character is not mappable, this returns nil.
* Determine if a character or string of characters is "round-trip"
* mappable to this character set. If the input is an integer, it
* represents a Unicode character code to be tested; if the input is a
* string, each character in the string is tested. Returns true if
* every character given has a valid round-trip mapping, nil if not.
* A character has a round-trip mapping if it can be mapped to this
* local character set and then back to Unicode to yield the original
* character. If a character has a round-trip mapping, then in general
* the character has an exact representation in the local character set
* (as opposed to an approximation: if 'a-umlaut' maps to a simple
* unaccented 'a', or to 'ae', then it has only an approximated
TADS 3 Library Manual
Generated on 5/16/2013 from TADS version 3.1.3