#charset "us-ascii"
/*
* Copyright (c) 2001, 2006 Michael J. Roberts
*
* This file is part of TADS 3.
*
* This header defines the CharacterSet intrinsic class.
*/
#ifndef _CHARSET_H_
#define _CHARSET_H_
/* include our base class definition */
#include "systype.h"
/*
* 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
{
/*
* Constructor:
*
* new CharacterSet(charsetName) - creates an object to represent the
* named local character set. Certain character set names are
* pre-defined:
*
* us-ascii - the plain 7-bit ASCII character set
*. utf-8 - Unicode UTF-8 (a multi-byte unicode encoding)
*. utf-16le - little-endian 16-bit Unicode
*. utf-16be - big-endian 16-bit Unicode
*
* In addition, any character set for which the VM has an external
* mapping file can be used. Check your platform-specific T3
* installation notes for infomration on how character set mapping
* files are implemented on your version of T3.
*
* A CharacterSet can be created for a non-existent mapping, but the
* object cannot be used to perform any mappings; an
* UnknownCharacterSetException will be thrown if any mapping is
* attempted with a CharacterSet object that has non-existent local
* mappings. You can determine if the local 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.
*/
getName();
/*
* 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.
*/
isMappingKnown();
/*
* 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.
*/
isMappable(val);
/*
* 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
* representation).
*/
isRoundTripMappable(val);
}
#endif /* _CHARSET_H_ */
TADS 3 Library Manual
Generated on 9/8/2006 from TADS version 3.0.11