Unicode - Revision history

Thomas Linder Puls: PFC link to category

2008-10-29T21:15:53Z

PFC link to category

← Older revision		Revision as of 23:15, 29 October 2008
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	=== Unicode support in Visual Prolog ===		=== Unicode support in Visual Prolog ===

	In Visual Prolog the data type <vp>string</vp> represent Unicode strings. 8-bit character strings are represented by the data type <vp>string8</vp>. [[PFC]] by default targets Unicode string support, but some support is given for 8-bit character set support. Files can for example be read and written in 8-bit character sets.		In Visual Prolog the data type <vp>string</vp> represent Unicode strings. 8-bit character strings are represented by the data type <vp>string8</vp>. [[:Category:PFC\|PFC]] by default targets Unicode string support, but some support is given for 8-bit character set support. Files can for example be read and written in 8-bit character sets.

	UTF-8 is represented as <vp>string8</vp> strings.		UTF-8 is represented as <vp>string8</vp> strings.

Thomas Linder Puls: Categorized

2008-10-29T20:56:26Z

Categorized

← Older revision		Revision as of 22:56, 29 October 2008
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	* [[wikipedia:UTF-16]]		* [[wikipedia:UTF-16]]
	* [[wikipedia:Byte-order mark]]		* [[wikipedia:Byte-order mark]]

			[[Category:PFC]]

Thomas Linder Puls: VIP Unicode support

2008-02-03T22:18:07Z

VIP Unicode support

← Older revision		Revision as of 00:18, 4 February 2008
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	A byte-order mark (BOM) is the Unicode character with hex value 0xFEFF.		A byte-order mark (BOM) is the Unicode character with hex value 0xFEFF.

	It is optionally written in the start of Unicode files to clarify the byte order of the file.		It is optionally written in the start of Unicode '''files''' to clarify the byte order of the file.

	{\|{{prettytable}}		{\|{{prettytable}}
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	It is also optionally written in UTF-8 files to indicate that UTF-8 format is used. In UTF-8 the values are <tt>EF BB BF</tt>. It can also be used in other Unicode transfer.		It is also optionally written in UTF-8 files to indicate that UTF-8 format is used. In UTF-8 the values are <tt>EF BB BF</tt>. It can also be used in other Unicode transfer.

			=== Unicode support in Visual Prolog ===

			In Visual Prolog the data type <vp>string</vp> represent Unicode strings. 8-bit character strings are represented by the data type <vp>string8</vp>. [[PFC]] by default targets Unicode string support, but some support is given for 8-bit character set support. Files can for example be read and written in 8-bit character sets.

			UTF-8 is represented as <vp>string8</vp> strings.

			Unicode files created using PFC will get a byte order mark.

			<vip>S = outputStream_file::create("file.text"), % create a Unicode file that starts with a BOM</vip>

			To create a Unicode file without a byte order mark, create the file as an 8-bit file and then change the stream to Unicode format afterwards:

			<vip>S = outputStream_file::create8("file.text"),
			S:setMode(stream::unicode()), % create a Unicode file that starts without a BOM<</vip>

	=== References ===		=== References ===

Thomas Linder Puls: spelling

2008-02-03T21:49:32Z

spelling

← Older revision		Revision as of 23:49, 3 February 2008
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	=== Encoding ===		=== Encoding ===

	Unicode can be encoded in several ways. In Windows (and thus Visual Prolog) the most interesting formats are UTF-8 and UTF-16 (Little Endian). UTF is an ~~actonym~~ for Unicode Transfer Format. UTF-8 is an 8-bit character set encoding where standard ANSII characters are kept as they are and more rare (in western languages) characters are encoded using two, three or four byte character sequences.		Unicode can be encoded in several ways. In Windows (and thus Visual Prolog) the most interesting formats are UTF-8 and UTF-16 (Little Endian). UTF is an acronym for Unicode Transfer Format. UTF-8 is an 8-bit character set encoding where standard ANSII characters are kept as they are and more rare (in western languages) characters are encoded using two, three or four byte character sequences.

	In UTF-16 Little Endian Unicode is encoded using sequences of 1 or 2 16-bit units. UTF-16 is used internally in Windows API calls. Little Endian means that the least ~~signifiant~~ byte of each 16-bit unit is stored before the most significant byte.		In UTF-16 Little Endian Unicode is encoded using sequences of 1 or 2 16-bit units. UTF-16 is used internally in Windows API calls. Little Endian means that the least significant byte of each 16-bit unit is stored before the most significant byte.

	=== Byte-order mark ===		=== Byte-order mark ===
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	A byte-order mark (BOM) is the Unicode character with hex value 0xFEFF.		A byte-order mark (BOM) is the Unicode character with hex value 0xFEFF.

	It is optionally written in the start of Unicode files to ~~clairify~~ the byte order of the file.		It is optionally written in the start of Unicode files to clarify the byte order of the file.

	{\|{{prettytable}}		{\|{{prettytable}}

Thomas Linder Puls: Initial

2008-02-03T21:46:47Z

Initial

New page

Unicode is an industry standard allowing computers to consistently represent and manipulate text expressed in most of the world's writing systems.

=== Encoding ===

Unicode can be encoded in several ways. In Windows (and thus Visual Prolog) the most interesting formats are UTF-8 and UTF-16 (Little Endian). UTF is an actonym for Unicode Transfer Format. UTF-8 is an 8-bit character set encoding where standard ANSII characters are kept as they are and more rare (in western languages) characters are encoded using two, three or four byte character sequences.

In UTF-16 Little Endian Unicode is encoded using sequences of 1 or 2 16-bit units. UTF-16 is used internally in Windows API calls. Little Endian means that the least signifiant byte of each 16-bit unit is stored before the most significant byte.

=== Byte-order mark ===

A byte-order mark (BOM) is the Unicode character with hex value 0xFEFF.

It is optionally written in the start of Unicode files to clairify the byte order of the file.

{|{{prettytable}}
|-
! Encoding
! Representation (hexadecimal)
|-
| UTF-16 Big Endian
| <tt>FE FF</tt>
|-
| UTF-16 Little Endian
| <tt>FF FE</tt>
|}

It is also optionally written in UTF-8 files to indicate that UTF-8 format is used. In UTF-8 the values are <tt>EF BB BF</tt>. It can also be used in other Unicode transfer.

=== References ===

* [[wikipedia:Unicode]]
* [[wikipedia:UTF-8]]
* [[wikipedia:UTF-16]]
* [[wikipedia:Byte-order mark]]