{"id":23349,"date":"2023-03-30T03:05:16","date_gmt":"2023-03-30T03:05:16","guid":{"rendered":"https:\/\/www.booksofall.com\/ja\/?post_type=product&p=23349"},"modified":"2023-03-30T03:05:16","modified_gmt":"2023-03-30T03:05:16","slug":"programming-with-unicode-documentation","status":"publish","type":"product","link":"https:\/\/www.booksofall.com\/ja\/programming-with-unicode-documentation\/","title":{"rendered":"Programming with Unicode Documentation"},"content":{"rendered":"

Chapter 3 –\u00a0Definitions<\/h2>\n

3.1 Character\u00a0<\/b><\/p>\n

Generic term for a semantic symbol<\/a>. Many possible interpretations exist in the context of encoding. In computing, the most important aspect is that characters can be letters, spaces or control characters which represent the end of a file or can be used to trigger a sound.<\/p>\n

3.2 Glyph\u00a0<\/b><\/p>\n

One or more shapes that may be combined into a grapheme. In Latin<\/a>, a glyph often has 2 variants like \u2018A\u2019 and \u2018a\u2019 and Arabic<\/a> often has four. This term is context dependent and different styles or formats can be considered different glyphs. Most relevant in programming is that diacritic marks (e.g. accents like \u2018 and ^) are also glyphs, which are sometimes represented with another at one point, like the \u00e0 in ISO 8859-1 or as two separate glyphs, so an a and the combining \u2018 (U+0300 and U+0061 combined as U+00E0).<\/p>\n

3.3 Code point\u00a0<\/b><\/p>\n

A code point<\/a> is an unsigned integer<\/a>. The smallest code point is zero. Code points are usually written as hexadecimal, e.g. \u201c0x20AC\u201d (8,364 in decimal).<\/p>\n

3.4 Character set (charset)\u00a0<\/b><\/p>\n

A character set, abbreviated charset, is a mapping between code points and characters. The mapping has a fixed size. For example, most 7 bits encodings have 128 entries, and most 8 bits encodings have 256 entries. The biggest charset is the Unicode Character Set 6.0 with 1,114,112 entries.<\/p>\n

In some charsets, code points are not all contiguous. For example, the cp1252 charset maps code points from 0 though 255, but it has only 251 entries: 0x81, 0x8D, 0x8F, 0x90 and 0x9D code points are not assigned. Examples of the ASCII charset: the digit five (\u201c5\u201d, U+0035) is assigned to the code point 0x35 (53 in decimal), and the uppercase letter \u201cA\u201d (U+0041) to the code point 0x41 (65). The biggest code point depends on the size of the charset. For example, the biggest code point of the ASCII charset is 127 (27 \u2212 1)<\/p>\n

Charset examples:<\/p>\n

\"\"<\/p>\n

3.5 Character string\u00a0<\/b><\/p>\n

A character string<\/a>, or \u201cUnicode string\u201d, is a string where each unit is a character. Depending on the implementation, each character can be any Unicode character, or only characters in the range U+0000\u2014U+FFFF, range called the Basic Multilingual Plane (BMP). There are 3 different implementations of character strings:<\/p>\n