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diff --git a/Master/texmf-dist/doc/generic/FAQ-en/html/FAQ-whatenc.html b/Master/texmf-dist/doc/generic/FAQ-en/html/FAQ-whatenc.html deleted file mode 100644 index 6beb24750c6..00000000000 --- a/Master/texmf-dist/doc/generic/FAQ-en/html/FAQ-whatenc.html +++ /dev/null @@ -1,78 +0,0 @@ -<head> -<title>UK TeX FAQ -- question label whatenc</title> -</head><body> -<h3>What are encodings?</h3> -<p/>Let’s start by defining two concepts, the <em>character</em> and the -<em>glyph</em>. -The character is the abstract idea of the ‘atom’ of a -language or other dialogue: so it might be a letter in an alphabetic -language, a syllable in a syllabic language, or an ideogram in an -ideographic language. The glyph is the mark created on screen or -paper which represents a character. Of -course, if reading is to be possible, there must be some agreed -relationship between the glyph and the character, so while the precise -shape of the glyph can be affected by many other factors, such as the -capabilities of the writing medium and the designer’s style, the -essence of the underlying character must be retained. -<p/>Whenever a computer has to represent characters, someone has to define -the relationship between a set of numbers and the characters they -represent. This is the essence of an encoding: it is a mapping -between a set of numbers and a set of things to be represented. -<p/>TeX of course deals in encoded characters all the time: the -characters presented to it in its input are encoded, and it emits -encoded characters in its DVI (or PDF) output. These -encodings have rather different properties. -<p/>The TeX input stream was pretty unruly back in the days when Knuth -first implemented the language. Knuth himself prepared documents on -terminals that produced all sorts of odd characters, and as a result -TeX contains some provision for translating the input encoding to -something regular. Nowadays, -the operating system translates keystrokes into a code appropriate for -the user’s language: the encoding used is often a national or -international standard, though many operating systems use “code -pages” defined by Microsoft. These standards and code pages often -contain characters that can’t appear in the TeX system’s input -stream. Somehow, these characters have to be dealt with — so -an input character like “é” needs to be interpreted by TeX in -a way that that at least mimics the way it interprets “<code>\</code><code>’</code><code>e</code>”. -<p/>The TeX output stream is in a somewhat different situation: -characters in it are to be used to select glyphs from the fonts to be -used. Thus the encoding of the output stream is notionally a font -encoding (though the font in question may be a - - -<a href="FAQ-virtualfonts.html">virtual font</a>). In principle, a -fair bit of what appears in the output stream could be direct -transcription of what arrived in the input, but the output stream -also contains the product of commands in the input, and translations -of the input such as ligatures like -<code>fi</code>. -<p/>Font encodings became a hot topic when the -<a href="FAQ-ECfonts.html">Cork encoding</a> -appeared, because of the possibility of suppressing -<code>\</code><code>accent</code> commands in the output stream (and hence improving the -quality of the hyphenation of text in inflected languages, which is -interrupted by the <code>\</code><code>accent</code> commands — see - -<a href="FAQ-hyphen.html">“how does hyphenation work”</a>). -To take advantage of the diacriticised characters represented in the -fonts, it is necessary to arrange that whenever the -command sequence “<code>\</code><code>’</code><code>e</code>” has been input -(explicitly, or implicitly via the sort of mapping of input mentioned -above), the character that codes the position of the “é” glyph is -used. -<p/>Thus we could have the odd arrangement that the diacriticised character in -the TeX input stream is translated into TeX commands that would -generate something looking like the input character; this sequence of -TeX commands is then translated back again into a single -diacriticised glyph as the output is created. This is in fact -precisely what the LaTeX packages <i>inputenc</i> and -<i>fontenc</i> do, if operated in tandem on (most) characters in -the ISO Latin-1 input encoding and the T1 font encoding. -At first sight, it seems eccentric to have the first package do a thing, and -the second precisely undo it, but it doesn’t always happen that way: -most font encodings can’t match the corresponding input encoding -nearly so well, and the two packages provide the sort of symmetry the -LaTeX system needs. -<p/><p>This question on the Web: <a href="http://www.tex.ac.uk/cgi-bin/texfaq2html?label=whatenc">http://www.tex.ac.uk/cgi-bin/texfaq2html?label=whatenc</a> -</body> |