00001 #include "MusimatTutorial.h" 00002 MusimatTutorialSection(B0129) { 00003 Print("*** B.1.29 Representing Text ***"); 00004 /***************************************************************************** 00005 00006 B.1.29 Representing Text 00007 00008 In order to print text, we use a data type called Character, which consists of the letters of the Roman 00009 alphabet, digits from 0 to 9, and some nonprinting characters like tab, white space, and punctuation. 00010 Characters are written in single quotes: 'a', 'B', 'c', and so on. Punctuation marks include ' ' 00011 (blank), ',' (comma), ';' (semicolon), and '.' (period). We can spell words and sentences by 00012 making lists of characters, for example {'G', 'u', 'i', 'd', 'o'}, but this would be exces- 00013 sively tedious. A shortcut for lists of characters is another data type called String. For example, 00014 *****************************************************************************/ 00015 00016 String c = "Ut queant laxis resonare"; 00017 Print(c); 00018 00019 /***************************************************************************** 00020 This string is equivalent to, and much simpler than, assembling a list of characters. 00021 00022 Computers operate with binary numbers, not alphabetic letters. So we must associate each char- 00023 acter we want to display with a unique binary number. The computer operates only on the binary 00024 numeric values; the display screen connected to the computer knows how to convert binary 00025 numeric values to the corresponding characters for display. 00026 00027 We need a table listing the association between particular binary values and the corresponding 00028 printed characters. This table is called a character set. When a key is pressed on a computer key- 00029 board, the keyboard looks up the corresponding binary number in the character set and sends it 00030 to the computer. The computer forwards the number to the display screen, which also uses 00031 the character set to determine which character to display. Only the keyboard and the screen use the 00032 character set; the computer just stores the corresponding binary numbers. 00033 00034 International standard ISO-10646 defines a Universal Character Set, commonly called Unicode. 00035 To keep things simple, Musimat uses a common subset of Unicode called ASCII (see section B.2). 00036 The built-in Character() function takes an ASCII character code as its argument and returns 00037 the corresponding printable Character. 00038 *****************************************************************************/ 00039 00040 Print(Character(65)); 00041 00042 /***************************************************************************** 00043 prints the character 'A'. The Integer() function can take a printable Character as its argu- 00044 ment and return the corresponding ASCII character code. For example: 00045 *****************************************************************************/ 00046 00047 Print(Integer('A')); 00048 00049 /***************************************************************************** 00050 prints 65. 00051 *****************************************************************************/ 00052 } 00053 00055 /* $Revision: 1.2 $ $Date: 2006/09/05 06:32:26 $ $Author: dgl $ $Name: $ $Id: B0129.cpp,v 1.2 2006/09/05 06:32:26 dgl Exp $ */ 00056 // The Musimat Tutorial � 2006 Gareth Loy 00057 // Derived from Chapter 9 and Appendix B of "Musimathics Vol. 1" � 2006 Gareth Loy 00058 // and published exclusively by The MIT Press. 00059 // This program is released WITHOUT ANY WARRANTY; without even the implied 00060 // warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 00061 // For information on usage and redistribution, and for a DISCLAIMER OF ALL 00062 // WARRANTIES, see the file, "LICENSE.txt," in this distribution. 00063 // "Musimathics" is available here: http://mitpress.mit.edu/catalog/item/default.asp?ttype=2&tid=10916 00064 // Gareth Loy's Musimathics website: http://www.musimathics.com/ 00065 // The Musimat website: http://www.musimat.com/ 00066 // This program is released under the terms of the GNU General Public License 00067 // available here: http://www.gnu.org/licenses/gpl.txt 00068
1.7.2