/doc/cset.html

http://github.com/foodmike/PTypes · HTML · 60 lines · 53 code · 3 blank · 4 comment · 0 complexity · bf2e9cc10c837c591a35073f9587b40b MD5 · raw file 

    

  1. <html><!-- #BeginTemplate "/Templates/tmpl.dwt" --><!-- DW6 -->
    2. 

  2. <head>
    3. 

  3. <!-- #BeginEditable "doctitle" --> 
    4. 

  4. <title>PTypes: cset</title>
    5. 

  5. <!-- #EndEditable --> 
    6. 

  6. <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
    7. 

  7. <link rel="stylesheet" href="styles.css">
    8. 

  8. </head>
    9. 

  9. <body bgcolor="#FFFFFF" leftmargin="40" marginwidth="40">
    10. 

  10. <p><a href="../index.html"><img src="title-21.png" width="253" height="39" alt="C++ Portable Types Library (PTypes) Version 2.1" border="0"></a> 
    11. 

  11. <hr size="1" noshade>
    12. 

  12. <!-- #BeginEditable "body" --> 
    13. 

  13. <p class="hpath"><a href="index.html">Top</a>: <a href="basic.html">Basic types</a>: 
    14. 

  14. cset</p>
    15. 

  15. <ul>
    16. 

  16. <li> 
    17. 

  17. <h5><a href="cset.constructors.html">Constructors</a></h5>
    18. 

  18. </li>
    19. 

  19. <li> 
    20. 

  20. <h5><a href="cset.operators.html">Operators</a></h5>
    21. 

  21. </li>
    22. 

  22. <li> 
    23. 

  23. <h5><a href="cset.manipulation.html">Manipulation</a></h5>
    24. 

  24. </li>
    25. 

  25. </ul>
    26. 

  26. <p>The character set class (<span class="lang">cset</span>) implements Pascal-style 
    27. 

  27. set of integer values from 0 to 255, or set of characters. Unlike Pascal sets, 
    28. 

  28. the range of a <span class="lang">cset</span> cannot be changed and is always 
    29. 

  29. 0 through 255. <span class="lang">Cset</span> class implements various operators 
    30. 

  30. (membership, union, intersection, equality, less than or equal to, etc.) as they 
    31. 

  31. are described in the Pascal language. See <a href="cset.operators.html">Operators</a> 
    32. 

  32. for details.</p>
    33. 

  33. <p><span class="lang">Cset</span> is a packed array of 256 bits, it occupies 32 
    34. 

  34. bytes of static or local memory. Each bit indicates whether the corresponding 
    35. 

  35. character is a member of a given set.</p>
    36. 

  36. <p>Another difference between <span class="lang">cset</span> and Pascal sets is 
    37. 

  37. that since C++ compiler does not have a built-in set constructor like the one 
    38. 

  38. in Pascal (e.g. ['A'..'Z', 'a'..'z']), <span class="lang">cset</span> provides 
    39. 

  39. a simple run-time interpreter instead (see <a href="cset.constructors.html"> Constructors</a>).</p>
    40. 

  40. <p>The <span class="lang">cset</span> class is declared in <a href="include/ptypes.h.html">&lt;ptypes.h&gt;</a>.</p>
    41. 

  41. <p>The example below shows the general usage of character sets.</p>
    42. 

  42. <blockquote> 
    43. 

  43. <pre>cset s = &quot;A-Za-z!&quot;;       <span class="comment">// same as ['A'..'Z', 'a'..'z', '!'] in Pascal</span>
    44. 

  44. 

  45. include(s, '_');      <span class="comment">    // include underscore character</span>
    46. 

  46. include(s, '0', '9'); <span class="comment">    // include all chars from '0' to '9'</span>
    47. 

  47. 

  48. if ('a' &amp; s)          <span class="comment">    // check membership</span>
    49. 

  49.     cout &lt;&lt; &quot;Letter 'a' found in the set! :)\n&quot;;
    50. 

  50. 

  51. const cset letters = &quot;A-Za-z_&quot;;     <span class="comment">// define a set of letters</span>
    52. 

  52. string tok = pin.token(letters);    <span class="comment">// read a token from the input stream</span></pre>
    53. 

  53. </blockquote>
    54. 

  54. <p class="seealso">See also: <a href="cset.constructors.html">Constructors</a>, 
    55. 

  55. <a href="cset.operators.html">Operators</a>, <a href="cset.manipulation.html">Manipulation</a></p>
    56. 

  56. <!-- #EndEditable -->
    57. 

  57. <hr size="1">
    58. 

  58. <a href="../index.html" class="ns">PTypes home</a>
    59. 

  59. </body>
    60. 

  60. <!-- #EndTemplate --></html>
    61.