MODULE CountChars6;
(* =========================================================================  
   Example GPCP .NET Console Program 
 
   Compare the relative efficiency of a CASE statement with an equivalent
   sequence of IF THEN ELSE statements.
   The number of occurrences of different categories of characters in a huge 
   string (1 million characters) is counted using both techniques.
   The processing time of each is measured using .NET timing procedures which 
   have microsecond resolution.
   
   Author : Chris Burrows  
   Created: Jan 2007   
   (c) 2007-2008 CFB Software   
   http://www.cfbsoftware.com/gpcp  
   
   ========================================================================= *)

IMPORT
  Dia := "[System]System.Diagnostics",
  Out,
  CPmain;

CONST
  TestLimit = 1000000;

VAR 
  s: ARRAY TestLimit + 1 OF CHAR;
  i: INTEGER;
  timer: Dia.Stopwatch;
  
PROCEDURE WriteCount(count: INTEGER; IN msg: ARRAY OF CHAR);
BEGIN
  Out.Int(count, 8);
  Out.String(msg);
  Out.Ln()
END WriteCount;

PROCEDURE CountChars1(IN s: ARRAY OF CHAR);
VAR
  i, vowels, letters, capitals, digits, others: INTEGER;
  ch: CHAR;
  timer: Dia.Stopwatch;
BEGIN
  vowels := 0;
  letters := 0;
  capitals := 0;
  digits := 0;
  others := 0;
  timer := Dia.Stopwatch.StartNew();
  FOR i := 0 TO LEN(s$) - 1 DO
    ch := s[i];
    IF (ch >= 'a') & (ch <= 'z') THEN 
      INC(letters); 
      IF (ch = 'a') OR (ch = 'e') OR (ch = 'i') OR (ch = 'o') OR (ch = 'u') THEN
        INC(vowels)
      END
    ELSIF (ch >= 'A') & (ch <= 'Z') THEN 
      INC(letters);
      INC(capitals); 
      IF (ch = 'A') OR (ch = 'E') OR (ch = 'I') OR (ch = 'O') OR (ch = 'U') THEN
        INC(vowels)
      END
    ELSIF (ch >= '0') & (ch <= '9') THEN 
      INC(digits)
    ELSE
      INC(others)
    END
  END;
  Out.String(timer.get_Elapsed().ToString()); Out.Ln();
  WriteCount(letters, ' letters');
  WriteCount(capitals, ' capitals');
  WriteCount(vowels, ' vowels');
  WriteCount(letters - vowels, ' consonants');
  WriteCount(digits, ' digits');
  WriteCount(others, ' others');
  Out.Ln() 
END CountChars1;

PROCEDURE CountChars2(IN s: ARRAY OF CHAR);
VAR
  i, vowels, letters, capitals, digits, others: INTEGER;
  timer: Dia.Stopwatch;
BEGIN
  vowels := 0;
  letters := 0;
  capitals := 0;
  digits := 0;
  others := 0;
  timer := Dia.Stopwatch.StartNew();
  FOR i := 0 TO LEN(s$) - 1 DO
    CASE s[i] OF
    'a', 'e', 'i', 'o', 'u':
      INC(vowels);
      INC(letters) |
    'A', 'E', 'I', 'O', 'U':
      INC(vowels);
      INC(letters);
      INC(capitals) |
    'b'..'d', 'f'..'h', 'j'..'n', 'p'..'t', 'v'..'z':
      INC(letters) |
    'B'..'D', 'F'..'H', 'J'..'N', 'P'..'T', 'V'..'Z':
      INC(letters);
      INC(capitals) |
    '0'..'9':
      INC(digits)
    ELSE
      INC(others)
    END
  END;
  Out.String(timer.get_Elapsed().ToString()); Out.Ln();
  WriteCount(letters, ' letters');
  WriteCount(capitals, ' capitals');
  WriteCount(vowels, ' vowels');
  WriteCount(letters - vowels, ' consonants');
  WriteCount(digits, ' digits');
  WriteCount(others, ' others');
  Out.Ln() 
END CountChars2;

BEGIN
  NEW(timer);
  FOR i := 0 TO TestLimit - 1 DO
    s[i] := CHR(i MOD 255 + 1)
  END;
  s[TestLimit] := 0X;
  CountChars1(s);
  CountChars2(s)
END CountChars6.