include/AD/generic/ordering.h

   1 //////////////////////////////////////////////////////////////////////////////
   2 // NOTICE:
   3 //
   4 // ADLib, Prop and their related set of tools and documentation are in the
   5 // public domain.   The author(s) of this software reserve no copyrights on
   6 // the source code and any code generated using the tools.  You are encouraged
   7 // to use ADLib and Prop to develop software, in both academic and commercial
   8 // settings, and are free to incorporate any part of ADLib and Prop into
   9 // your programs.
  10 //
  11 // Although you are under no obligation to do so, we strongly recommend that
  12 // you give away all software developed using our tools.
  13 //
  14 // We also ask that credit be given to us when ADLib and/or Prop are used in
  15 // your programs, and that this notice be preserved intact in all the source
  16 // code.
  17 //
  18 // This software is still under development and we welcome any suggestions
  19 // and help from the users.
  20 //
  21 // Allen Leung
  22 // 1994
  23 //////////////////////////////////////////////////////////////////////////////
  24
  25 #ifndef hashing_and_ordering_functions_h
  26 #define hashing_and_ordering_functions_h
  27
  28 #include <string.h>
  29 #include <AD/generic/generic.h>
  30
  31 ////////////////////////////////////////////////////////////////////////////
  32 //  Some default hashing functions
  33 ////////////////////////////////////////////////////////////////////////////
  34 inline unsigned int hash(char c)           { return c; }
  35 inline unsigned int hash(unsigned char c)  { return c; }
  36 inline unsigned int hash(int i)            { return i; }
  37 inline unsigned int hash(unsigned int i)   { return i; }
  38 inline unsigned int hash(short i)          { return i; }
  39 inline unsigned int hash(unsigned short i) { return i; }
  40 inline unsigned int hash(long i)           { return i; }
  41 inline unsigned int hash(unsigned long i)  { return i; }
  42 inline unsigned int hash(float d)          { return (unsigned int)d; }
  43 inline unsigned int hash(double d)         { return (unsigned int)d; }
  44 extern unsigned int hash(const char *);
  45
  46 ////////////////////////////////////////////////////////////////////////////
  47 //  Some default equality functions
  48 ////////////////////////////////////////////////////////////////////////////
  49 inline Bool equal(char i, char j)                     { return i == j; }
  50 inline Bool equal(unsigned char i, unsigned char j)   { return i == j; }
  51 inline Bool equal(short i, short j)                   { return i == j; }
  52 inline Bool equal(unsigned short i, unsigned short j) { return i == j; }
  53 inline Bool equal(int i, int j)                       { return i == j; }
  54 inline Bool equal(unsigned int i, unsigned int j)     { return i == j; }
  55 inline Bool equal(long i, long j)                     { return i == j; }
  56 inline Bool equal(unsigned long i, unsigned long j)   { return i == j; }
  57 inline Bool equal(float a, float b)                   { return a == b; }
  58 inline Bool equal(double a, double b)                 { return a == b; }
  59 inline Bool equal(const char * a, const char * b) { return strcmp(a,b) == 0; }
  60
  61 ////////////////////////////////////////////////////////////////////////////
  62 //  Some default ordering functions
  63 ////////////////////////////////////////////////////////////////////////////
  64 inline Bool less(long i, long j)                   { return i < j; }
  65 inline Bool less(short i, short j)                 { return i < j; }
  66 inline Bool less(int i, int j)                     { return i < j; }
  67 inline Bool less(double a, double b)               { return a < b; }
  68 inline Bool less(const char * a, const char * b)   { return strcmp(a,b) < 0; }
  69 inline Bool lesseq(long i, long j)                 { return i <= j; }
  70 inline Bool lesseq(double a, double b)             { return a <= b; }
  71 inline Bool lesseq(const char * a, const char * b) { return strcmp(a,b) <= 0; }
  72 inline int compare(int i, int j)                   { return i - j; }
  73 inline int compare(short i, short j)               { return i - j; }
  74 inline int compare(long i, long j)                 { return i - j; }
  75 inline int compare(double a, double b)
  76     { return a == b ? 0 : (a > b ? 1 : 0); }
  77 inline int compare(float a, float b)
  78     { return a == b ? 0 : (a > b ? 1 : 0); }
  79 inline int compare(const char * a, const char * b) { return strcmp(a,b); }
  80
  81 ////////////////////////////////////////////////////////////////////////////
  82 //  Constants used by hash table implementations.
  83 ////////////////////////////////////////////////////////////////////////////
  84 #define Cell_unused  0
  85 #define Cell_used    1
  86 #define Cell_deleted 2
  87
  88 /////////////////////////////////////////////////////////////////////////////
  89 // This class represents a linear ordering parameterized by the type.
  90 /////////////////////////////////////////////////////////////////////////////
  91 template <class T>
  92    class Ordering {
  93    public:
  94       Ordering() {}
  95      ~Ordering() {}
  96       int compare(const T&, const T&)        const;  // user defined
  97       Bool less(const T& a, const T& b)      const { return compare(a,b) < 0; }
  98       Bool greater(const T& a, const T& b)   const { return compare(a,b) > 0; }
  99       Bool lesseq(const T& a, const T& b)    const { return compare(a,b) <= 0; }
 100       Bool greatereq(const T& a, const T& b) const { return compare(a,b) >= 0; }
 101    };
 102
 103 /////////////////////////////////////////////////////////////////////////////
 104 //  A macro to generate an ordering.  Inlined to allow multiple definition.
 105 /////////////////////////////////////////////////////////////////////////////
 106 #define MakeOrdering(TYPE, comparison_expression) \
 107    inline int Ordering<TYPE>::compare(const TYPE& a, const TYPE& b) const \
 108    { return (comparison_expression); }
 109
 110 #endif