include/jitcs_adt_range.h

   1 //===-- jitcs_adt_slice.h ---------------------------------------*- C++ -*-===//
   2 //
   3 //
   4 //===----------------------------------------------------------------------===//
   5
   6 #ifndef _JITCS_ADT_RANGE_H_
   7 #define _JITCS_ADT_RANGE_H_
   8
   9 #include "jitcs_base.h"
  10 #include "jitcs_typefuncs.h"
  11
  12 namespace jitcs {
  13 // simple range for array-like slices
  14 // instead of keeping a size around, it is only using
  15 // a start and end pointer, decreasing the number of
  16 // changed memory positions per traversal step
  17 // size calculation is more costly though
  18
  19   template <typename T> struct OpDerefType {
  20     typedef typename T::value_type value_type;
  21   };
  22   template <typename T> struct OpDerefType<T*> {
  23     typedef T value_type;
  24   };
  25
  26
  27   template <typename T>
  28   struct Range {
  29   public:
  30     typedef typename OpDerefType<T>::value_type value_type;
  31   public:
  32     T itStart;
  33     T itEnd;
  34
  35   public:
  36     Range() = delete;
  37     Range(const Range&) = default;
  38     Range& operator =(const Range&) = default;
  39
  40     Range(T start, T end) : itStart(start), itEnd(end) {}
  41
  42   public:
  43     // range interface
  44     bool isEmpty() const { return itStart == itEnd; }
  45
  46     value_type& getFront()             { _JITCS_DBG_CHECK_(!isEmpty()); return *itStart; }
  47     value_type const& getFront() const { _JITCS_DBG_CHECK_(!isEmpty()); return *itStart; }
  48     value_type& getBack()              { _JITCS_DBG_CHECK_(!isEmpty()); T it = itEnd; --it; return *it; }
  49     value_type const& getBack() const  { _JITCS_DBG_CHECK_(!isEmpty()); T it = itEnd; --it; return *it; }
  50
  51     void popFront() { _JITCS_DBG_CHECK_(!isEmpty()); ++itStart; }
  52     void popBack()  { _JITCS_DBG_CHECK_(!isEmpty()); --itEnd; }
  53
  54     bool operator !() const              { return isEmpty(); }
  55     value_type& operator *()             { return getFront(); }
  56     value_type const& operator *() const { return getFront(); }
  57     value_type* operator ->()             { return &getFront(); }
  58     value_type const* operator ->() const { return &getFront(); }
  59     void operator ++()                   { popFront(); }
  60   };
  61
  62   template <typename T>
  63   struct ConstRange {
  64   public:
  65     typedef typename OpDerefType<T>::value_type value_type;
  66   public:
  67     T itStart;
  68     T itEnd;
  69
  70   public:
  71     ConstRange() = delete;
  72     ConstRange(const ConstRange&) = default;
  73     ConstRange& operator =(const ConstRange&) = default;
  74
  75     ConstRange(T start, T end)
  76       : itStart(start)
  77       , itEnd(end) {
  78     }
  79
  80   public:
  81     // range interface
  82     bool isEmpty() const { return itStart == itEnd; }
  83
  84     value_type const& getFront() const { _JITCS_DBG_CHECK_(!isEmpty()); return *itStart; }
  85     value_type const& getBack() const  { _JITCS_DBG_CHECK_(!isEmpty()); T it = itEnd; --it; return *it; }
  86
  87     void popFront() { _JITCS_DBG_CHECK_(!isEmpty()); ++itStart; }
  88     void popBack()  { _JITCS_DBG_CHECK_(!isEmpty()); --itEnd; }
  89
  90     bool operator !() const              { return isEmpty(); }
  91     value_type const& operator *() const { return getFront(); }
  92     value_type const* operator ->() const { return &getFront(); }
  93     void operator ++()                   { popFront(); }
  94   };
  95
  96   template <typename U>
  97   inline Range<typename U::const_iterator> getRange(U const& u) {
  98     return Range<typename U::const_iterator>(u.begin(), u.end());
  99   }
 100   template <typename U>
 101   inline ConstRange<typename U::const_iterator> getConstRange(U const& u) {
 102     return ConstRange<typename U::const_iterator>(u.begin(), u.end());
 103   }
 104   template <typename U>
 105   inline Range<typename U::iterator> getRange(U& u) {
 106     return Range<typename U::iterator>(u.begin(), u.end());
 107   }
 108 } // end of namespace jitcs
 109
 110 #endif
 111 // _JITCS_ADT_RANGE_H_