LeechCraft  0.6.70-13729-g7046a9d2a7
Modular cross-platform feature rich live environment.
lazy.h
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29 
30 #pragma once
31 
32 #include <functional>
33 #include "monadplus.h"
34 
35 namespace LC
36 {
37 namespace Util
38 {
39  template<typename T>
40  using Lazy_t = std::function<T ()>;
41 
42  template<typename T>
43  Lazy_t<T> MakeLazy (const T& t)
44  {
45  return [t] { return t; };
46  }
47 
48  template<typename R, typename F>
49  Lazy_t<R> MakeLazyF (const F& l)
50  {
51  return l;
52  }
53 
54  template<typename T>
55  struct InstanceMonadPlus<Lazy_t<T>, std::enable_if_t<IsMonadPlus<T> ()>>
56  {
57  static Lazy_t<T> Mzero ()
58  {
59  return [] { return Util::Mzero<T> (); };
60  }
61 
62  static Lazy_t<T> Mplus (const Lazy_t<T>& t1, const Lazy_t<T>& t2)
63  {
64  return [=]
65  {
66  const auto rt1 = t1 ();
67  return rt1 != Util::Mzero<T> () ? rt1 : t2 ();
68  };
69  }
70  };
71 }
72 }
STL namespace.
Lazy_t< T > MakeLazy(const T &t)
Definition: lazy.h:43
std::function< T()> Lazy_t
Definition: lazy.h:40
Lazy_t< R > MakeLazyF(const F &l)
Definition: lazy.h:49
Definition: constants.h:35
static Lazy_t< T > Mplus(const Lazy_t< T > &t1, const Lazy_t< T > &t2)
Definition: lazy.h:62