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rowtype-yoga/purescript-native/runtime/purescript.h
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1///////////////////////////////////////////////////////////////////////////////
2//
3// Module : purescript.h
4// Copyright : (c) Andy Arvanitis 2018
5// License : BSD
6//
7// Maintainer : Andy Arvanitis
8// Stability : experimental
9// Portability :
10//
11// Basic types and functions to support purescript-to-C++ rendering
12//
13///////////////////////////////////////////////////////////////////////////////
14//
15#ifndef purescript_H
16#define purescript_H
18#include <memory>
19#include <functional>
20#include <deque>
21#include <map>
22#include <string>
24#include <iostream>
26namespace purescript {
28 using std::string;
30 class boxed : public std::shared_ptr<void> {
32 public:
33 using fn_t = std::function<boxed(const boxed&)>;
34 using eff_fn_t = std::function<boxed(void)>;
35 using dict_t = std::map<const string, boxed>;
36 using array_t = std::deque<boxed>;
38 public:
39 using std::shared_ptr<void>::shared_ptr;
41 boxed(const int n) : std::shared_ptr<void>(std::make_shared<int>(n)) {
42 }
44 boxed(const long n) : std::shared_ptr<void>(std::make_shared<int>(static_cast<int>(n))) {
45#ifndef NDEBUG
46 if (n < std::numeric_limits<int>::min() || n > std::numeric_limits<int>::max()) {
47 throw std::runtime_error("integer out of range");
48 }
49#endif // !NDEBUG
50 }
52 boxed(const double n) : std::shared_ptr<void>(std::make_shared<double>(n)) {
53 }
55 boxed(const bool b) : std::shared_ptr<void>(std::make_shared<bool>(b)) {
56 }
58 boxed(const char s[]) : std::shared_ptr<void>(std::make_shared<string>(s)) {
59 }
61 boxed(string&& s) : std::shared_ptr<void>(std::make_shared<string>(std::move(s))) {
62 }
64 boxed(const std::nullptr_t) : std::shared_ptr<void>() {
65 }
67 boxed(array_t&& l) : std::shared_ptr<void>(std::make_shared<array_t>(std::move(l))) {
68 }
70 boxed(dict_t&& m) : std::shared_ptr<void>(std::make_shared<dict_t>(std::move(m))) {
71 }
73 template <typename T,
74 typename = typename std::enable_if<!std::is_same<boxed,T>::value>::type>
75 boxed(const T& f,
76 typename std::enable_if<std::is_assignable<std::function<boxed(boxed)>,T>::value>::type* = 0) : std::shared_ptr<void>(std::make_shared<fn_t>(f)) {
77 }
79 template <typename T,
80 typename = typename std::enable_if<!std::is_same<boxed,T>::value>::type>
81 boxed(const T& f,
82 typename std::enable_if<std::is_assignable<std::function<boxed(void)>,T>::value>::type* = 0) : std::shared_ptr<void>(std::make_shared<eff_fn_t>(f)) {
83 }
85 template <typename T,
86 typename = typename std::enable_if<!std::is_same<boxed,T>::value &&
87 std::is_convertible<T,fn_t>::value>::type>
88 auto operator=(const T& right) -> boxed& {
89 if (std::shared_ptr<void>::operator bool()) {
90 auto& f = *static_cast<fn_t*>(get());
91 f = right;
92 } else {
93 reset(new fn_t(right));
94 }
95 return *this;
96 }
98 auto operator()(const boxed& arg) const -> boxed {
99 auto& f = *static_cast<fn_t*>(get());
100 return f(arg);
101 }
103 auto operator()() const -> boxed {
104 auto& f = *static_cast<eff_fn_t*>(get());
105 return f();
106 }
108 auto operator[](const string& key) const -> const boxed& {
109 const auto& dict = *static_cast<const dict_t*>(get());
110 return dict.at(key);
111 }
113 auto operator[](const string& key) -> boxed& {
114 auto& dict = *static_cast<dict_t*>(get());
115 return dict[key];
116 }
118#ifdef NDEBUG
119 auto operator[](const int index) const -> const boxed& {
120 const auto& array = *static_cast<const array_t*>(get());
121 return array[index];
122 }
124 auto operator[](const int index) -> boxed& {
125 auto& array = *static_cast<array_t*>(get());
126 return array[index];
127 }
128#else
129 auto operator[](const int index) const -> const boxed& {
130 const auto& array = *static_cast<const array_t*>(get());
131 return array.at(index);
132 }
134 auto operator[](const int index) -> boxed& {
135 auto& array = *static_cast<array_t*>(get());
136 return array.at(index);
137 }
139#endif // NDEBUG
141 }; // class boxed
143 template <typename T, typename... Args>
144 inline auto box(Args&&... args) -> boxed {
145 return std::make_shared<T>(std::forward<Args>(args)...);
146 }
148 template <typename T>
149 inline auto unbox(const boxed& b) -> const T& {
150 const auto& unboxed = *static_cast<const T*>(b.get());
151 return unboxed;
152 }
154 template <typename T,
155 typename = typename std::enable_if<!std::is_same<T, const boxed&>::value>::type>
156 constexpr auto unbox(const T value) -> T {
157 return value;
158 }
160 template <typename T>
161 inline auto peek(boxed& b) -> T& {
162 auto& unboxed = *static_cast<T*>(b.get());
163 return unboxed;
164 }
166 template <typename T>
167 inline auto copy(const boxed& b) -> boxed {
168 return box<T>(unbox<T>(b));
169 }
171 using fn_t = boxed::fn_t;
172 using eff_fn_t = boxed::eff_fn_t;
173 using dict_t = boxed::dict_t;
174 using array_t = boxed::array_t;
176 constexpr auto undefined = nullptr;
178} // namespace purescript
180#define FOREIGN_BEGIN(NS) namespace NS {\
181 using namespace purescript;\
182 auto ＿foreign＿() -> dict_t&;\
183 static const auto& NS ## ＿foreign_init = []() {\
184 dict_t& exports = ＿foreign＿();
185#define FOREIGN_END return exports; }(); }
187#endif // purescript_H