src/gromacs/utility/keyvaluetreetransform.h

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  35 /*! \libinternal \file
  36  * \brief
  37  * Declares utilities for transforming key-value trees.
  38  *
  39  * \author Teemu Murtola <teemu.murtola@gmail.com>
  40  * \inlibraryapi
  41  * \ingroup module_utility
  42  */
  43 #ifndef GMX_UTILITY_KEYVALUETREETRANSFORM_H
  44 #define GMX_UTILITY_KEYVALUETREETRANSFORM_H
  45
  46 #include <functional>
  47 #include <string>
  48
  49 #include "gromacs/utility/classhelpers.h"
  50 #include "gromacs/utility/variant.h"
  51
  52 namespace gmx
  53 {
  54
  55 class KeyValueTreeObject;
  56 class KeyValueTreeObjectBuilder;
  57
  58 class KeyValueTreeTransformRuleBuilder;
  59
  60 namespace internal
  61 {
  62 class KeyValueTreeTransformerImpl;
  63 }
  64
  65 class IKeyValueTreeTransformRules
  66 {
  67     public:
  68         virtual KeyValueTreeTransformRuleBuilder addRule() = 0;
  69
  70     protected:
  71         ~IKeyValueTreeTransformRules();
  72 };
  73
  74 class KeyValueTreeTransformer
  75 {
  76     public:
  77         KeyValueTreeTransformer();
  78         ~KeyValueTreeTransformer();
  79
  80         IKeyValueTreeTransformRules *rules();
  81
  82         KeyValueTreeObject transform(const KeyValueTreeObject &tree) const;
  83
  84     private:
  85         PrivateImplPointer<internal::KeyValueTreeTransformerImpl> impl_;
  86 };
  87
  88 class KeyValueTreeTransformRuleBuilder
  89 {
  90     public:
  91         class Base
  92         {
  93             protected:
  94                 explicit Base(KeyValueTreeTransformRuleBuilder *builder)
  95                     : builder_(builder)
  96                 {
  97                 }
  98
  99                 KeyValueTreeTransformRuleBuilder *builder_;
 100         };
 101
 102         template <typename FromType, typename ToType>
 103         class ToValue : public Base
 104         {
 105             public:
 106                 explicit ToValue(KeyValueTreeTransformRuleBuilder *builder)
 107                     : Base(builder)
 108                 {
 109                 }
 110
 111                 void transformWith(std::function<ToType(const FromType &)> transform)
 112                 {
 113                     builder_->addTransformToVariant(
 114                             [transform] (const Variant &value)
 115                             {
 116                                 return Variant::create<ToType>(transform(value.cast<FromType>()));
 117                             });
 118                 }
 119         };
 120
 121         template <typename FromType>
 122         class ToObject : public Base
 123         {
 124             public:
 125                 explicit ToObject(KeyValueTreeTransformRuleBuilder *builder)
 126                     : Base(builder)
 127                 {
 128                 }
 129
 130                 void transformWith(std::function<void(KeyValueTreeObjectBuilder *, const FromType &)> transform)
 131                 {
 132                     builder_->addTransformToObject(
 133                             [transform] (KeyValueTreeObjectBuilder *builder, const Variant &value)
 134                             {
 135                                 transform(builder, value.cast<FromType>());
 136                             });
 137                 }
 138         };
 139
 140         template <typename FromType>
 141         class AfterFrom : public Base
 142         {
 143             public:
 144                 explicit AfterFrom(KeyValueTreeTransformRuleBuilder *builder)
 145                     : Base(builder)
 146                 {
 147                 }
 148
 149                 template <typename ToType>
 150                 ToValue<FromType, ToType> to(const std::string &path)
 151                 {
 152                     builder_->setToPath(path);
 153                     return ToValue<FromType, ToType>(builder_);
 154                 }
 155
 156                 ToObject<FromType> toObject(const std::string &path)
 157                 {
 158                     builder_->setToPath(path);
 159                     return ToObject<FromType>(builder_);
 160                 }
 161         };
 162
 163         explicit KeyValueTreeTransformRuleBuilder(internal::KeyValueTreeTransformerImpl *impl);
 164         KeyValueTreeTransformRuleBuilder(KeyValueTreeTransformRuleBuilder &&)            = default;
 165         KeyValueTreeTransformRuleBuilder &operator=(KeyValueTreeTransformRuleBuilder &&) = default;
 166         ~KeyValueTreeTransformRuleBuilder();
 167
 168         template <typename FromType>
 169         AfterFrom<FromType> from(const std::string &path)
 170         {
 171             setFromPath(path);
 172             return AfterFrom<FromType>(this);
 173         }
 174
 175     private:
 176         void setFromPath(const std::string &path);
 177         void setToPath(const std::string &path);
 178         void addTransformToVariant(std::function<Variant(const Variant &)> transform);
 179         void addTransformToObject(std::function<void(KeyValueTreeObjectBuilder *, const Variant &)> transform);
 180
 181         class Data;
 182
 183         internal::KeyValueTreeTransformerImpl *impl_;
 184         std::unique_ptr<Data>                  data_;
 185 };
 186
 187 } // namespace gmx
 188
 189 #endif