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dictionary

Note
  Dictionaries are only available in the scripts if the application registers the support for them. The syntax for using dictionaries may differ for the application you're working with so consult the application's manual for more details.

The dictionary stores key-value pairs, where the key is a string, and the value can be of any type. Key-value pairs can be added or removed dynamically, making the dictionary a good general purpose container object.

      obj object;
      obj @handle;

      // Initialize with a list
      dictionary dict = {{'one', 1}, {'object', object}, {'handle', @handle}};

      // Examine and access the values through get or set methods ...
      if( dict.exists('one') )
      {
        // get returns true if the stored type is compatible with the requested type
        bool isValid = dict.get('handle', @handle);
        if( isValid )
        {
          dict.delete('object');
          dict.set('value', 1);
        }
      }

Dictionary values can also be accessed or added by using the index operator.

      // Read and modify an integer value
      int val = int(dict['value']);
      dict['value'] = val + 1;

      // Read and modify a handle to an object instance
      @handle = cast<obj>(dict['handle']);
      if( handle is null )
        @dict['handle'] = object;

Dictionaries can also be created and initialized within expressions as anonymous objects.

      // Call a function that expects a dictionary as input and no other overloads
      // In this case it is possible to inform the initialization list without explicitly giving the type
      foo({{'a', 1},{'b', 2}});

      // Call a function where there are multiple overloads expecting different
      // In this case it is necessary to explicitly define the type of the initialization list
      foo2(dictionary = {{'a', 1},{'b', 2}});

Dictionaries of dictionaries are created using anonymous objects as well.

      dictionary d2 = {{'a', dictionary = {{'aa', 1}, {'ab', 2}}},
                       {'b', dictionary = {{'ba', 1}, {'bb', 2}}}};

# Supporting dictionary object and functions

The dictionary object is a reference type, so it's possible to use handles to the dictionary object when passing it around to avoid costly copies.

## Operators

= assignment

The assignment operator performs a shallow copy of the content.

[] index operator

The index operator takes a string for the key, and returns a reference to the value. If the key/value pair doesn't exist it will be inserted with a null value.

## Methods

void set(const string &in key, ? &in value)
void set(const string &in key, int64 &in value)
void set(const string &in key, double &in value)

Sets a key/value pair in the dictionary. If the key already exists, the value will be changed.

bool get(const string &in key, ? &out value) const
bool get(const string &in key, int64 &out value) const
bool get(const string &in key, double &out value) const

Retrieves the value corresponding to the key. The methods return false if the key is not found, and in this case the value will maintain its default value based on the type.

array<string> @getKeys() const

This method returns an array with all of the existing keys in the dictionary. The order of the keys in the array is undefined.

bool exists(const string &in key) const

Returns true if the key exists in the dictionary.

bool delete(const string &in key)

Removes the key and the corresponding value from the dictionary. Returns false if the key wasn't found.

void deleteAll()

Removes all entries in the dictionary.

bool isEmpty() const

Returns true if the dictionary doesn't hold any entries.

uint getSize() const

Returns the number of keys in the dictionary.

# Supporting dictionaryValue object and functions

The dictionaryValue type is how the dictionary object stores the values. When accessing the values through the dictionary index operator a reference to a dictionaryValue is returned.

The dictionaryValue type itself is a value type, i.e. no handles to it can be held, but it can hold handles to other objects as well as values of any type.

## Operators

= assignment

The value assignment operator should be used to copy a value into the dictionaryValue.

@= handle assignment

The handle assignment operator should be used to set the dictionaryValue to refer to an object instance.

cast<type> cast operator

The cast operator is used to dynamically cast the handle held in the dictionaryValue to the desired type. If the dictionaryValue doesn't hold a handle, or the handle is not compatible with the desired type, the cast operator will return a null handle.

type() conversion operator

The conversion operator is used to return a new value of the desired type. If no value conversion is found, an uninitialized value of the desired type is returned.