Package com.ericsson.otp.erlang

Class OtpErlangMap

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable
    public class OtpErlangMap
extends OtpErlangObject
    Provides a Java representation of Erlang maps. Maps are created from one or more arbitrary Erlang terms.

    The arity of the map is the number of elements it contains. The keys and values can be retrieved as arrays and the value for a key can be queried.

    See Also:
    Serialized Form

    • Constructor Detail

      • OtpErlangMap

        public OtpErlangMap()
        Create an empty map.

      • OtpErlangMap

        public OtpErlangMap​(OtpErlangObject[] keys,
                    OtpErlangObject[] values)
        Create a map from an array of keys and an array of values.
        Parameters:
        keys - the array of terms to create the map keys from.
        values - the array of terms to create the map values from.
        Throws:
        java.lang.IllegalArgumentException - if any array is empty (null) or contains null elements.

      • OtpErlangMap

        public OtpErlangMap​(OtpErlangObject[] keys,
                    int kstart,
                    int kcount,
                    OtpErlangObject[] values,
                    int vstart,
                    int vcount)
        Create a map from an array of terms.
        Parameters:
        keys - the array of terms to create the map from.
        kstart - the offset of the first key to insert.
        kcount - the number of keys to insert.
        values - the array of values to create the map from.
        vstart - the offset of the first value to insert.
        vcount - the number of values to insert.
        Throws:
        java.lang.IllegalArgumentException - if any array is empty (null) or contains null elements.
        java.lang.IllegalArgumentException - if kcount and vcount differ.

      • OtpErlangMap

        public OtpErlangMap​(OtpInputStream buf)
             throws OtpErlangDecodeException
        Create a map from a stream containing a map encoded in Erlang external format.
        Parameters:
        buf - the stream containing the encoded map.
        Throws:
        OtpErlangDecodeException - if the buffer does not contain a valid external representation of an Erlang map.

    • Method Detail

      • arity

        public int arity()
        Get the arity of the map.
        Returns:
        the number of elements contained in the map.

      • put

        public OtpErlangObject put​(OtpErlangObject key,
                           OtpErlangObject value)
        Put value corresponding to key into the map. For detailed behavior description see Map.put(Object, Object).
        Parameters:
        key - key to associate value with
        value - value to associate with key
        Returns:
        previous value associated with key or null

      • remove

        public OtpErlangObject remove​(OtpErlangObject key)
        removes mapping for the key if present.
        Parameters:
        key - key for which mapping is to be remove
        Returns:
        value associated with key or null

      • get

        public OtpErlangObject get​(OtpErlangObject key)
        Get the specified value from the map.
        Parameters:
        key - the key of the requested value.
        Returns:
        the requested value, of null if key is not a valid key.

      • keys

        public OtpErlangObject[] keys()
        Get all the keys from the map as an array.
        Returns:
        an array containing all of the map's keys.

      • values

        public OtpErlangObject[] values()
        Get all the values from the map as an array.
        Returns:
        an array containing all of the map's values.

      • entrySet

        public java.util.Set<java.util.Map.Entry<OtpErlangObject,​OtpErlangObject>> entrySet()
        make Set view of the map key-value pairs
        Returns:
        a set containing key-value pairs

      • toString

        public java.lang.String toString()
        Get the string representation of the map.
        Specified by:
        toString in class OtpErlangObject
        Returns:
        the string representation of the map.

      • encode

        public void encode​(OtpOutputStream buf)
        Convert this map to the equivalent Erlang external representation.
        Specified by:
        encode in class OtpErlangObject
        Parameters:
        buf - an output stream to which the encoded map should be written.

      • equals

        public boolean equals​(java.lang.Object o)
        Determine if two maps are equal. Maps are equal if they have the same arity and all of the elements are equal.
        Specified by:
        equals in class OtpErlangObject
        Parameters:
        o - the map to compare to.
        Returns:
        true if the maps have the same arity and all the elements are equal.

      • match

        public <T> boolean match​(OtpErlangObject term,
                         T binds)
        Description copied from class: OtpErlangObject
        Perform match operation against given term.
        Overrides:
        match in class OtpErlangObject
        Parameters:
        term - the object to match
        binds - variable bindings
        Returns:
        true if match succeeded