View Source Grizzly.ZWave.Encoding (grizzly v7.0.0)
Utility functions for encoding/decoding common data types.
Summary
Functions
Converts a bit into a boolean.
Converts a boolean into a bit.
Decodes an indexed bitmask.
Decodes a 128-bit binary into an IPv6 address tuple.
Converts an integer value and non-zero precision into a float by dividing the
integer by 10 ^ precision
. If the given precision is zero, the integer is
returned as-is.
Encodes an indexed bitmask.
Encodes an IPv6 address tuple into a 128-bit binary.
Converts a float into a tuple containing an integer representation of the float, the factor of 10 by which the integer must be divided to get the original float, and the number of bytes needed to represent the value as a signed integer.
Types
@type bit() :: 0 | 1
@type bitmask_index_to_value_fun() :: bitmask_index_to_value_fun(term())
@type bitmask_index_to_value_fun(v) :: (index :: non_neg_integer() -> v | nil)
@type bitmask_value_to_index_fun() :: bitmask_value_to_index_fun(term())
@type bitmask_value_to_index_fun(v) :: (v -> non_neg_integer())
Functions
@spec bit_to_bool(0 | 1) :: boolean()
Converts a bit into a boolean.
Examples
iex> bit_to_bool(1)
true
iex> bit_to_bool(0)
false
@spec bool_to_bit(boolean()) :: 0 | 1
Converts a boolean into a bit.
Examples
iex> bool_to_bit(true)
1
iex> bool_to_bit(false)
0
decode_indexed_bitmask(bitmask, value_fun \\ &Function.identity/1)
View Source@spec decode_indexed_bitmask(binary(), bitmask_index_to_value_fun(value_type)) :: [ {value_type, boolean()} ] when value_type: var
Decodes an indexed bitmask.
Examples
iex> decode_indexed_bitmask(<<>>)
[]
iex> decode_indexed_bitmask(<<0b10110001::8>>)
[{0, true}, {1, false}, {2, false}, {3, false}, {4, true}, {5, true}, {6, false}, {7, true}]
@spec decode_ipv6_address(binary()) :: :inet.ip6_address()
Decodes a 128-bit binary into an IPv6 address tuple.
Examples
iex> decode_ipv6_address(<<0xfd00::16, 0xaaaa::16, 0::16, 0::16, 0::16, 0::16, 0::16, 2::16>>)
{0xfd00, 0xaaaa, 0, 0, 0, 0, 0, 2}
@spec decode_zwave_float(integer(), non_neg_integer()) :: number()
Converts an integer value and non-zero precision into a float by dividing the
integer by 10 ^ precision
. If the given precision is zero, the integer is
returned as-is.
Examples
iex> decode_zwave_float(0, 0)
0
iex> decode_zwave_float(0, 2)
0.0
iex> decode_zwave_float(1234, 2)
12.34
iex> decode_zwave_float(1234, 1)
123.4
iex> decode_zwave_float(1234, 0)
1234
iex> decode_zwave_float(-1234, 2)
-12.34
encode_indexed_bitmask(values, index_fun \\ &Function.identity/1, opts \\ [])
View SourceEncodes an indexed bitmask.
Examples
iex> encode_indexed_bitmask([])
<<>>
iex> encode_indexed_bitmask(
...> [{0, true}, {4, true}, {5, true}, {6, false}, {7, true}, {8, true}]
...> )
<<0b10110001::8, 0b00000001::8>>
iex> encode_indexed_bitmask(
...> [{0, true}, {4, true}, {5, true}, {6, false}, {7, true}, {8, true}, {31, true}]
...> )
<<0b10110001, 0b00000001, 0b00000000, 0b10000000>>
@spec encode_ipv6_address(:inet.ip6_address()) :: binary()
Encodes an IPv6 address tuple into a 128-bit binary.
Examples
iex> encode_ipv6_address({0xfd00, 0xaaaa, 0, 0, 0, 0, 0, 2})
<<0xfd00::16, 0xaaaa::16, 0::16, 0::16, 0::16, 0::16, 0::16, 2::16>>
@spec encode_zwave_float(value :: number()) :: {int_value :: integer(), precision :: non_neg_integer(), size :: integer()}
Converts a float into a tuple containing an integer representation of the float, the factor of 10 by which the integer must be divided to get the original float, and the number of bytes needed to represent the value as a signed integer.
Examples
iex> encode_zwave_float(0)
{0, 0, 1}
iex> encode_zwave_float(-1.5)
{-15, 1, 1}
iex> encode_zwave_float(-1.50)
{-15, 1, 1}
iex> encode_zwave_float(128)
{128, 0, 2}
iex> encode_zwave_float(127.5)
{1275, 1, 2}
iex> encode_zwave_float(-75.25)
{-7525, 2, 2}
iex> encode_zwave_float(-752.55)
{-75255, 2, 4}
iex> encode_zwave_float(-75.255)
{-75255, 3, 4}