@spec decode16(String.t()) :: binary()

Decodes the given hex string to a binary. Also accepts hex strings prefixed by "0x" for convenience.

iex> decode16("")
""

iex> decode16("666f6f")
"foo"

iex> decode16("0x666f6f")
"foo"

iex> decode16("0X666f6f")
"foo"

iex> decode16("0X666f6F")
"foo"

@spec empty?(nil) :: true

@spec empty?(String.t()) :: boolean()

Returns true if the given term is nil or an empty string.

iex> empty?(nil)
true

iex> empty?("")
true

iex> empty?("  ")
false

iex> empty?("x")
false

@spec encode16(binary()) :: String.t()

Encodes the given binary to a hex string.

iex> encode16("")
""

iex> encode16("foo")
"666f6f"

@spec pad(binary() | [binary()], integer(), :left | :right) :: binary()

Pads a given binary or list of binaries with null bytes until the given binary reaches the given byte size. direction can be either :left or :right, but defaults to :left.

If count is not a positive integer, the binary is returned unchanged.

iex> pad(<<91, 77>>, 4)
<<0, 0, 91, 77>>

iex> pad(<<91, 77>>, 4, :right)
<<91, 77, 0, 0>>

iex> pad([<<91, 77>>, <<129>>], 4, :right)
[<<91, 77, 0, 0>>, <<129, 0, 0, 0>>]

iex> pad([<<91, 77>>, <<129>>], 0)
[<<91, 77>>, <<129>>]

@spec trim_0x(String.t()) :: String.t()

Trims "0x" off the given string.

iex> trim_0x("")
""

iex> trim_0x("666f6f")
"666f6f"

iex> trim_0x("0x666f6f")
"666f6f"

iex> trim_0x("0X666f6f")
"666f6f"