Macro.unescape_string
unescape_string
, go back to Macro module for more information.
Specs
Unescapes the given chars.
This is the unescaping behaviour used by default in Elixir
single- and double-quoted strings. Check unescape_string/2
for information on how to customize the escaping map.
In this setup, Elixir will escape the following: \0
, \a
, \b
,
\d
, \e
, \f
, \n
, \r
, \s
, \t
and \v
. Bytes can be
given as hexadecimals via \xNN
and Unicode code points as
\uNNNN
escapes.
This function is commonly used on sigil implementations
(like ~r
, ~s
and others) which receive a raw, unescaped
string.
Examples
iex> Macro.unescape_string("example\\n")
"example\n"
In the example above, we pass a string with \n
escaped
and return a version with it unescaped.
Specs
unescape_string(String.t(), (non_neg_integer() -> non_neg_integer() | false)) :: String.t()
Unescapes the given chars according to the map given.
Check unescape_string/1
if you want to use the same map
as Elixir single- and double-quoted strings.
Map
The map must be a function. The function receives an integer representing the code point of the character it wants to unescape. Here is the default mapping function implemented by Elixir:
def unescape_map(:newline), do: true
def unescape_map(:unicode), do: true
def unescape_map(:hex), do: true
def unescape_map(?0), do: ?0
def unescape_map(?a), do: ?\a
def unescape_map(?b), do: ?\b
def unescape_map(?d), do: ?\d
def unescape_map(?e), do: ?\e
def unescape_map(?f), do: ?\f
def unescape_map(?n), do: ?\n
def unescape_map(?r), do: ?\r
def unescape_map(?s), do: ?\s
def unescape_map(?t), do: ?\t
def unescape_map(?v), do: ?\v
def unescape_map(e), do: e
If the unescape_map/1
function returns false
, the char is
not escaped and the backslash is kept in the string.
Newlines, Unicode, and hexadecimals code points will be escaped if
the map returns true
respectively for :newline
, :unicode
, and
:hex
.
Examples
Using the unescape_map/1
function defined above is easy:
Macro.unescape_string("example\\n", &unescape_map(&1))