Macro nom::escaped_transform

macro_rules! escaped_transform {
    (__impl $i: expr, $normal:ident!(  $($args:tt)* ), $control_char: expr, $transform:ident!(  $($args2:tt)* )) => { ... };
    (__impl_1 $i:expr, $submac1:ident!( $($args:tt)* ), $control_char: expr, $submac2:ident!( $($args2:tt)*) ) => { ... };
    (__impl_1 $i:expr, $submac1:ident!( $($args:tt)* ), $control_char: expr, $g:expr) => { ... };
    ($i:expr, $submac:ident!( $($args:tt)* ), $control_char: expr, $($rest:tt)+) => { ... };
    ($i:expr, $f:expr, $control_char: expr, $($rest:tt)+) => { ... };
}

escaped_transform!(&[T] -> IResult<&[T], &[T]>, T, &[T] -> IResult<&[T], &[T]>) => &[T] -> IResult<&[T], Vec<T>> matches a byte string with escaped characters.

The first argument matches the normal characters (it must not match the control character), the second argument is the control character (like in most languages), the third argument matches the escaped characters and transforms them.

As an example, the chain abc\tdef could be abc def (it also consumes the control character)

WARNING: if you do not use the verbose-errors feature, this combinator will currently fail to build because of a type inference error

Example

fn to_s(i:Vec<u8>) -> String {
  String::from_utf8_lossy(&i).into_owned()
}
 named!(transform < String >,
   map!(
     escaped_transform!(call!(alpha), '\\',
       alt!(
           tag!("\\")       => { |_| &b"\\"[..] }
         | tag!("\"")       => { |_| &b"\""[..] }
         | tag!("n")        => { |_| &b"\n"[..] }
       )
     ), to_s
   )
 );
 assert_eq!(transform(&b"ab\\\"cd"[..]), Ok((&b""[..], String::from("ab\"cd"))));