macro_rules! first_opt
{
($O: expr , $P: pat => $B: expr ) =>
(
for o in $O.iter()
{
match *o
{
$P =>
{
$B
break;
},
_ => ()
};
}
)
}
macro_rules! first_opt_default
{
($O: expr , $P: pat => $B: expr , _ => $E: expr ) =>
(
{
let mut found = false;
for o in $O.iter()
{
match *o
{
$P =>
{
found = true;
$B
break;
},
_ => ()
};
}
if !found
{
$E
}
}
)
}
pub(crate) trait OneWayOwned
{
type Output;
fn to_one_way_owned(&self) -> Self::Output;
}
impl<'l, T: OneWayOwned> OneWayOwned for &'l [T]
{
type Output = Vec<<T as OneWayOwned>::Output>;
fn to_one_way_owned(&self) -> Self::Output
{
self.iter().map(|v| v.to_one_way_owned()).collect()
}
}
pub(crate) fn escape(s: &str) -> String
{
let mut res = String::with_capacity(s.len());
for c in s.chars()
{
match c
{
'\\' => res.push_str(r"\\"),
'\n' => res.push_str(r"\n"),
'\t' => res.push_str(r"\t"),
'"' => res.push_str(r#"\""#),
c => res.push(c),
}
}
res
}
#[test]
fn escape_test()
{
assert_eq!(r"\\", escape(r"\"));
assert_eq!(r"\\\\", escape(r"\\"));
assert_eq!(r#"\\\""#, escape(r#"\""#));
assert_eq!(r#"\"\""#, escape(r#""""#));
assert_eq!(r"\n", escape("\n"));
}