macro_rules! parse_try { ([$n:expr; $input:ident; $m:expr; $T:ty] $e:expr) => { ... }; ([$n:expr; $input:ident; $m:expr; $T:ty] $e:expr => $r:expr) => { ... }; ([$n:expr; $input:ident; $m:expr; $T:ty] $e:expr => $r:expr => || $f:expr) => { ... }; ([$n:expr; $input:ident; $m:expr; $T:ty] $pat:ident@$e:expr => $r:expr) => { ... }; }
Expand description
Runs a parser returning Some if it succeeds or None otherwise.
Take a single parser expression as input. Without additional arguments,
returns the output in Some on success. If called as parse_try!(parse_expr => result_expr), returns result_expr in Some on success. The result of
the parse expression can be pattern-binded as parse_try!(pat@pexpr => rexpr).