pub trait Index: Sealed { }Expand description
A type that can be used to index into a lexpr::Value.
The get method of Value accept any type that implements
Index, as does the square-bracket indexing operator. This
trait is implemented for strings and Value, both of which can be
used to index into association lists, and for usize which is
used to index into to lists by element index.
Note that improper lists are only indexable by usize, not by
strings.
This trait is sealed and cannot be implemented for types outside
of lexpr.
Examples
let data = sexp!(((foo 42) (bar . (1 2 3))));
// Data is an association list so it can be indexed with a string.
let bar = &data["bar"];
// Bar is a list so it can be indexed with an integer.
let second = &bar[1];
assert_eq!(second, 2);