Expand description
Haystacks.
A haystack refers to any linear structure which can be split or sliced into smaller, non-overlapping parts. Examples are strings and vectors.
let haystack: &str = "hello"; // a string slice (`&str`) is a haystack.
let (a, b) = haystack.split_at(4); // it can be split into two strings.
let c = &a[1..3]; // it can be sliced.The minimal haystack which cannot be further sliced is called a codeword. For instance, the codeword of a string would be a UTF-8 sequence. A haystack can therefore be viewed as a consecutive list of codewords.
The boundary between codewords can be addressed using an index. The
numbers 1, 3 and 4 in the snippet above are sample indices of a string. An
index is usually a usize.
An arbitrary number may point outside of a haystack, or in the interior of a codeword. These indices are invalid. A valid index of a certain haystack would only point to the boundaries.
Structs
A span is a haystack coupled with the original range where the haystack is found.
Traits
Linear splittable structure.