Iterator extension trait for simple scan.
The author of this crate is not good at English.
Forgive me if the document is hard to read.
This crate provides the IteratorSimpleScanExt trait.
The IteratorSimpleScanExt trait is an extension trait of the Iterator trait,
which implements some methods similar to the scan methods of the Iterator
trait, but more simplified and specialized.
The following is a list of those methods. The sample code on the left shows the
case where those simplified methods are used, and the sample code on the right
shows the case where the same process is implemented with scan method.
| Name | simple version | scan version |
|---|---|---|
| `trace` | ```rust (0..10).trace(0, |s, x| s + x) ``` | ```rust (0..10).scan(0, |s, x| { *s += x; Some(*s) }); ``` |
| `trace2` | ```rust (0..10).trace2(0, |s, x| s + x) ``` | ```rust (0..10).scan(0, |s, x| { let prev = *s; *s += x; Some((prev, *s)) }); ``` |
| `diff` | ```rust (0..10).diff(0, |c, p| c - p) ``` | ```rust (0..10).scan(0, |s, x| { let p = mem::replace(s, x); Some(x - p) }); ``` |
Version 0.2 changes trace2 behavior. In version 0.2, it track previous and
current state. While in version 0.1, it track current state and current input.