journalmap 0.1.1

Journaling datatypes for easy undo, redo & version control
Documentation 
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[![MIT License](https://img.shields.io/badge/license-MIT-blue.svg)](./LICENSE.txt)
[![Crates.io](https://img.shields.io/crates/v/journalmap)](https://crates.io/crates/journalmap)
[![Documentation](https://docs.rs/journalmap/badge.svg)](https://docs.rs/journalmap)

## Journaling data storage types for easy version control and undo + redo

`journalmap`, which was originally made for my side hustle [Mjolnir](https://blacksheepswe.dev/mjolnir/)
, is a crate meant to provide analog to common data storage types with built-in
journaling, meaning each write transaction is recorded so that you can easily
undo and redo operations. The end user treats these data types like you would a
normal Vec or HashMap, except they can add "tags", basically generic markers
that can be traveled to, to either undo a change, redo a change, or check out a
previous version of the data.

## Example

Below is an example of a JournalVec.
```rust
use journalmap::JournalVec;

fn main() {
   let mut rsvp: JournalVec<&'static str, _> = JournalVec::new();

    // Always add a tag at the start
    rsvp.append_tag("start").unwrap();

    rsvp.push("Sarah");
    rsvp.push("John");
    rsvp.push("Mariah");
    rsvp.insert(1, "Steve");

    rsvp.append_tag("middle").unwrap();

    rsvp.pop();
    rsvp.remove(1);

    rsvp.append_tag("end").unwrap();

     // Now let's reverse it and watch our changes be undone...
    rsvp.reverse_to_next();

    assert_eq!(rsvp.as_slice(), &["Sarah", "Steve", "John", "Mariah"]);

    // We can also redo the changes we've applied
    rsvp.forward_to_tag(&"end");

    assert_eq!(rsvp.as_slice(), &["Sarah", "John"]);

    rsvp.reverse_to_next();

    // Inserting a new entry truncates the future so we can no longer
    // re-do the changes we've undone
    rsvp.push("Omar");
    rsvp.append_tag("end").unwrap();

    assert_eq!(rsvp.as_slice(), &["Sarah", "Steve", "John", "Mariah", "Omar"]);
}
```

## Flags

* `serde` - enables serde-based serialization and deserialization of journals.