# letter-sequence

Letter-Sequence is a crate that gives you the ability to create sequences more
complex then simple ordinal digits.

## Features

* Render-binding - limit a sequence by the rendered output
* Render a sequence in uppercase, lowercase, or as numeric.
* Mutate a sequence with another sequence using `+=` and `-=`

An uppercase sequence, unbounded by rendering output
```rust
use letter_sequence::SequenceBuilder;
use std::convert::TryFrom;

let mut seq = SequenceBuilder::try_from("A")
	.unwrap()
	.upper()
	.build()
	.unwrap();
let elem = seq.next().unwrap();
assert_eq!( elem.to_string(), "A" );
let elem = seq.next().unwrap();
assert_eq!( elem.to_string(), "B" );
seq.set(25).unwrap();
let elem = seq.next().unwrap();
assert_eq!( elem.to_string(), "Z" );
let elem = seq.nth(3).unwrap();
assert_eq!( elem.to_string(), "AD" );
let elem = seq.next().unwrap();
assert_eq!( elem.to_string(), "AE" );
```

This time with `.max_render_capacity()` set, and `.lower()` cased
```rust
use letter_sequence::SequenceBuilder;
use std::convert::TryFrom;

let mut seq = SequenceBuilder::try_from("y")
	.unwrap()
	.lower()
	.max_render_capacity(1)
	.build()
	.unwrap();
let elem = seq.next().unwrap();
assert_eq!( elem.to_string(), "y"  );
let elem = seq.next().unwrap();
assert_eq!( elem.to_string(), "z"  );
let elem = seq.next();
assert_eq!( elem, None );
```

Also supports bounded and unbounded numeric sequences
```rust
use letter_sequence::SequenceBuilder;
use std::convert::From;

let mut seq = SequenceBuilder::from(99)
	.numeric()
	.max_render_capacity(3)
	.build()
	.unwrap();
let elem = seq.next().unwrap();
assert_eq!( elem.to_string(), "99" );
let elem = seq.next().unwrap();
assert_eq!( elem.to_string(), "100" );
```