Spanley

This is a generic string span library,
it is meant for use with tokenizing
applications or the likes.

Serde support and API changes
are coming soon.

Please do look into string interners
before deciding to use this crate
to make sure this actually fits your
use case.
String interning features may also
get added on later to this project, but that
is a much later spot on the roadmap.

Example

Input

use spanley::Span;

let message = "\
  This is my generic string span, his name is Spanley.\n\
  Say hi Spanley!\
";

let spanley = Span::new(message, 57, 11).unwrap();

println!("{}", spanley);

Output

hi Spanley!

Features

location

Adds the SpanLocation struct,
accessible through spanley::SpanLocation
or simply by calling one of the related
methods from spanley::Span directly.

SpanLocation gets the line and offset,
for possible logging applications.

Example

Input

use spanley::Span;

let message = "\
  This is my generic string span, his name is Spanley.\n\
  Say hi Spanley!\
";

let spanley = Span::new(message, 57, 11).unwrap();
let location = spanley.get_start_location();

println!("{}", location);

Output

1:4

location-column

This can only be compiled in conjecture with
the location feature flag set to true.

Adds one relatively large extra dependencies,
unicode-width.

This adds additional fields on the
SpanLocation struct;
column_offset and
column_cjk_offset,
which are calculated by the
unicode-width crate.

column_offset is then used instead
of char_offset in the Display
implementation for SpanLocation.

Example

Input

use spanley::Span;

let source = "👩‍👩‍👦‍👦👩‍👩‍👦‍👦👩‍👩‍👦‍👦";

// Additional context:
//
// '👩‍👩‍👦‍👦' spans 7 characters behind
// the scenes and 2 columns on a TUI.
// Hence, inputs divisible by 7 and
// Outputs divisible by 2.

let spanley = Span::new(source, 14, 7).unwrap();
let location = spanley.get_start_location();

println!("{}", location.column_offset());
println!("{}", location);

Output

4
0:4

container

Adds SpanContainer.

SpanContainer simplay associates a
Span to an instance of type T.

This is best used as a way to construct
or otherwise handle tokens or other
types where it is contextually relevant
to associate it with a Span.

Example

Input

use spanley::{Span, SpanContainer};

enum TokenKind {
  Hello,
  World
}

const source: &str = "Hello World!";

let hello_span = Span::new(source, 0, 5).unwrap(); // Hello
let world_span = Span::new(source, 6, 5).unwrap(); // World

let hello = SpanContainer::new(hello_span, TokenKind::Hello);
let world = SpanContainer::new(world_span, TokenKind::World);