Spongy

A minimal runtime string formatter as a PoC for starship format configuration.

NOTE: The API is not stable and may change any time

Why Spongy?

Most template engines or runtime formatters exists do not allow manipulation on the text inside the braces. Often they use a fixed format {:2d}, or a struct property {user.name}.

As described in starship/starship#624, we would like some formatter that can parse something complex as {segment?style=value}, so it would be great if we can get the text in the curly braces.

The design

Fed with a string Hello, {name}!, the formatter should return

[
  Text ( "Hello, " ),
  Item (
    wrapper: Wrapper::Curly,
    text: "name",
  )
  Text ( "!" ),
]

Usage

use spongy::{Formatter, Wrapper};

let formatted = parse_with("{{greeting}}, {name}!", |item| match item.wrapper {
    Wrapper::Curly => match item.text.as_ref() {
        "name" => Some("world".to_owned()),
        _ => None,
    },
    Wrapper::DoubleCurly => match item.text.as_ref() {
        "greeting" => Some("Hello".to_owned()),
        _ => None,
    },
    _ => None,
});
assert_eq!(formatted, "Hello, world!");