Crate estring

Expand description

`EString`

A simple way to parse a string using type annotations.

This package was originally designed for enve

Usage

Basic

use estring::EString;

fn main() -> estring::Result<()> {
    let res: i32 = EString::from("10").parse()?;
    assert_eq!(res, 10);
    Ok(())
}

You can use predefined structs like SepVec if you enable structs feature.

Note: You can use custom types as annotations! Just implement ParseFragment!

use estring::{SepVec, EString};

type PlusVec<T> = SepVec<T, '+'>;
type MulVec<T> = SepVec<T, '*'>;

fn main() -> estring::Result<()> {
    let res = EString::from("10+5*2+3")
        .parse::<PlusVec<MulVec<f32>>>()?
        .iter()
        .map(|m| m.iter().product::<f32>())
        .sum::<f32>();

    assert_eq!(res, 23.0);
    Ok(())
}

You can also use predefined aggregators if you enable aggs feature.

use estring::{Aggregate, EString, Product, SepVec, Sum};

type PlusVec<T> = SepVec<T, '+'>;
type MulVec<T> = SepVec<T, '*'>;

fn main() -> estring::Result<()> {
    let res = EString::from("10+5*2+3")
        .parse::<Sum<PlusVec<Product<MulVec<f32>>>>>()?
        .agg();

    assert_eq!(res, 23.0);
    Ok(())
}