Simple Substring Trait

• Simple Substring Trait
  • Install
  • Usage
    • Substring
    • Keep

Install

Add the following line to your Cargo.toml file (under [dependencies]):

string-utility = "0.2"

Usage

Import all Traits

use string_utility::prelude::*;

Substring

use string_utility::prelude::*;

fn main() {
    let some_text = "42Hello, world!".to_string();

    // cut first two chars
    let result = some_text.substring(2..);
    let expected = "Hello, world!";
    assert_eq!(result, expected);

    // extract world string
    let result = some_text.substring(9..=13);
    let expected = "world";
    assert_eq!(result, expected);

    // keep everything up to (including) idx 13
    let result = some_text.substring(..=13);
    let expected = "42Hello, world";
    assert_eq!(result, expected);

    // keep everything up to (excluding) idx 13
    let result = some_text.substring(..13);
    let expected = "42Hello, worl";
    assert_eq!(result, expected);

    // keep everything
    let result = some_text.substring(..);
    let expected = "42Hello, world!";
    assert_eq!(result, expected);

    // get last char
    let result = some_text.substring(some_text.len()-1..);
    let expected = "!";
    assert_eq!(result, expected);

  // get last char
  let result = some_text.substring_len(1); // same as (len - 1)..usize::MAX
  let expected = "!";
  assert_eq!(result, expected);
}

Keep

All functions: trait def

use string_utility::prelude::*;

fn main() {
  let some_text = "some start value, some not-so-start value".to_string();
  
  let result = some_text
          .keep("start".to_string())  // keep(pattern)
          // from the
          .end_of_string()
          // whether to keep the pattern "start"
          .excluding_pattern() 
          // keep everything before the pattern
          .before_pattern()
          // exec
          .to_string();
    let expected = "some start value, some not-so-";
    assert_eq!(result, expected);
}