Trait StringExt 

pub trait StringExt {
    // Required methods
    fn try_substr<'t>(
        &'t self,
        idx: impl StringIndex,
    ) -> Result<&'t str, &'t str>;
    fn try_substr_back<'t>(
        &'t self,
        idx: impl StringIndex,
    ) -> Result<&'t str, &'t str>;
    fn merge<'t>(&'t self, first: &str, second: &str) -> Option<&'t str>;

    // Provided methods
    fn substr<'t>(&'t self, idx: impl StringIndex) -> &'t str { ... }
    fn substr_back<'t>(&'t self, idx: impl StringIndex) -> &'t str { ... }
}

Extension methods for strings

Required Methods

fn try_substr<'t>(&'t self, idx: impl StringIndex) -> Result<&'t str, &'t str>

Try obtain a substring with a given index or range.

Returns Ok(&str) if the exact substring is found.

Returns Err(&str) if len is bound and less than len chars found.

fn try_substr_back<'t>( &'t self, idx: impl StringIndex, ) -> Result<&'t str, &'t str>

Try obtain a substring with a given index or range in reverse.

Returns Ok(&str) if the exact substring is found.

Returns Err(&str) if len is bound and less than len chars found.

fn merge<'t>(&'t self, first: &str, second: &str) -> Option<&'t str>

Concatenate adjacent substrings.

Returns None if first and second are not adjacent or first and second are not substrings of self.

Examples

Correst usage:

let parent = "foobar";
let foo = &parent[0..3];
let bar = &parent[3..6];
assert_eq!(parent.merge(foo, bar), Some("foobar"));
 
// has to be in the correct order
assert_eq!(parent.merge(bar, foo), None);

Not substrings:

let parent = "foobar";
let foo = "foo";
let bar = "bar";
assert_eq!(parent.merge(foo, bar), None);

Not adjacent:

let parent = "foobar";
let fo = &parent[0..2];
let bar = &parent[3..6];
assert_eq!(parent.merge(fo, bar), None);

Overlapping:

let parent = "foobar";
let foob = &parent[0..4];
let obar = &parent[2..6];
assert_eq!(parent.merge(foob, obar), None);

Provided Methods

fn substr<'t>(&'t self, idx: impl StringIndex) -> &'t str

Obtain a substring with a given index or range.

fn substr_back<'t>(&'t self, idx: impl StringIndex) -> &'t str

Obtain a substring with a given index or range in reverse.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<T> StringExt for T

where T: AsRef<str>,