Enum convert_case::Boundary

pub enum Boundary {
    Hyphen,
    Underscore,
    Space,
    UpperLower,
    LowerUpper,
    DigitUpper,
    UpperDigit,
    DigitLower,
    LowerDigit,
    Acronym,
}

A boundary defines how a string is split into words. Some boundaries, Hyphen, Underscore, and Space, consume the character they split on, whereas the other boundaries do not.

The struct offers methods that return Vecs containing useful groups of boundaries. It also contains the list_from method which will generate a list of boundaries based on a string slice.

Note that all boundaries are distinct and do not share functionality. That is, there is no such DigitLetter variant, because that would be equivalent to the current DigitUpper and DigitLower variants. For common functionality, consider using some provided functions that return a list of boundaries.

use convert_case::{Boundary, Case, Casing, Converter};

assert_eq!(
    "transformations_in_3d",
    "TransformationsIn3D"
        .from_case(Case::Camel)
        .without_boundaries(&Boundary::digit_letter())
        .to_case(Case::Snake)
);

let conv = Converter::new()
    .set_boundaries(&Boundary::list_from("aA "))
    .to_case(Case::Title);
assert_eq!("7empest By Tool", conv.convert("7empest byTool"));

Variants

Hyphen

Splits on -, consuming the character on segmentation.

use convert_case::Boundary;
assert_eq!(
    vec![Boundary::Hyphen],
    Boundary::list_from("-")
);

Underscore

Splits on _, consuming the character on segmentation.

use convert_case::Boundary;
assert_eq!(
    vec![Boundary::Underscore],
    Boundary::list_from("_")
);

Space

Splits on space, consuming the character on segmentation.

use convert_case::Boundary;
assert_eq!(
    vec![Boundary::Space],
    Boundary::list_from(" ")
);

UpperLower

Splits where an uppercase letter is followed by a lowercase letter. This is seldom used, and is not included in the defaults.

use convert_case::Boundary;
assert_eq!(
    vec![Boundary::UpperLower],
    Boundary::list_from("Aa")
);

LowerUpper

Splits where a lowercase letter is followed by an uppercase letter.

use convert_case::Boundary;
assert_eq!(
    vec![Boundary::LowerUpper],
    Boundary::list_from("aA")
);

DigitUpper

Splits where digit is followed by an uppercase letter.

use convert_case::Boundary;
assert_eq!(
    vec![Boundary::DigitUpper],
    Boundary::list_from("1A")
);

UpperDigit

Splits where an uppercase letter is followed by a digit.

use convert_case::Boundary;
assert_eq!(
    vec![Boundary::UpperDigit],
    Boundary::list_from("A1")
);

DigitLower

Splits where digit is followed by a lowercase letter.

use convert_case::Boundary;
assert_eq!(
    vec![Boundary::DigitLower],
    Boundary::list_from("1a")
);

LowerDigit

Splits where a lowercase letter is followed by a digit.

use convert_case::Boundary;
assert_eq!(
    vec![Boundary::LowerDigit],
    Boundary::list_from("a1")
);

Acronym

Acronyms are identified by two uppercase letters followed by a lowercase letter. The word boundary is between the two uppercase letters. For example, “HTTPRequest” would have an acronym boundary identified at “PRe” and split into “HTTP” and “Request”.

use convert_case::Boundary;
assert_eq!(
    vec![Boundary::Acronym],
    Boundary::list_from("AAa")
);

Implementations

impl Boundary

pub fn list_from(s: &str) -> Vec<Self>

Returns a list of all boundaries that are identified within the given string. Could be a short of writing out all the boundaries in a list directly. This will not identify boundary UpperLower if it also used as part of Acronym.

If you want to be very explicit and not overlap boundaries, it is recommended to use a colon character.

use convert_case::Boundary;
use Boundary::*;
assert_eq!(
    vec![Hyphen, Space, LowerUpper, UpperDigit, DigitLower],
    Boundary::list_from("aA8a -")
);
assert_eq!(
    vec![Underscore, LowerUpper, DigitUpper, Acronym],
    Boundary::list_from("bD:0B:_:AAa")
);

pub fn defaults() -> Vec<Self>

The default list of boundaries used when Casing::to_case is called directly and in a Converter generated from Converter::new(). This includes all the boundaries except the UpperLower boundary.

use convert_case::Boundary;
use Boundary::*;
assert_eq!(
    vec![
        Underscore, Hyphen, Space, LowerUpper, UpperDigit, 
        DigitUpper, DigitLower, LowerDigit, Acronym,
    ],
    Boundary::defaults()
);

pub fn delims() -> Vec<Self>

Returns the boundaries that split around single characters: Hyphen, Underscore, and Space.

use convert_case::Boundary;
use Boundary::*;
assert_eq!(
    vec![Hyphen, Underscore, Space],
    Boundary::delims()
);

pub fn digits() -> Vec<Self>

Returns the boundaries that involve digits: DigitUpper, DigitLower, UpperDigit, and LowerDigit.

use convert_case::Boundary;
use Boundary::*;
assert_eq!(
    vec![DigitUpper, UpperDigit, DigitLower, LowerDigit],
    Boundary::digits()
);

pub fn letter_digit() -> Vec<Self>

Returns the boundaries that are letters followed by digits: UpperDigit and LowerDigit.

use convert_case::Boundary;
use Boundary::*;
assert_eq!(
    vec![UpperDigit, LowerDigit],
    Boundary::letter_digit()
);

pub fn digit_letter() -> Vec<Self>

Returns the boundaries that are digits followed by letters: DigitUpper and DigitLower.

use convert_case::Boundary;
use Boundary::*;
assert_eq!(
    vec![DigitUpper, DigitLower],
    Boundary::digit_letter()
);

pub fn all() -> Vec<Self>

Returns all boundaries. Note that this includes the UpperLower variant which might be unhelpful. Please look at Boundary::defaults.

use convert_case::Boundary;
use Boundary::*;
assert_eq!(
    vec![
        Hyphen, Underscore, Space, LowerUpper, UpperLower, DigitUpper,
        UpperDigit, DigitLower, LowerDigit, Acronym,
    ],
    Boundary::all()
);

Trait Implementations

impl Clone for Boundary

fn clone(&self) -> Boundary

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Boundary

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq<Boundary> for Boundary

fn eq(&self, other: &Boundary) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl Copy for Boundary

impl Eq for Boundary

impl StructuralEq for Boundary

impl StructuralPartialEq for Boundary