Struct strcursor::grapheme::Gc

pub struct Gc(_);

A slice of a single Unicode grapheme cluster (GC) (akin to str).

A grapheme cluster is a single visual "unit" in Unicode text, and is composed of at least one Unicode code point, possibly more.

This type is a wrapper around str that enforces the additional invariant that it will always contain exactly one grapheme cluster. This allows some operations (such as extracting the base code point) simpler.

Why Grapheme Clusters?

The simplest example is the distinction between "é" ("Latin Small Letter E with Acute") and "é" ("Latin Small Letter E", "Combining Acute Accent"): the first is one code point, the second is two.

In Rust, the char type is a single code point. As a result, treating it as a "character" is incorrect for the same reason that using u8 is: it excludes many legitimate characters. It can also cause issues whereby naive algorithms may corrupt text by considering components of a grapheme cluster separately. For example, truncating a string to "10 characters" using chars can lead to logical characters being broken apart, potentially changing their meaning.

One inconvenience when dealing with grapheme clusters in Rust is that they are not accurately represented by any type more-so than a regular &str. However, operations that might make sense on an individual character (such as asking whether it is in the ASCII range, or is numeric) don't make sense on a full string. In addition, a &str can be empty or contain more than one grapheme cluster.

Hence, this type guarantees that it always represents exactly one Unicode grapheme cluster.

Methods

impl Gc

fn from_str(s: &str) -> Option<&Gc>

Create a new Gc from the given string slice.

The slice must contain exactly one grapheme cluster. In the event that the input is empty, or contains more than one grapheme cluster, this function will return None.

See: split_from.

unsafe fn from_str_unchecked(s: &str) -> &Gc

Create a new Gc from the given string slice.

This function does not check to ensure the provided slice is a single, valid grapheme cluster.

fn split_from(s: &str) -> Option<(&Gc, &str)>

Try to split a single grapheme cluster from the start of s.

Returns None if the given string was empty.

fn len(&self) -> usize

Returns the length of this grapheme cluster in bytes.

fn has_marks(&self) -> bool

Does this grapheme cluster have additional marks applied to it?

This is true if the cluster is comprised of more than a single code point.

fn as_bytes(&self) -> &[u8]

Converts this to a byte slice.

fn as_str(&self) -> &str

Converts this to a string slice.

fn base_char(&self) -> char

Returns the "base" code point.

That is, this returns the first code point in the cluster.

fn base(&self) -> &Gc

Returns the "base" code point as a grapheme cluster.

This is equivalent to converting this GC into a string slice, then slicing off the bytes that make up the first code point.

fn mark_str(&self) -> &str

Returns the combining marks as a string slice.

The result of this method may be empty, or of arbitrary length.

fn chars(&self) -> Chars

An iterator over the code points of this grapheme cluster.

fn char_indices(&self) -> CharIndices

An iterator over the code points of this grapheme cluster, and their associated byte offsets.

fn bytes(&self) -> Bytes

An iterator over the bytes of this grapheme cluster.

fn to_lowercase(&self) -> ToLowercase

Returns an iterator over the code points in the lower case equivalent of this grapheme cluster.

fn to_uppercase(&self) -> ToUppercase

Returns an iterator over the code points in the upper case equivalent of this grapheme cluster.

Trait Implementations

impl Hash for Gc

fn hash<__H: Hasher>(&self, __arg_0: &mut __H)

Feeds this value into the state given, updating the hasher as necessary.

fn hash_slice<H>(data: &[Self], state: &mut H) where H: Hasher

Feeds a slice of this type into the state provided.

impl PartialOrd for Gc

fn partial_cmp(&self, __arg_0: &Gc) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, __arg_0: &Gc) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, __arg_0: &Gc) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, __arg_0: &Gc) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, __arg_0: &Gc) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Ord for Gc

fn cmp(&self, __arg_0: &Gc) -> Ordering

This method returns an Ordering between self and other.

impl PartialEq for Gc

fn eq(&self, __arg_0: &Gc) -> bool

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

fn ne(&self, __arg_0: &Gc) -> bool

This method tests for !=.

impl Eq for Gc

impl AsRef<str> for Gc

fn as_ref(&self) -> &str

Performs the conversion.

impl AsRef<[u8]> for Gc

fn as_ref(&self) -> &[u8]

Performs the conversion.

impl Debug for Gc

fn fmt(&self, fmt: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Display for Gc

fn fmt(&self, fmt: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<'a> PartialEq<&'a Gc> for Gc

fn eq(&self, other: &&'a Gc) -> 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<'a> PartialEq<Gc> for &'a Gc

fn eq(&self, other: &Gc) -> 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 PartialEq<char> for Gc

fn eq(&self, other: &char) -> 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 PartialEq<str> for Gc

fn eq(&self, other: &str) -> 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<'a> PartialEq<&'a str> for Gc

fn eq(&self, other: &&'a str) -> 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 PartialEq<GcBuf> for Gc

fn eq(&self, other: &GcBuf) -> 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 PartialEq<String> for Gc

fn eq(&self, other: &String) -> 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<'a> PartialEq<Cow<'a, Gc>> for Gc

fn eq(&self, other: &Cow<'a, Gc>) -> 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<'a> PartialEq<char> for &'a Gc

fn eq(&self, other: &char) -> 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<'a> PartialEq<str> for &'a Gc

fn eq(&self, other: &str) -> 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<'a> PartialEq<GcBuf> for &'a Gc

fn eq(&self, other: &GcBuf) -> 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<'a> PartialEq<String> for &'a Gc

fn eq(&self, other: &String) -> 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<'a> PartialEq<Cow<'a, Gc>> for &'a Gc

fn eq(&self, other: &Cow<'a, Gc>) -> 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<'a> PartialOrd<&'a Gc> for Gc

fn partial_cmp(&self, other: &&'a Gc) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a> PartialOrd<Gc> for &'a Gc

fn partial_cmp(&self, other: &Gc) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl PartialOrd<char> for Gc

fn partial_cmp(&self, other: &char) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl PartialOrd<str> for Gc

fn partial_cmp(&self, other: &str) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a> PartialOrd<&'a str> for Gc

fn partial_cmp(&self, other: &&'a str) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl PartialOrd<GcBuf> for Gc

fn partial_cmp(&self, other: &GcBuf) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl PartialOrd<String> for Gc

fn partial_cmp(&self, other: &String) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a> PartialOrd<Cow<'a, Gc>> for Gc

fn partial_cmp(&self, other: &Cow<'a, Gc>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a> PartialOrd<char> for &'a Gc

fn partial_cmp(&self, other: &char) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a> PartialOrd<str> for &'a Gc

fn partial_cmp(&self, other: &str) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a> PartialOrd<GcBuf> for &'a Gc

fn partial_cmp(&self, other: &GcBuf) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a> PartialOrd<String> for &'a Gc

fn partial_cmp(&self, other: &String) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a> PartialOrd<Cow<'a, Gc>> for &'a Gc

fn partial_cmp(&self, other: &Cow<'a, Gc>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl ToOwned for Gc

type Owned = GcBuf

fn to_owned(&self) -> Self::Owned

Creates owned data from borrowed data, usually by cloning.