Struct syntect::parsing::Scope

pub struct Scope { /* fields omitted */ }

A hierarchy of atoms with semi-standardized names used to accord semantic information to a specific piece of text.

These are generally written with the atoms separated by dots, and - by convention - atoms are all lowercase alphanumeric.

Example scopes: text.plain, punctuation.definition.string.begin.ruby, meta.function.parameters.rust

syntect uses an optimized format for storing these that allows super fast comparison and determining if one scope is a prefix of another. It also always takes 16 bytes of space. It accomplishes this by using a global repository to store string values and using bit-packed 16 bit numbers to represent and compare atoms. Like “atoms” or “symbols” in other languages. This means that while comparing and prefix are fast, extracting a string is relatively slower but ideally should be very rare.

Implementations

impl Scope

pub fn new(s: &str) -> Result<Scope, ParseScopeError>

Parses a Scope from a series of atoms separated by dot (.) characters

Example: Scope::new("meta.rails.controller")

pub fn atom_at(self, index: usize) -> u16

Gets the atom number at a given index.

I can’t think of any reason you’d find this useful. It is used internally for turning a scope back into a string.

pub fn len(self) -> u32

Returns the number of atoms in the scope

pub fn is_empty(&self) -> bool

pub fn build_string(self) -> String

Returns a string representation of this scope

This requires locking a global repo and shouldn’t be done frequently.

pub fn is_prefix_of(self, s: Scope) -> bool

Tests if this scope is a prefix of another scope. Note that the empty scope is always a prefix.

This operation uses bitwise operations and is very fast

Examples

use syntect::parsing::Scope;
assert!( Scope::new("string").unwrap()
        .is_prefix_of(Scope::new("string.quoted").unwrap()));
assert!( Scope::new("string.quoted").unwrap()
        .is_prefix_of(Scope::new("string.quoted").unwrap()));
assert!( Scope::new("").unwrap()
        .is_prefix_of(Scope::new("meta.rails.controller").unwrap()));
assert!(!Scope::new("source.php").unwrap()
        .is_prefix_of(Scope::new("source").unwrap()));
assert!(!Scope::new("source.php").unwrap()
        .is_prefix_of(Scope::new("source.ruby").unwrap()));
assert!(!Scope::new("meta.php").unwrap()
        .is_prefix_of(Scope::new("source.php").unwrap()));
assert!(!Scope::new("meta.php").unwrap()
        .is_prefix_of(Scope::new("source.php.wow").unwrap()));

Trait Implementations

impl Clone for Scope

fn clone(&self) -> Scope

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Scope

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

Formats the value using the given formatter.

impl Default for Scope

fn default() -> Scope

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Scope

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error> where
    D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl Display for Scope

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

Formats the value using the given formatter.

impl FromStr for Scope

type Err = ParseScopeError

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Scope, ParseScopeError>

Parses a string s to return a value of this type.

impl Hash for Scope

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

Feeds this value into the given Hasher.

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

Feeds a slice of this type into the given Hasher.

impl Ord for Scope

fn cmp(&self, other: &Scope) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl PartialEq<Scope> for Scope

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

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

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

This method tests for !=.

impl PartialOrd<Scope> for Scope

fn partial_cmp(&self, other: &Scope) -> 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 Serialize for Scope

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where
    S: Serializer, 

Serialize this value into the given Serde serializer.

impl Copy for Scope

impl Eq for Scope

impl StructuralEq for Scope

impl StructuralPartialEq for Scope