Struct ClassDefBuilder 

pub struct ClassDefBuilder { /* private fields */ }

An opinionated builder for ClassDefs.

This ensures that class ids are assigned based on the size of the class.

If you need to know the values assigned to particular classes, call the ClassDefBuilder::build_with_mapping method, which will build the final ClassDef table, and will also return a map from the original class sets to the final assigned class id values.

If you don’t care about this, you can also construct a ClassDef from any iterator over (GlyphId16, u16) tuples, using collect:

let gid1 = GlyphId16::new(1);
let gid2 = GlyphId16::new(2);
let gid3 = GlyphId16::new(2);
let my_class: ClassDef = [(gid1, 2), (gid2, 3), (gid3, 4)].into_iter().collect();

Implementations

impl ClassDefBuilder

pub fn new() -> Self

Create a new ClassDefBuilder.

pub fn new_using_class_0() -> Self

Create a new ClassDefBuilder that will assign glyphs to class 0.

In general, class 0 is a sentinel value returned when a glyph is not assigned to any other class; however in some cases (specifically in GPOS type two lookups) the ClassDef has an accompanying CoverageTable, which means that class 0 can be used, since it is known that the class is only checked if a glyph is known to have some class.

pub fn checked_add(&mut self, cls: IntSet<GlyphId16>) -> bool

Check that this class can be added to this classdef, and add it if so.

returns true if the class is added, and false otherwise.

pub fn build_with_mapping(self) -> (ClassDef, HashMap<IntSet<GlyphId16>, u16>)

Returns a compiled ClassDef, as well as a mapping from our glyph sets to the final class ids.

This sorts the classes, ensuring that larger classes are first.

(This is needed when subsequent structures are ordered based on the final order of class assignments.)

pub fn build(self) -> ClassDef

Build a final ClassDef table.

Trait Implementations

impl Clone for ClassDefBuilder

fn clone(&self) -> ClassDefBuilder

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ClassDefBuilder

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

Formats the value using the given formatter.

impl Default for ClassDefBuilder

fn default() -> ClassDefBuilder

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ClassDefBuilder

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for ClassDefBuilder

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for ClassDefBuilder

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for ClassDefBuilder

impl StructuralPartialEq for ClassDefBuilder