Crate parlance 

Fundamental text property types.

This crate is intended as a lightweight, no_std-friendly vocabulary layer that can be shared across style systems, text layout engines, and font tooling. It focuses on small, typed representations of common “leaf” concepts (weights, widths, OpenType tags, language tags, etc).

Features

• std (enabled by default): This is currently unused and is provided for forward compatibility.
• bytemuck: Implement traits from bytemuck on GenericFamily.

Example

use parlance::{Language, Tag};

let tag = Tag::parse("wght").unwrap();
assert_eq!(tag.to_bytes(), *b"wght");

let lang = Language::parse("zh-Hans-CN").unwrap();
assert_eq!(lang.as_str(), "zh-Hans-CN");
assert_eq!(lang.language(), "zh");
assert_eq!(lang.script(), Some("Hans"));
assert_eq!(lang.region(), Some("CN"));

Structs

FontFeature

OpenType font feature setting (tag + u16 value).

FontVariation

OpenType font variation setting (tag + f32 value).

FontWeight

Visual weight class of a font, typically on a scale from 1.0 to 1000.0.

FontWidth

Visual width of a font — a relative change from the normal aspect ratio, typically in the range 0.5 to 2.0.

Language

A compact, zero-allocation language tag.

ParseFontFamilyError

Error returned when parsing CSS font-family strings.

ParseSettingsError

Error returned when parsing OpenType settings source strings.

Script

An ISO 15924 script identifier (four ASCII letters).

Tag

A 4-byte OpenType tag (for example wght, liga).

Enums

BaseDirection

The paragraph’s base direction.

BidiControl

An inline bidirectional text control.

BidiDirection

Direction choice used by bidi controls.

BidiOverride

Direction choice used by bidi overrides.

FontFamily

CSS font-family property value.

FontFamilyName

A single named or generic font family.

FontStyle

Visual style or “slope” of a font.

GenericFamily

Generic font families, named after CSS.

OverflowWrap

Control over “emergency” line-breaking.

ParseFontFamilyErrorKind

Kinds of errors that can occur when parsing CSS font-family strings.

ParseLanguageError

An error returned when parsing a Language fails.

ParseScriptError

An error returned from parsing a Script.

ParseSettingsErrorKind

Kinds of errors that can occur when parsing OpenType settings source strings.

TextWrapMode

Control over non-“emergency” line-breaking.

WordBreak

Control over word breaking, named for the CSS property.