Struct Highlighter 

pub struct Highlighter { /* private fields */ }

Syntax highlighter for code blocks.

Wraps syntect to provide a streaming-friendly API with language aliases and background color override support.

Implementations

impl Highlighter

pub fn new() -> Self

Create a new highlighter with the default theme (base16-ocean.dark).

pub fn with_theme(theme_name: &str) -> Self

Create a highlighter with a specific theme.

Available built-in themes:

• “base16-ocean.dark”
• “base16-ocean.light”
• “base16-eighties.dark”
• “base16-mocha.dark”
• “InspiredGitHub”
• “Solarized (dark)”
• “Solarized (light)”

pub fn syntax_set(&self) -> &SyntaxSet

Get a reference to the syntax set.

pub fn theme_set(&self) -> &ThemeSet

Get a reference to the theme set.

pub fn set_theme(&mut self, theme_name: &str)

Set the current theme.

pub fn theme_name(&self) -> &str

Get the current theme name.

pub fn theme(&self) -> &Theme

Get the current theme.

pub fn set_background(&mut self, color: Option<(u8, u8, u8)>)

Override the background color for highlighted output.

This removes all token background colors and uses the specified color for the entire code block. Pass None to use theme defaults.

Example

use streamdown_syntax::Highlighter;

let mut highlighter = Highlighter::new();
// Set a dark grey background
highlighter.set_background(Some((30, 30, 30)));

pub fn background(&self) -> Option<(u8, u8, u8)>

Get the background override color.

pub fn syntax_for_language(&self, language: &str) -> Option<&SyntaxReference>

Find syntax definition for a language name.

This first checks for common aliases (py→Python, js→JavaScript, etc.) and then falls back to syntect’s built-in matching.

pub fn plain_text(&self) -> &SyntaxReference

Get the plain text syntax (for unknown languages).

pub fn new_highlight_state(&self, language: &str) -> HighlightState<'_>

Create a new highlight state for streaming.

This is the preferred way to do line-by-line highlighting.

pub fn highlight_line_with_state( &self, line: &str, state: &mut HighlightState<'_>, ) -> String

Highlight a single line with streaming state.

This is the preferred method for streaming use cases. It maintains parse state across calls to correctly handle multi-line tokens.

Returns

The highlighted line as an ANSI-escaped string (without trailing newline).

pub fn highlight_block(&self, code: &str, language: &str) -> String

Highlight a complete code block.

This is a convenience method for non-streaming use cases. Each line is highlighted and joined with newlines.

pub fn highlight(&self, code: &str, language: Option<&str>) -> String

Simple highlight method (backward compatible).

Highlights code and returns ANSI-formatted string.

pub fn themes(&self) -> Vec<&str>

List available theme names.

pub fn languages(&self) -> Vec<&str>

List available language names.

pub fn has_theme(&self, name: &str) -> bool

Check if a theme exists.

pub fn has_language(&self, name: &str) -> bool

Check if a language is supported.

Trait Implementations

impl Debug for Highlighter

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

Formats the value using the given formatter.

impl Default for Highlighter

fn default() -> Self

Returns the “default value” for a type.