Struct Syntax 

pub struct Syntax {

    pub code: String,
    pub lexer_name: String,
    pub theme: String,
    pub line_numbers: bool,
    pub start_line: usize,
    pub line_range: Option<(usize, usize)>,
    pub word_wrap: bool,
    pub tab_size: usize,
    pub padding: (usize, usize, usize, usize),
    pub highlight_lines: HashSet<usize>,
    pub background_color: Option<String>,
    pub indent_guides: bool,
    pub code_width: Option<usize>,
    pub dedent: bool,
    pub style_ranges: Vec<(Style, Range<usize>)>,
}

Syntax-highlighted code display.

Renders code with syntax highlighting, optional line numbers, word wrap, theme selection, and more.

Fields

code: String

The source code to highlight.

lexer_name: String

Language name for syntax lookup (e.g., “rust”, “python”, “json”).

theme: String

Theme name (e.g., “base16-ocean.dark”, “base16-mocha.dark”).

line_numbers: bool

Whether to display line numbers.

start_line: usize

Starting line number (default 1).

line_range: Option<(usize, usize)>

Optional (start, end) line range to display (1-based, inclusive).

word_wrap: bool

Whether to wrap long lines.

tab_size: usize

Tab width for tab expansion (default 4).

padding: (usize, usize, usize, usize)

(top, right, bottom, left) padding (top/bottom in blank lines, left/right in spaces inside the code area). Mirrors the CSS shorthand convention used by Padding and matches rich v14.1.0+ Syntax.padding (4-tuple).

Use Self::with_padding / unpack_padding to construct from any shorthand variant: n → (n, n, n, n), (v, h) → (v, h, v, h), (t, h, b) → (t, h, b, h), (t, r, b, l) → as-is.

highlight_lines: HashSet<usize>

Line numbers to highlight with a special background. Stored as a HashSet for O(1) lookup per rendered line.

background_color: Option<String>

Optional override for background color (CSS hex like “#282c34”).

indent_guides: bool

Whether to show indent guides.

code_width: Option<usize>

Fixed width for code area (excluding line numbers), or None for auto.

dedent: bool

Whether to auto-dedent code by stripping common leading whitespace.

style_ranges: Vec<(Style, Range<usize>)>

Style ranges to apply on top of syntax highlighting. Each entry is a (style, character_range) pair applied during rendering.

Implementations

impl Syntax

pub fn new(code: &str, lexer_name: &str) -> Self

Create a new Syntax with defaults: base16-mocha.dark theme (Monokai-like), no line numbers.

pub fn from_path(path: &str) -> Result<Self, SyntaxError>

Create a Syntax by reading a file and auto-detecting the language from its extension.

pub fn with_theme(self, theme: &str) -> Self

Set the theme.

pub fn with_line_numbers(self, line_numbers: bool) -> Self

Enable or disable line numbers.

pub fn with_start_line(self, start: usize) -> Self

Set the starting line number.

pub fn with_line_range(self, range: (usize, usize)) -> Self

Set the line range to display (1-based, inclusive).

pub fn with_word_wrap(self, wrap: bool) -> Self

Enable or disable word wrap.

pub fn with_tab_size(self, size: usize) -> Self

Set the tab size for tab expansion.

pub fn with_highlight_lines( self, lines: impl IntoIterator<Item = usize>, ) -> Self

Set which line numbers to highlight.

Accepts any iterator or Vec; lines are stored in a HashSet for O(1) per-line lookup during rendering.

pub fn with_indent_guides(self, guides: bool) -> Self

Enable or disable indent guides.

pub fn with_code_width(self, width: usize) -> Self

Set a fixed code width.

pub fn with_dedent(self, dedent: bool) -> Self

Enable or disable auto-dedent of common leading whitespace.

pub fn with_padding(self, spec: PaddingSpec) -> Self

Set padding from a PaddingSpec shorthand, expanding to the full (top, right, bottom, left) tuple stored in self.padding.

let s = Syntax::new("fn main() {}", "rs")
    .with_padding(PaddingSpec::VertHoriz(1, 2));
assert_eq!(s.padding, (1, 2, 1, 2));

pub fn stylize_range(&mut self, style: Style, range: Range<usize>)

Add a style to apply over a flat character range of the code.

The range is in terms of character offsets into the original code string (after dedent, if enabled). Multiple ranges may overlap; they are applied in order on top of the syntax highlighting.

pub fn stylize_range_linecol( &mut self, style: Style, start: (usize, usize), end: (usize, usize), )

Add a style to apply over a (line, col) range of the code.

Both start and end are (line, col) pairs where line is 1-based and col is 0-based character offset within the line. The pair is converted to a flat character offset and delegated to stylize_range.

Matches the start=(line, col), end=(line, col) form used by Python rich.

pub fn measure(&self) -> Measurement

Measure the width required to render this Syntax.

Respects line_range when set — only visible lines contribute to the maximum width, matching what render_syntax actually outputs.

Trait Implementations

impl Clone for Syntax

fn clone(&self) -> Syntax

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Syntax

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

Formats the value using the given formatter.

impl Display for Syntax

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

Formats the value using the given formatter.

impl Renderable for Syntax

Implement the Renderable trait so Syntax can be printed by Console.

fn gilt_console( &self, _console: &Console, options: &ConsoleOptions, ) -> Vec<Segment>

Produce segments for rendering on the given console with given options.