Struct Context 

pub struct Context {

    pub font: FontKey,
    pub math_font: FontKey,
    pub font_size: Length,
    pub leading: Length,
    pub paragraph_width: Length,
    pub paragraph_top: Length,
    pub paragraph_bottom: Length,
    pub manual_rising: Length,
    pub dominant_wide_script: Script,
    pub dominant_narrow_script: Script,
    pub langsys_scheme: [Language; 4],
    pub font_scheme: [ScriptFont; 4],
    pub script_space_map: [[f64; 4]; 4],
    pub text_color: Color,
    pub hyphen_badness: i64,
    pub hyphen_dictionary: Option<HyphenLang>,
    pub left_hyphen_min: i64,
    pub right_hyphen_min: i64,
    pub space_natural: f64,
    pub space_shrink: f64,
    pub space_stretch: f64,
    pub adjacent_stretch: f64,
    pub math_command: Option<MathCmdId>,
    pub code_text_command: Option<MathCmdId>,
    pub math_char_class: MathCharClass,
    pub math_class_map: Arc<BTreeMap<String, (String, MathKind)>>,
    pub math_variant_char_map: Arc<BTreeMap<(char, MathCharClass), char>>,
    pub math_script_level: MathScriptLevel,
    pub math_cramped: bool,
}

The typesetting context (a subset of context_main in horzBox.ml).

Fields

font: FontKey

math_font: FontKey

The dedicated math font (v0.0.6 context_main.math_font; set-math-font). Math layout measures/emits glyphs under THIS key, falling back to font per-glyph when it has no glyph (see primitives::math_glyph_font). The OpenType MATH-table lookups key on this same FontKey.

font_size: Length

leading: Length

Baseline-to-baseline distance.

paragraph_width: Length

Wrap width for paragraphs.

paragraph_top: Length

Extra vertical skip inserted above a paragraph (set-paragraph-margin’s first argument; v0.0.6 context_main.paragraph_top, horzBox.ml:227). Emitted by prim_line_break as a leading VertBox::Skip. A skip at the very top of a page/column is discarded by chop_page (upstream’s page-top glue suppression), so this adds no space above a page’s first paragraph.

paragraph_bottom: Length

Extra vertical skip inserted below a paragraph (set-paragraph-margin’s second argument; v0.0.6 context_main.paragraph_bottom, horzBox.ml:228) — a trailing VertBox::Skip.

manual_rising: Length

A manual vertical shift applied to text set under this context (set-manual-rising’s argument; v0.0.6 context_main.manual_rising, horzBox.ml:232). Stored only: nothing downstream reads it (upstream’s PHGRising box has no analogue here).

dominant_wide_script: Script

set-dominant-wide-script (v0.0.6 context_main.dominant_wide_script, horzBox.ml:218). Storage only; no layout consumer yet.

dominant_narrow_script: Script

set-dominant-narrow-script (horzBox.ml:219). Same status.

langsys_scheme: [Language; 4]

set-language/get-language (v0.0.6 context_main.langsys_scheme, horzBox.ml:216 — a script→language_system map). Stored as a dense 4-slot array indexed by Script’s discriminant; upstream’s “absent from map” IS NoLanguageSystem (get_language_system’s default, horzBox.ml:483-487), so the empty map and [NoLanguageSystem; 4] are indistinguishable — no Option needed.

font_scheme: [ScriptFont; 4]

set-font’s per-script font/ratio/rising scheme (v0.0.6 context_main.font_scheme, horzBox.ml:214), indexed by Script’s discriminant. Resolution rule (back-compat critical, see set-font’s doc in rustyfi-lang): Latin-script text reads Context::font directly, NOT this scheme’s Latin slot — set-font Latin f writes BOTH so the two stay in sync, leaving a bare set-font-key/\bold/\emph (which only touches font) unaffected.

script_space_map: [[f64; 4]; 4]

set-space-ratio-between-scripts (v0.0.6 context_main.script_space_map, horzBox.ml:222) — the space inserted between two adjacent runs of DIFFERENT scripts, as a ratio of font_size. Indexed [left script][right script] by Script’s discriminant, so the map is directional: upstream keys ScriptSpaceMap on the ordered pair and registers the four Latin↔CJK directions separately (primitives.cppo.ml:491-494).

Only the NATURAL ratio is stored, because only it is observable. The primitive takes three (natural, shrink, stretch), and upstream’s ScriptSpaceMap really does hold all three — but pure_space_between_scripts spends them as LBAtom((natural (size *% r0), size *% r1, size *% r2), _), whose first field is metrics = length_info * length * length, i.e. (width info, height, depth). r1 and r2 land in the height and depth slots and never reach the glue’s elasticity; see primitives.rs’s interscript_glue for the full argument. Keeping the two dead ratios here would imply a stretch this glue does not have.

Upstream’s map is SPARSE and a miss falls through to the JLreq class table and then to adjacent_space; this dense array cannot distinguish “absent” from “present and 0.0”. That costs nothing, because the port only ever consults it at a is_latin_cjk_boundary, where upstream’s fall-through is already unreachable — the four Latin↔CJK keys are exactly the ones the default map fills. A 0.0 entry still emits a zero-width glue rather than nothing, keeping the break opportunity upstream’s discretionary_if_breakable wrapper grants regardless of the box’s width.

text_color: Color

set-text-color/get-text-color (row 1-2; v0.0.6 context_main.text_color). Copied into each run’s HorzStringInfo::color at box-construction time — which is what both PDF writers emit their fill-color op from.

hyphen_badness: i64

set-hyphen-penalty (row 3; v0.0.6 context_main.hyphen_badness). Consumed by rustyfi-lang’s flush_word injection as each injected Discretionary’s penalty, but only when hyphen_dictionary is Some(_); with no dictionary installed it has no layout effect.

hyphen_dictionary: Option<HyphenLang>

The installed hyphenation dictionary (set-hyphenation-dictionary/load-hyphenation-dictionary; v0.0.6 context_main.hyphen_dictionary). flush_word (rustyfi-lang) runs the hyphenation branch iff this is Some(tag) and the run’s script is Latin.

left_hyphen_min: i64

Minimum number of chars that must PRECEDE an accepted hyphenation break (set-hyphen-min’s first argument; v0.0.6 context_main.left_hyphen_min). Default 3.

right_hyphen_min: i64

Minimum number of chars that must FOLLOW it (set-hyphen-min’s second argument). Default 2.

space_natural: f64

set-space-ratio’s three fields (row 4; v0.0.6 context_main.space_natural/space_shrink/space_stretch). Each is a ratio of font_size DIRECTLY, not of the natural width: text_to_boxes’s interword glue is natural = font_size * space_natural, shrink/stretch likewise.

space_shrink: f64

space_stretch: f64

adjacent_stretch: f64

set-adjacent-stretch (v0.0.6 context_main.adjacent_stretch) — the stretch, as a ratio of font_size, of the glue SATySFi puts between two DIRECTLY ADJACENT CJK characters (convertText.ml:101 adjacent_space: natural 0, shrink 0, stretch font_size * ratio). This is what lets a Japanese line fill its column: unspaced CJK has no interword glue, so without it a CJK line’s only elasticity is whatever incidental Latin spaces it happens to contain.

math_command: Option<MathCmdId>

The installed [math] inline-cmd applied to bare ${…} in inline text (v0.0.6 context_main.math_command). None only for contexts built by Context::initial directly (unit tests) — the get-initial-context primitive always installs its second argument.

code_text_command: Option<MathCmdId>

set-code-text-command (v0.0.6 context_main.code_text_command) — the [string] inline-cmd a backtick literal inside inline text is handed to. None is upstream’s DefaultCodeTextCommand: the literal is set as ordinary text. Same id-into-Interp handle as math_command.

math_char_class: MathCharClass

\mathrm/\bm/… restyling target (v0.0.6 context_main. math_char_class): which Mathematical- Alphanumeric style block a plain ${…} letter resolves to. Set by Math::ChangeCharClass’s layout arm (primitives.rs), consulted by resolve_variant_char. Defaults to Italic, v0.0.6’s own default.

math_class_map: Arc<BTreeMap<String, (String, MathKind)>>

Upstream default_math_class_map (primitives.cppo.ml:465-480): whole-TOKEN entries (=, -, ,, …) consulted BEFORE the per-char variant lookup below. Arc so that cloning a Context (every ..ctx spread) stays a refcount bump.

math_variant_char_map: Arc<BTreeMap<(char, MathCharClass), char>>

set-math-variant-char’s runtime override table: (source char, style) -> replacement char, consulted BEFORE default_math_variant_char’s built-in Mathematical-Alphanumeric remap. Empty by default; copy-on-written via Arc::make_mut.

math_script_level: MathScriptLevel

V0_1-only (enter_script, port of dev-0-1-0 src/frontend/context.ml:52-68). Base under V0_0 always.

math_cramped: bool

Whether the current math sub-formula is laid out “cramped” (TeXbook Appendix G): set on the recursive layout Context for a radical’s radicand, a fraction’s denominator, and any subscript. Read by BOTH V0_0 and V0_1 (the bit rides the shared layout-recursion clone, not a version-gated primitive). Only consumed by sup_shift_clamped’s superscript shift-up formula.

Implementations

impl Context

pub fn initial(paragraph_width: Length) -> Context

The default context get-initial-context hands to document.

Trait Implementations

impl Clone for Context

fn clone(&self) -> Context

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Context

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

Formats the value using the given formatter.

impl PartialEq for Context

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Context