Struct ParagraphObjective 

pub struct ParagraphObjective {
    pub line_penalty: u64,
    pub fitness_demerit: u64,
    pub double_hyphen_demerit: u64,
    pub final_hyphen_demerit: u64,
    pub max_adjustment_ratio: f64,
    pub min_adjustment_ratio: f64,
    pub widow_demerit: u64,
    pub widow_threshold: usize,
    pub orphan_demerit: u64,
    pub orphan_threshold: usize,
    pub badness_scale: u64,
}

Configuration for the paragraph objective function.

All weight values are in the same “demerit” unit space. Higher values mean stronger penalties. The TeX defaults are provided by Default.

Fields

line_penalty: u64

Base penalty added to every line’s badness before squaring (TeX \linepenalty). Higher values prefer fewer lines. Default: 10 (TeX standard).

fitness_demerit: u64

Additional demerit when consecutive lines have incompatible fitness classes. Default: 100 (TeX \adjdemerits).

double_hyphen_demerit: u64

Additional demerit when two consecutive lines both end with flagged breaks (typically hyphens). Default: 100 (TeX \doublehyphendemerits).

final_hyphen_demerit: u64

Additional demerit when the penultimate line has a flagged break and the last line is short. Default: 100 (TeX \finalhyphendemerits).

max_adjustment_ratio: f64

Maximum allowed adjustment ratio before the line is considered infeasible. Lines looser than this threshold get BADNESS_INF. Default: 2.0 (generous for terminal rendering).

min_adjustment_ratio: f64

Minimum allowed adjustment ratio (negative = compression). Default: -1.0 (allow moderate compression).

widow_demerit: u64

Widow penalty: extra demerit if the last line of a paragraph has fewer than widow_threshold characters. Default: 150.

widow_threshold: usize

Character count below which the last line triggers widow_demerit. Default: 15 (approximately one short word).

orphan_demerit: u64

Orphan penalty: extra demerit if the first line of a paragraph followed by a break has fewer than orphan_threshold characters. Default: 150.

orphan_threshold: usize

Character count below which a first-line break triggers orphan_demerit. Default: 20.

badness_scale: u64

Scale factor for badness computation. Matches TeX convention. Default: 10_000.

Implementations

impl ParagraphObjective

pub fn terminal() -> Self

Preset optimized for terminal rendering where cells are monospaced and compression is not possible (no inter-character stretch).

pub fn typographic() -> Self

Preset for high-quality proportional typography (closest to TeX defaults).

pub fn badness(&self, slack: i64, width: usize) -> Option<u64>

Compute the badness of a line with the given slack and target width.

Badness is (|ratio|^3) * badness_scale where ratio = slack / width. Returns None if the line is infeasible (ratio outside bounds).

pub fn adjustment_ratio(&self, slack: i64, width: usize) -> f64

Compute the adjustment ratio for a line.

pub fn demerits( &self, slack: i64, width: usize, penalty: &BreakPenalty, ) -> Option<u64>

Compute demerits for a single break point.

This is the full TeX demerit formula: demerit = (line_penalty + badness)^2 + penalty^2

For forced breaks (negative penalty), the formula becomes: demerit = (line_penalty + badness)^2 - penalty^2

Returns None if the line is infeasible.

pub fn adjacency_demerits( &self, prev_fitness: FitnessClass, curr_fitness: FitnessClass, prev_flagged: bool, curr_flagged: bool, ) -> u64

Compute adjacency demerits between two consecutive line breaks.

Returns the additional demerit to add when prev and curr are consecutive break points.

pub fn widow_demerits(&self, last_line_chars: usize) -> u64

Check if the last line triggers widow penalty.

A “widow” here means the last line of a paragraph is very short, leaving a visually orphaned fragment.

pub fn orphan_demerits(&self, first_line_chars: usize) -> u64

Check if the first line triggers orphan penalty.

An “orphan” here means the first line before a break is very short.

Trait Implementations

impl Clone for ParagraphObjective

fn clone(&self) -> ParagraphObjective

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ParagraphObjective

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

Formats the value using the given formatter.

impl Default for ParagraphObjective

fn default() -> Self

Returns the “default value” for a type.

impl PartialEq for ParagraphObjective

fn eq(&self, other: &ParagraphObjective) -> 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 Copy for ParagraphObjective

impl StructuralPartialEq for ParagraphObjective