Struct PageGraphSignature 

pub struct PageGraphSignature(Vec<PageBoundarySignature>);

The ordered per-page boundary signatures of a whole PageGraph.

Comparing two graph signatures answers both “did pagination change?” (inequality) and “where?” (first_divergence).

Examples

use mos_layout::{LayoutEngine, PageGraphSignature};
use mos_core::Document;
use std::path::PathBuf;

let doc = Document::new(PathBuf::from("doc.mos"));
let result = LayoutEngine::new().layout(&doc);
let signature = PageGraphSignature::of_graph(&result.graph);
// An unchanged layout signs identically and diverges nowhere.
assert_eq!(signature, PageGraphSignature::of_graph(&result.graph));
assert_eq!(signature.first_divergence(&signature), None);

Tuple Fields

0: Vec<PageBoundarySignature>

Implementations

impl PageGraphSignature

pub fn of_graph(graph: &PageGraph) -> Self

Sign every page of graph, in page order.

pub fn pages(&self) -> &[PageBoundarySignature]

The per-page signatures, in page order.

pub fn first_divergence(&self, other: &Self) -> Option<usize>

The index of the first page whose signature differs from other, or None if the two are identical.

When one graph is a prefix of the other (a page was added or removed at the end), the divergence is the length of the shorter graph; the first page index that exists in one but not the other.

Examples

use mos_layout::PageGraphSignature;

let empty = PageGraphSignature::default();
assert_eq!(empty.first_divergence(&empty), None);

Trait Implementations

impl Clone for PageGraphSignature

fn clone(&self) -> PageGraphSignature

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PageGraphSignature

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

Formats the value using the given formatter.

impl Default for PageGraphSignature

fn default() -> PageGraphSignature

Returns the “default value” for a type.

impl Hash for PageGraphSignature

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for PageGraphSignature

fn eq(&self, other: &PageGraphSignature) -> 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 Eq for PageGraphSignature

impl StructuralPartialEq for PageGraphSignature