Struct rustc_mir_build::thir::pattern::usefulness::Matrix

pub(super) struct Matrix<'p, 'tcx> {
    patterns: Vec<PatStack<'p, 'tcx>>,
}

A 2D matrix.

Fields

patterns: Vec<PatStack<'p, 'tcx>>

Implementations

impl<'p, 'tcx> Matrix<'p, 'tcx>

fn empty() -> Self

pub(super) fn column_count(&self) -> Option<usize>

Number of columns of this matrix. None is the matrix is empty.

fn push(&mut self, row: PatStack<'p, 'tcx>)

Pushes a new row to the matrix. If the row starts with an or-pattern, this recursively expands it.

fn heads<'a>(&'a self) -> impl Iterator<Item = &'a Pat<'tcx>> + Captures<'p>

Iterate over the first component of each row

pub(super) fn head_ctors<'a>(
    &'a self,
    cx: &'a MatchCheckCtxt<'p, 'tcx>
) -> impl Iterator<Item = &'a Constructor<'tcx>> + Captures<'p> + Clone

Iterate over the first constructor of each row.

pub(super) fn head_ctors_and_spans<'a>(
    &'a self,
    cx: &'a MatchCheckCtxt<'p, 'tcx>
) -> impl Iterator<Item = (&'a Constructor<'tcx>, Span)> + Captures<'p>

Iterate over the first constructor and the corresponding span of each row.

fn specialize_constructor(
    &self,
    pcx: PatCtxt<'_, 'p, 'tcx>,
    ctor: &Constructor<'tcx>,
    ctor_wild_subpatterns: &Fields<'p, 'tcx>
) -> Matrix<'p, 'tcx>

This computes S(constructor, self). See top of the file for explanations.

Trait Implementations

impl<'p, 'tcx> Clone for Matrix<'p, 'tcx>

fn clone(&self) -> Matrix<'p, 'tcx>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'p, 'tcx> Debug for Matrix<'p, 'tcx>

Pretty-printer for matrices of patterns, example:

+ _     + []                +
+ true  + [First]           +
+ true  + [Second(true)]    +
+ false + [_]               +
+ _     + [_, _, tail @ ..] +

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

Formats the value using the given formatter.

impl<'p, 'tcx> FromIterator<PatStack<'p, 'tcx>> for Matrix<'p, 'tcx>

fn from_iter<T>(iter: T) -> Self where
    T: IntoIterator<Item = PatStack<'p, 'tcx>>, 

Creates a value from an iterator.

impl<'p, 'tcx> PartialEq<Matrix<'p, 'tcx>> for Matrix<'p, 'tcx>

fn eq(&self, other: &Matrix<'p, 'tcx>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Matrix<'p, 'tcx>) -> bool

This method tests for !=.

impl<'p, 'tcx> StructuralPartialEq for Matrix<'p, 'tcx>