rustc_pattern_analysis

Trait PatCx

source 
pub trait PatCx: Sized + Debug {
    type Ty: Clone + Debug;
    type Error: Debug;
    type VariantIdx: Clone + Idx + Debug;
    type StrLit: Clone + PartialEq + Debug;
    type ArmData: Copy + Clone + Debug;
    type PatData: Clone;

    // Required methods
    fn is_exhaustive_patterns_feature_on(&self) -> bool;
    fn ctor_arity(&self, ctor: &Constructor<Self>, ty: &Self::Ty) -> usize;
    fn ctor_sub_tys<'a>(
        &'a self,
        ctor: &'a Constructor<Self>,
        ty: &'a Self::Ty,
    ) -> impl Iterator<Item = (Self::Ty, PrivateUninhabitedField)> + ExactSizeIterator + Captures<'a>;
    fn ctors_for_ty(
        &self,
        ty: &Self::Ty,
    ) -> Result<ConstructorSet<Self>, Self::Error>;
    fn write_variant_name(
        f: &mut Formatter<'_>,
        ctor: &Constructor<Self>,
        ty: &Self::Ty,
    ) -> Result;
    fn bug(&self, fmt: Arguments<'_>) -> Self::Error;
    fn complexity_exceeded(&self) -> Result<(), Self::Error>;

    // Provided methods
    fn lint_overlapping_range_endpoints(
        &self,
        _pat: &DeconstructedPat<Self>,
        _overlaps_on: IntRange,
        _overlaps_with: &[&DeconstructedPat<Self>],
    ) { ... }
    fn lint_non_contiguous_range_endpoints(
        &self,
        _pat: &DeconstructedPat<Self>,
        _gap: IntRange,
        _gapped_with: &[&DeconstructedPat<Self>],
    ) { ... }
}
Expand description

Context that provides type information about constructors.

Most of the crate is parameterized on a type that implements this trait.

Required Associated Types§

source

type Ty: Clone + Debug

The type of a pattern.

source

type Error: Debug

Errors that can abort analysis.

source

type VariantIdx: Clone + Idx + Debug

The index of an enum variant.

source

type StrLit: Clone + PartialEq + Debug

A string literal

source

type ArmData: Copy + Clone + Debug

Extra data to store in a match arm.

source

type PatData: Clone

Extra data to store in a pattern.

Required Methods§

source

fn is_exhaustive_patterns_feature_on(&self) -> bool

source

fn ctor_arity(&self, ctor: &Constructor<Self>, ty: &Self::Ty) -> usize

The number of fields for this constructor.

source

fn ctor_sub_tys<'a>( &'a self, ctor: &'a Constructor<Self>, ty: &'a Self::Ty, ) -> impl Iterator<Item = (Self::Ty, PrivateUninhabitedField)> + ExactSizeIterator + Captures<'a>

The types of the fields for this constructor. The result must contain ctor_arity() fields.

source

fn ctors_for_ty( &self, ty: &Self::Ty, ) -> Result<ConstructorSet<Self>, Self::Error>

The set of all the constructors for ty.

This must follow the invariants of ConstructorSet

source

fn write_variant_name( f: &mut Formatter<'_>, ctor: &Constructor<Self>, ty: &Self::Ty, ) -> Result

Write the name of the variant represented by pat. Used for the best-effort Debug impl of DeconstructedPat. Only invoqued when pat.ctor() is Struct | Variant(_) | UnionField.

source

fn bug(&self, fmt: Arguments<'_>) -> Self::Error

Raise a bug.

source

fn complexity_exceeded(&self) -> Result<(), Self::Error>

The maximum pattern complexity limit was reached.

Provided Methods§

source

fn lint_overlapping_range_endpoints( &self, _pat: &DeconstructedPat<Self>, _overlaps_on: IntRange, _overlaps_with: &[&DeconstructedPat<Self>], )

Lint that the range pat overlapped with all the ranges in overlaps_with, where the range they overlapped over is overlaps_on. We only detect singleton overlaps. The default implementation does nothing.

source

fn lint_non_contiguous_range_endpoints( &self, _pat: &DeconstructedPat<Self>, _gap: IntRange, _gapped_with: &[&DeconstructedPat<Self>], )

Lint that there is a gap gap between pat and all of gapped_with such that the gap is not matched by another range. If gapped_with is empty, then gap is T::MAX. We only detect singleton gaps. The default implementation does nothing.

Object Safety§

This trait is not object safe.

Implementors§