Trait Matcher 

pub trait Matcher:
    Send
    + Sync
    + 'static {
    type View<'a>;

    // Required method
    fn try_match(parent: &Expression) -> Option<Self::View<'_>>;
}

Trait that abstracts over matching on expression types.

Required Associated Types

type View<'a>

The view type returned when matching succeeds.

Required Methods

fn try_match(parent: &Expression) -> Option<Self::View<'_>>

Try to match/downcast the parent expression. Returns Some if the parent matches this matcher’s criteria, None otherwise.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl Matcher for AnyScalarFn

type View<'a> = &'a ScalarFn

impl Matcher for Any

type View<'a> = &'a Expression

impl<F: VTable> Matcher for ExactScalarFn<F>

type View<'a> = &'a <F as VTable>::Options

impl<V: VTable> Matcher for Exact<V>

type View<'a> = ExpressionView<'a, V>