Struct Matcher 

pub struct Matcher<I, A> { /* private fields */ }

Ordered pattern matcher: first matching arm wins.

Implementations

impl<I: 'static, A: 'static> Matcher<I, A>

pub fn new() -> Self

Empty matcher with no arms and no default.

pub fn when( self, pred: Predicate<I>, handler: impl Fn(I) -> A + Send + Sync + 'static, ) -> Self

Add a predicate arm evaluated before later arms.

pub fn tag( self, expected: impl Into<String>, handler: impl Fn(I) -> A + Send + Sync + 'static, ) -> Self

where I: HasTag,

Add a tag arm: matches when HasTag::tag equals expected (string equality).

pub fn or_else(self, handler: impl Fn(I) -> A + Send + Sync + 'static) -> Self

Fallback when no arm matches (used by Matcher::exhaustive only).

pub fn run_exhaustive(self, input: I) -> A

Run this matcher once. Unlike Self::exhaustive, does not require I: Send (no shareable closure).

pub fn exhaustive(self) -> impl Fn(I) -> A

where I: 'static, A: 'static,

Fn(I) -> A that panics when nothing matches and no Matcher::or_else was set.

The closure is only Send + Sync when I: Send (it captures Arc<Matcher<…>> and may be invoked with I across threads).

pub fn option(self) -> impl Fn(I) -> Option<A> + Send + Sync

where I: 'static, A: 'static,

Fn(I) -> Option<A> — None when unmatched; or_else is ignored.

pub fn either(self) -> impl Fn(I) -> Result<A, I> + Send + Sync

where I: 'static, A: 'static,

Fn(I) -> Result<A, I> — Err carries the original input when unmatched; or_else is ignored.

Trait Implementations

impl<I: 'static, A: 'static> Default for Matcher<I, A>

fn default() -> Self

Returns the “default value” for a type.