Trait Processor

pub trait Processor: 'static + Sized {
    // Required method
    fn process(&self, tree: Tree) -> Result;

    // Provided methods
    fn or<P: Processor>(self, processor: P) -> WithFallback<Self, P> { ... }
    fn or_stdout(self) -> WithFallback<Self, Printer<Pretty, MakeStdout>> { ... }
    fn or_stderr(self) -> WithFallback<Self, Printer<Pretty, MakeStderr>> { ... }
    fn or_none(self) -> WithFallback<Self, Sink> { ... }
}

A trait for processing completed Trees.

Processors are responsible for both formatting and writing logs to their intended destinations. This is typically implemented using Formatter, MakeWriter, and io::Write.

While this trait may be implemented on downstream types, from_fn provides a convenient interface for creating Processors without having to explicitly define new types.

Required Methods

fn process(&self, tree: Tree) -> Result

Process a Tree. This can mean many things, such as writing to stdout or a file, sending over a network, storing in memory, ignoring, or anything else.

Errors

If the Tree cannot be processed, then it is returned along with a Box<dyn Error + Send + Sync>. If the processor is configured with a fallback processor from Processor::or, then the Tree is deferred to that processor.

Provided Methods

fn or<P: Processor>(self, processor: P) -> WithFallback<Self, P>

Returns a Processor that first attempts processing with self, and resorts to processing with fallback on failure.

Note that or_stdout, or_stderr, and or_none can be used as shortcuts for pretty printing or dropping the Tree entirely.

fn or_stdout(self) -> WithFallback<Self, Printer<Pretty, MakeStdout>>

Returns a Processor that first attempts processing with self, and resorts to pretty-printing to stdout on failure.

fn or_stderr(self) -> WithFallback<Self, Printer<Pretty, MakeStderr>>

Returns a Processor that first attempts processing with self, and resorts to pretty-printing to stderr on failure.

fn or_none(self) -> WithFallback<Self, Sink>

Returns a Processor that first attempts processing with self, otherwise silently fails.

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.

Implementations on Foreign Types

impl<P: Processor> Processor for Box<P>

fn process(&self, tree: Tree) -> Result

impl<P: Processor> Processor for Arc<P>

fn process(&self, tree: Tree) -> Result

Implementors

impl Processor for Sink

impl<F> Processor for TestCapturePrinter<F>

where F: 'static + Formatter,

impl<F> Processor for FromFn<F>

where F: 'static + Fn(Tree) -> Result,

impl<F, W> Processor for Printer<F, W>

where F: 'static + Formatter, W: 'static + for<'a> MakeWriter<'a>,

impl<P, F> Processor for WithFallback<P, F>

where P: Processor, F: Processor,

impl<P: Processor> Processor for InnerSender<P>

Available on crate feature tokio only.