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JsonBackend

docspec_json::backend

Trait JsonBackend 

Source 
pub trait JsonBackend {
    type Output;

    // Required methods
    fn begin_array(&mut self) -> Result<()>;
    fn begin_object(&mut self) -> Result<()>;
    fn end_array(&mut self) -> Result<()>;
    fn end_object(&mut self) -> Result<()>;
    fn finish(self) -> Result<Self::Output>;
    fn write_bool(&mut self, b: bool) -> Result<()>;
    fn write_name(&mut self, name: &str) -> Result<()>;
    fn write_null(&mut self) -> Result<()>;
    fn write_number(&mut self, n: u32) -> Result<()>;
    fn write_string(&mut self, s: &str) -> Result<()>;

    // Provided method
    fn write_string_streaming<F>(&mut self, f: F) -> Result<()>
       where F: FnOnce(&mut dyn Write) -> Result<()> { ... }
}
Expand description

Low-level JSON token emitter. Implementations write JSON tokens to an underlying sink. State validation is performed by crate::JsonEmitter, not by the backend.

Required Associated Types§

Source

type Output

Type returned by JsonBackend::finish.

Required Methods§

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fn begin_array(&mut self) -> Result<()>

Begin a JSON array (writes [).

§Errors

Returns any error produced by the underlying backend.

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fn begin_object(&mut self) -> Result<()>

Begin a JSON object (writes {).

§Errors

Returns any error produced by the underlying backend.

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fn end_array(&mut self) -> Result<()>

End the current JSON array (writes ]).

§Errors

Returns any error produced by the underlying backend.

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fn end_object(&mut self) -> Result<()>

End the current JSON object (writes }).

§Errors

Returns any error produced by the underlying backend.

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fn finish(self) -> Result<Self::Output>

Finish writing and return the backend’s output.

§Errors

Returns any error produced by the underlying backend.

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fn write_bool(&mut self, b: bool) -> Result<()>

Write a boolean value.

§Errors

Returns any error produced by the underlying backend.

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fn write_name(&mut self, name: &str) -> Result<()>

Write an object key.

§Errors

Returns any error produced by the underlying backend.

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fn write_null(&mut self) -> Result<()>

Write a null value.

§Errors

Returns any error produced by the underlying backend.

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fn write_number(&mut self, n: u32) -> Result<()>

Write a u32 numeric value.

§Errors

Returns any error produced by the underlying backend.

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fn write_string(&mut self, s: &str) -> Result<()>

Write a string value.

§Errors

Returns any error produced by the underlying backend.

Provided Methods§

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fn write_string_streaming<F>(&mut self, f: F) -> Result<()>
where F: FnOnce(&mut dyn Write) -> Result<()>,

Write a string value by streaming bytes through a closure.

The default implementation buffers the bytes into a Vec<u8>, converts to a &str, and delegates to write_string.

§Errors

Returns an error if the closure returns an I/O error, or if the buffered bytes are not valid UTF-8.

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§