Struct TreeDecoder 

pub struct TreeDecoder<'de> { /* private fields */ }

A FormatDecoder that replays an owned token stream produced from a Value tree.

Formats that parse their input into a Value first wrap that stream in this type instead of re-implementing the full FormatDecoder contract. The inner decoder borrows the owned stream for the lifetime of the wrapper; object_key / string are re-lifetimed to the caller’s 'de.

Implementations

impl<'de> TreeDecoder<'de>

pub fn new(tokens: Vec<Token<'static>>) -> Self

Wrap an owned token stream produced by value_to_tokens.

pub fn end(&mut self) -> Result<()>

Validate that the whole token stream was consumed.

Trait Implementations

impl<'de> FormatDecoder<'de> for TreeDecoder<'de>

type Error = Error

The error type produced by this format’s methods.

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

Consume { (with depth check).

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

Consume }.

fn object_key(&mut self) -> Result<Option<Cow<'de, str>>, Self::Error>

Read the next object key; returns None on } (not consumed).

fn object_entry_sep(&mut self) -> Result<bool, Self::Error>

Object entry separator: true if more entries follow, false at end.

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

Consume [ (with depth check).

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

Consume ].

fn array_has_more(&mut self) -> Result<bool, Self::Error>

Whether the array has more elements (] not consumed).

fn array_entry_sep(&mut self) -> Result<bool, Self::Error>

Array entry separator: true if more elements follow, false at end.

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

Consume null.

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

Read a boolean.

fn number(&mut self) -> Result<Number, Self::Error>

Read a number.

fn string(&mut self) -> Result<Cow<'de, str>, Self::Error>

Read a string (may borrow the source).

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

Read a single character (a one-scalar string).

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

Skip any one value.

fn peek_token(&mut self) -> Result<Token<'de>, Self::Error>

Peek the next token without consuming it (container-flatten support).

fn next_token(&mut self) -> Result<Token<'de>, Self::Error>

Consume and return the next token.

fn save(&self) -> Mark

Save the current position (for untagged-enum backtracking).

fn restore(&mut self, mark: Mark)

Restore a position saved with save.

fn set_expecting(&mut self, _expecting: &'static str) -> Option<&'static str>

Set the human-readable description of the type currently being decoded, so container-level type-mismatch errors (begin_object / begin_array hitting the wrong token) can name the expected type instead of a bare structural token like '{'.

fn i8(&mut self) -> Result<i8, Self::Error>

Read a $t (default: read a number and convert).

fn i16(&mut self) -> Result<i16, Self::Error>

Read a $t (default: read a number and convert).

fn i32(&mut self) -> Result<i32, Self::Error>

Read a $t (default: read a number and convert).

fn i64(&mut self) -> Result<i64, Self::Error>

Read a $t (default: read a number and convert).

fn i128(&mut self) -> Result<i128, Self::Error>

Read a $t (default: read a number and convert).

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

Read a $t (default: read a number and convert).

fn u8(&mut self) -> Result<u8, Self::Error>

Read a $t (default: read a number and convert).

fn u16(&mut self) -> Result<u16, Self::Error>

Read a $t (default: read a number and convert).

fn u32(&mut self) -> Result<u32, Self::Error>

Read a $t (default: read a number and convert).

fn u64(&mut self) -> Result<u64, Self::Error>

Read a $t (default: read a number and convert).

fn u128(&mut self) -> Result<u128, Self::Error>

Read a $t (default: read a number and convert).

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

Read a $t (default: read a number and convert).

fn bytes(&mut self) -> Result<Cow<'de, [u8]>, Self::Error>

Read a byte sequence (may borrow the source).

fn option_tag(&mut self) -> Result<OptionTag, Self::Error>

Report whether the next value is Option::None or Option::Some.

fn map_key<K: for<'a> NsonDeserialize<'a>>( &mut self, ) -> Result<Option<K>, Self::Error>

Read the next map key.

fn is_human_readable(&self) -> bool

Whether this format produces human-readable output.