Struct ion_rs::SystemReader

pub struct SystemReader<R: RawReader> { /* private fields */ }

A streaming Ion reader that:

• maintains a symbol table
• processes local symbol tables as they are encountered
• can resolve symbol IDs into their associated text
• does NOT filter out encoding data like IVMs and symbol tables

SystemReader itself is format-agnostic; all format-specific logic is handled by the wrapped RawReader implementation.

If the user skips over some or all of a local symbol table in the stream (via either next() or step_out()), the SystemReader will automatically process the rest of the local symbol table before advancing. This allows users to visit Ion values used to encode local symbol tables without also being responsible for interpreting them (as they would with an implementation of the RawReader trait.)

Implementations

impl<R: RawReader> SystemReader<R>

pub fn new(raw_reader: R) -> SystemReader<R>

pub fn raw_annotations(&self) -> impl Iterator<Item = RawSymbolToken> + '_

pub fn symbol_table(&self) -> &SymbolTable

pub fn read_raw_symbol(&mut self) -> IonResult<RawSymbolToken>

pub fn raw_field_name_token(&mut self) -> IonResult<RawSymbolToken>

pub fn current_string_was_consumed(&self) -> bool

impl<T: AsRef<[u8]> + Expandable> SystemReader<RawBinaryReader<T>>

Functionality that is only available if the data source we’re reading from is in-memory, like a Vec<u8> or &[u8].

pub fn raw_bytes(&self) -> Option<&[u8]>

pub fn raw_field_id_bytes(&self) -> Option<&[u8]>

pub fn raw_header_bytes(&self) -> Option<&[u8]>

pub fn raw_value_bytes(&self) -> Option<&[u8]>

pub fn raw_annotations_bytes(&self) -> Option<&[u8]>

pub fn field_id_length(&self) -> Option<usize>

pub fn field_id_offset(&self) -> Option<usize>

pub fn field_id_range(&self) -> Option<Range<usize>>

pub fn annotations_length(&self) -> Option<usize>

pub fn annotations_offset(&self) -> Option<usize>

pub fn annotations_range(&self) -> Option<Range<usize>>

pub fn header_length(&self) -> usize

pub fn header_offset(&self) -> usize

pub fn header_range(&self) -> Range<usize>

pub fn value_length(&self) -> usize

pub fn value_offset(&self) -> usize

pub fn value_range(&self) -> Range<usize>

Trait Implementations

impl<R: RawReader> IonReader for SystemReader<R>

fn next(&mut self) -> IonResult<Self::Item>

Advances the system reader to the next raw stream element.

type Item = SystemStreamItem

The type returned by calls to Self::next, indicating the next entity in the stream. Reader implementations representing different levels of abstraction will surface different sets of encoding artifacts. While an application-level Reader would only surface Ion values, a lower level Reader might surface symbol tables, Ion version markers, etc.

type Symbol = Symbol

The types used to represent field names, annotations, and symbol values at this Reader’s level of abstraction.

fn current(&self) -> Self::Item

Returns a value describing the stream entity over which the Reader is currently positioned. Depending on the Reader’s level of abstraction, that entity may or may not be an Ion value.

fn step_in(&mut self) -> IonResult<()>

If the current value is a container (i.e. a struct, list, or s-expression), positions the cursor at the beginning of that container’s sequence of child values. The application must call Self::next() to advance to the first child value. If the current value is not a container, returns crate::IonError.

fn step_out(&mut self) -> IonResult<()>

Positions the cursor at the end of the container currently being traversed. Calling Self::next() will position the cursor over the item that follows the container. If the cursor is not in a container (i.e. it is already at the top level), returns crate::IonError.

fn field_name(&self) -> IonResult<Symbol>

If the current item is a field within a struct, returns Ok(_) with a Self::Symbol representing the field’s name; otherwise, returns an crate::IonError::IllegalOperation.

fn annotations<'a>(&'a self) -> Box<dyn Iterator<Item = IonResult<Symbol>> + 'a>

Returns an iterator that will yield each of the annotations for the current value in order. If there is no current value, returns an empty iterator.

fn read_symbol(&mut self) -> IonResult<Self::Symbol>

Attempts to read the current item as an Ion symbol and return it as a Self::Symbol. If the current item is not a symbol or an IO error is encountered while reading, returns crate::IonError.

fn read_string(&mut self) -> IonResult<Str>

Attempts to read the current item as an Ion string and return it as a String. If the current item is not a string or an IO error is encountered while reading, returns crate::IonError.

fn read_str(&mut self) -> IonResult<&str>

Attempts to read the current item as an Ion string and return it as a &str. If the current item is not a string or an IO error is encountered while reading, returns crate::IonError.

fn is_null(&self) -> bool

Returns true if the reader is currently positioned over an Ion null of any type.

fn ion_version(&self) -> (u8, u8)

Returns the (major, minor) version of the Ion stream being read. If ion_version is called before an Ion Version Marker has been read, the version (1, 0) will be returned.

fn ion_type(&self) -> Option<IonType>

If the current item is a value, returns that value’s Ion type. Otherwise, returns None.

fn read_null(&mut self) -> IonResult<IonType>

Attempts to read the current item as an Ion null and return its Ion type. If the current item is not a null or an IO error is encountered while reading, returns crate::IonError.

fn read_bool(&mut self) -> IonResult<bool>

Attempts to read the current item as an Ion boolean and return it as a bool. If the current item is not a boolean or an IO error is encountered while reading, returns crate::IonError.

fn read_int(&mut self) -> IonResult<Int>

Attempts to read the current item as an Ion integer and return it as an Int. If the current item is not an integer or an IO error is encountered while reading, returns crate::IonError.

fn read_i64(&mut self) -> IonResult<i64>

Attempts to read the current item as an Ion integer and return it as an i64. If the current item is not an integer, the integer is too large to be represented as an i64, or an IO error is encountered while reading, returns crate::IonError.

fn read_f32(&mut self) -> IonResult<f32>

Attempts to read the current item as an Ion float and return it as an f32. If the current item is not a float or an IO error is encountered while reading, returns crate::IonError.

fn read_f64(&mut self) -> IonResult<f64>

Attempts to read the current item as an Ion float and return it as an f64. If the current item is not a float or an IO error is encountered while reading, returns crate::IonError.

fn read_decimal(&mut self) -> IonResult<Decimal>

Attempts to read the current item as an Ion decimal and return it as a crate::Decimal. If the current item is not a decimal or an IO error is encountered while reading, returns crate::IonError.

fn read_blob(&mut self) -> IonResult<Blob>

Attempts to read the current item as an Ion blob and return it as a Vec<u8>. If the current item is not a blob or an IO error is encountered while reading, returns crate::IonError.

fn read_clob(&mut self) -> IonResult<Clob>

Attempts to read the current item as an Ion clob and return it as a Vec<u8>. If the current item is not a clob or an IO error is encountered while reading, returns crate::IonError.

fn read_timestamp(&mut self) -> IonResult<Timestamp>

Attempts to read the current item as an Ion timestamp and return crate::Timestamp. If the current item is not a timestamp or an IO error is encountered while reading, returns crate::IonError.

fn depth(&self) -> usize

Returns a usize indicating the Reader’s current level of nesting. That is: the number of times the Reader has stepped into a container without later stepping out. At the top level, this method returns 0.

fn parent_type(&self) -> Option<IonType>

If the reader is positioned at the top level, returns None. Otherwise, returns Some(_) with the parent container’s crate::IonType.

fn has_annotations(&self) -> bool

If the reader is positioned over a value with one or more annotations, returns true. Otherwise, returns false.

fn number_of_annotations(&self) -> usize

Returns the number of annotations on the current value. If there is no current value, returns zero.