Enum Selector

pub enum Selector {
    Root,
    Dot(Box<Selector>, DotArg),
    Index(Box<Selector>, IndexArg),
}

A JSON path selector (in EQL dialect, which is a subset of general JSON Path)

Variants

Root

The $ operator. Matches the root of the document

Dot(Box<Selector>, DotArg)

The . operator. Selects subfields of the nodes returned by the left argument.

Index(Box<Selector>, IndexArg)

Selects subnodes of the left argument by numeric index, by field name or by wildcard.

The array indexing operator [idx], where idx can be a number or a string.

Range indexes are not accepted.

Implementations

impl Selector

pub fn parse(input: &str) -> Result<Selector, ParseError>

Tries to parse a Selector from a &str.

Returns Ok(selector) if succesfull, Err(ParseError) on failure.

pub fn eval(&self, value: &Value) -> Value

Evaluates the Selector, returning a Value::Array.

pub fn canonicalise(&self) -> Self

Canonicalises the Selector so that for cases where there is more than one syntax for expressing the same intent, one particular way is chosen

For example, in JSONPath $.foo and $['foo'] mean the same thing. In this particular case, the second form is also more flexible because the field can contain “.” as in $['foo.bar'].

The particular syntax above is the only kind of syntax that has special consideration for canonicalisation - other syntax forms are preserved.

Trait Implementations

impl Clone for Selector

fn clone(&self) -> Selector

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Selector

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for Selector

fn fmt(&self, __derive_more_f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for Selector

fn eq(&self, other: &Selector) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for Selector

impl StructuralPartialEq for Selector