pub enum Value<M> {
    Null,
    Boolean(bool),
    Number(NumberBuf),
    String(String),
    Array(Array<M>),
    Object(Object<M>),
}
Expand description

Value.

The type parameter M is the type of metadata attached to each syntax node (values, sub values and object keys). The metadata is derived from the locspan::Span of the node in the source document using the metadata builder function passed to the parsing function (see the Parse trait for more details).

Parsing

You can parse a Value by importing the Parse trait providing a collection of parsing functions.

Example

use json_syntax::{Value, Parse};
use locspan::{Meta, Span};

let value: Meta<Value<Span>, Span> = Value::parse_str("{ \"key\": \"value\" }", |span| span).unwrap();

You don’t need to specify the return type, here only shown to make it clear. Furthermore the MetaValue<Span> type alias can be used instead of Meta<Value<Span>, Span> to avoid repetition of the metadata type.

Comparison

This type implements the usual comparison traits PartialEq, Eq, PartialOrd and Ord. However these implementations will also compare the metadata. If you want to do comparisons while ignoring ths metadata, you can use the locspan::Stripped type (combined with the locspan::BorrowStripped trait).

Example

use json_syntax::{Value, Parse};
use locspan::BorrowStripped;

let a = Value::parse_str("null", |_| 0).unwrap();
let b = Value::parse_str("null", |_| 1).unwrap();

assert_ne!(a, b); // not equals because the metadata is different.
assert_eq!(a.stripped(), b.stripped()); // equals because the metadata is ignored.

Printing

The Print trait provide a highly configurable printing method.

Example

use json_syntax::{Value, Parse, Print};

let value = Value::parse_str("[ 0, 1, { \"key\": \"value\" }, null ]", |span| span).unwrap();

println!("{}", value.pretty_print()); // multi line, indent with 2 spaces
println!("{}", value.inline_print()); // single line, spaces
println!("{}", value.compact_print()); // single line, no spaces

let mut options = json_syntax::print::Options::pretty();
options.indent = json_syntax::print::Indent::Tabs(1);
println!("{}", value.print_with(options)); // multi line, indent with tabs

Variants

Null

null.

Boolean(bool)

Boolean true or false.

Number(NumberBuf)

Number.

String(String)

String.

Array(Array<M>)

Array.

Object(Object<M>)

Object.

Implementations

Recursively count the number of values for which f returns true.

Returns the volume of the value.

The volume is the sum of all values and recursively nested values included in self, including self (the volume is at least 1).

This is equivalent to value.traverse().filter(StrippedFragmentRef::is_value).count().

Recursively maps the metadata inside the value.

Tries to recursively maps the metadata inside the value.

Trait Implementations

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

Converts to this type from the input type.

Converts to this type from the input type.

Converts to this type from the input type.

Converts to this type from the input type.

Converts to this type from the input type.

Converts to this type from the input type.

Converts to this type from the input type.

Converts to this type from the input type.

Converts to this type from the input type.

Converts to this type from the input type.

Converts to this type from the input type.

Converts to this type from the input type.

Converts to this type from the input type.

Converts to this type from the input type.

Converts to this type from the input type.

Converts to this type from the input type.

Feeds this value into the given Hasher. Read more

Feeds a slice of this type into the given Hasher. Read more

Maps the metadata, recursively.

This method returns an Ordering between self and other. Read more

Compares and returns the maximum of two values. Read more

Compares and returns the minimum of two values. Read more

Restrict a value to a certain interval. Read more

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason. Read more

This method returns an ordering between self and other values if one exists. Read more

This method tests less than (for self and other) and is used by the < operator. Read more

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more

This method tests greater than (for self and other) and is used by the > operator. Read more

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

Print the value with Options::pretty options.

Print the value with Options::compact options.

Print the value with Options::inline options.

Print the value with the given options.

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.

Tries to map the metadata, recursively.

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Wraps self inside a Meta<Self, M> using the given metadata. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

Uses borrowed data to replace owned data, usually by cloning. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.