Crate facet_value 

facet-value provides a memory-efficient dynamic value type for representing structured data similar to JSON, but with added support for binary data and datetime.

Features

• Pointer-sized Value type: The main Value type is exactly one pointer in size
• Eight value types: Null, Bool, Number, String, Bytes, Array, Object, DateTime
• no_std compatible: Works with just alloc, no standard library required
• Bytes support: First-class support for binary data (useful for MessagePack, CBOR, etc.)
• DateTime support: First-class support for temporal data (useful for TOML, YAML, etc.)

Design

Value uses a tagged pointer representation with 8-byte alignment, giving us 3 tag bits to distinguish between value types. Inline values (null, true, false) don’t require heap allocation.

Macros

value

Creates a Value from a JSON-like syntax.

Structs

ArrayIntoIter

Iterator over owned Values from a VArray.

FormattedValue

Result of formatting a value with span tracking

Iter

Iterator over (&VString, &Value) pairs.

IterMut

Iterator over (&VString, &mut Value) pairs.

Keys

Iterator over keys.

ObjectIntoIter

Iterator over owned (VString, Value) pairs.

VArray

An array value.

VBytes

A binary data value.

VDateTime

A datetime value.

VNumber

A JSON number value.

VObject

An object (map) value.

VQName

A qualified name consisting of an optional namespace and a local name.

VSafeString

A string value marked as “safe” (e.g., pre-escaped HTML that should not be escaped again).

VString

A string value.

VUuid

A 128-bit universally unique identifier (UUID).

Value

A dynamic value that can represent null, booleans, numbers, strings, bytes, arrays, or objects.

ValueError

Error type for Value deserialization.

Values

Iterator over values.

ValuesMut

Iterator over mutable values.

Enums

DateTimeKind

The kind of datetime value.

Destructured

Enum for destructuring a Value by ownership.

DestructuredMut

Enum for destructuring a Value by mutable reference.

DestructuredRef

Enum for destructuring a Value by reference.

OtherKind

Secondary discriminant for “Other” types (tag 7).

PathSegment

A segment in a deserialization path

ValueErrorKind

Specific error kinds for Value deserialization.

ValueType

Enum distinguishing the value types.

Statics

VALUE_SHAPE

The static shape for Value.

Functions

format_value

Format a Value as JSON-like text (no span tracking, just plain output)

format_value_with_spans

Format a Value as JSON-like text with span tracking

from_value

Deserialize a Value into any type implementing Facet.