Struct CedarValueMapper 

pub struct CedarValueMapper { /* private fields */ }

Mapper for bidirectional JSON ↔ Cedar value conversion.

Provides methods to convert between serde_json::Value and Cedar’s RestrictedExpression, with support for all Cedar data types including extension types (IP addresses, decimals).

Implementations

impl CedarValueMapper

pub fn new() -> Self

Create a new mapper with default settings.

pub fn new_without_auto_detect() -> Self

Create a mapper with auto-detection of extension types disabled.

pub fn with_max_size(self, max_size: usize) -> Self

Set the maximum allowed value size in bytes.

A value of 0 means no limit.

pub fn json_to_cedar( &self, value: &Value, ) -> Result<Option<RestrictedExpression>, ValueMappingError>

Convert a JSON value to a Cedar RestrictedExpression.

Supports all Cedar primitive types, collections, and extension types. Null values are not supported and will return an error.

pub fn json_to_cedar_with_type( &self, value: &Value, ) -> Result<Option<(RestrictedExpression, CedarType)>, ValueMappingError>

Convert a JSON value to Cedar, returning the inferred Cedar type.

This is useful when you need both the expression and type information.

pub fn cedar_to_json(expr_json: &Value) -> Result<Value, ValueMappingError>

Convert a Cedar expression back to JSON format.

This is useful for serializing Cedar values for storage or transmission. Entity references are converted to {"type": "...", "id": "..."} format. Extension types are converted to {"__extn": {"fn": "...", "arg": "..."}} format.

Note

This method works with the JSON representation of Cedar values, not the evaluated result. For evaluated results, use eval_result_to_json.

pub fn get_nested<'a>( value: &'a Value, path: &str, ) -> Result<&'a Value, ValueMappingError>

Access a nested value using dot notation.

pub fn set_nested( value: &mut Value, path: &str, new_value: Value, ) -> Result<(), ValueMappingError>

Set a value at a nested path, creating intermediate objects as needed.

pub fn detect_extension(value: &str) -> Option<ExtensionValue>

Detect if a string value represents a Cedar extension type.

Detects the following extension types:

• ipaddr: IP addresses (IPv4/IPv6) and CIDR ranges (e.g., “192.168.1.1”, “10.0.0.0/8”)
• decimal: Fixed-precision decimals (e.g., “3.14”, “-12.345”)
• datetime: ISO 8601 / RFC 3339 timestamps (e.g., “2024-10-15T11:35:00Z”)
• duration: Duration strings (e.g., “2h30m”, “1d12h”, “500ms”)

See: https://docs.cedarpolicy.com/policies/syntax-datatypes.html#datatype-extension

pub fn is_entity_reference(value: &Value) -> bool

Check if a value represents a Cedar entity reference.

pub fn value_type_name(value: &Value) -> &'static str

Get the JSON type name of a value.

Trait Implementations

impl Clone for CedarValueMapper

fn clone(&self) -> CedarValueMapper

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CedarValueMapper

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

Formats the value using the given formatter.

impl Default for CedarValueMapper

fn default() -> Self

Returns the “default value” for a type.