Struct FieldContract 

pub struct FieldContract {
    pub name: String,
    pub field_type: ContractFieldType,
    pub required: bool,
    pub nullable: bool,
    pub allowed_values: Option<Vec<Value>>,
    pub pattern: Option<String>,
    pub min: Option<f64>,
    pub max: Option<f64>,
    pub min_length: Option<usize>,
    pub max_length: Option<usize>,
    pub description: Option<String>,
}

Available on crate feature contract only.

One promised top-level field: its type plus optional semantic constraints.

Fields

name: String

Top-level field name (contracts describe the output’s top-level shape; nested objects are typed as object).

field_type: ContractFieldType

Declared type. integer means a JSON number with no fractional part; number accepts any JSON number.

required: bool

When true (default) the field must be present in every record. A non-required field that is absent skips all other checks.

nullable: bool

When true, an explicit JSON null is allowed (and skips the type/constraint checks). Default false.

allowed_values: Option<Vec<Value>>

Allowed values (exact JSON equality). Must be non-empty when present, and every value must match the declared type. Use nullable for null — null is not allowed inside enum.

pattern: Option<String>

Regex the value must match. string fields only.

min: Option<f64>

Minimum numeric value (inclusive). integer/number fields only.

max: Option<f64>

Maximum numeric value (inclusive). integer/number fields only.

min_length: Option<usize>

Minimum string length in characters (inclusive). string fields only.

max_length: Option<usize>

Maximum string length in characters (inclusive). string fields only.

description: Option<String>

Column description (documentation metadata; carried into exports).

Trait Implementations

impl Clone for FieldContract

fn clone(&self) -> FieldContract

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FieldContract

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for FieldContract

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl JsonSchema for FieldContract

fn schema_name() -> Cow<'static, str>

The name of the generated JSON Schema.

fn schema_id() -> Cow<'static, str>

Returns a string that uniquely identifies the schema produced by this type.

fn json_schema(generator: &mut SchemaGenerator) -> Schema

Generates a JSON Schema for this type.

fn inline_schema() -> bool

Whether JSON Schemas generated for this type should be included directly in parent schemas, rather than being re-used where possible using the $ref keyword.

impl Serialize for FieldContract

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.