Struct ZNullable 

pub struct ZNullable<T>
where
    T: VldSchema,
{ /* private fields */ }

Wraps a schema to allow null values.

If the value is null, returns Ok(None). Otherwise, delegates to the inner schema and wraps the result in Some.

The difference from ZOptional is semantic:

• optional(): field can be missing entirely
• nullable(): field must be present but can be null

At the Value level both behave the same. The distinction matters when used with the schema! macro for object validation.

Implementations

impl<T> ZNullable<T>

where T: VldSchema,

pub fn new(inner: T) -> ZNullable<T>

pub fn inner_schema(&self) -> &T

Access the inner schema (for JSON Schema generation).

Trait Implementations

impl<T> VldSchema for ZNullable<T>

where T: VldSchema,

type Output = Option<<T as VldSchema>::Output>

The Rust type produced by this schema after successful parsing.

fn parse_value( &self, value: &Value, ) -> Result<Option<<T as VldSchema>::Output>, VldError>

Parse and validate a serde_json::Value.

fn parse<I>(&self, input: &I) -> Result<Self::Output, VldError>

where I: VldInput + ?Sized,

Parse from any supported input (JSON string, file path, serde_json::Value, etc.)

fn optional(self) -> ZOptional<Self>

Make this field optional. Missing or null values become None.

fn nullable(self) -> ZNullable<Self>

Allow null values. Null becomes None.

fn with_default(self, value: Self::Output) -> ZDefault<Self>

where Self::Output: Clone,

Provide a default value when the field is missing or null.

fn refine<F>(self, check: F, message: &str) -> ZRefine<Self, F>

where F: Fn(&Self::Output) -> bool,

Add a custom refinement check without changing the output type.

fn transform<F, U>(self, f: F) -> ZTransform<Self, F, U>

where F: Fn(Self::Output) -> U,

Transform the output value after successful parsing.

fn nullish(self) -> ZNullish<Self>

Make this field nullish (both optional and nullable).

fn catch(self, fallback: Self::Output) -> ZCatch<Self>

where Self::Output: Clone,

Return a fallback value on ANY validation error.

fn pipe<S>(self, next: S) -> ZPipe<Self, S>

where S: VldSchema, Self::Output: Serialize,

Chain this schema’s output into another schema.

fn describe(self, description: &str) -> ZDescribe<Self>

Attach a human-readable description/label to this schema.

fn super_refine<F>(self, check: F) -> ZSuperRefine<Self, F>

where F: Fn(&Self::Output, &mut VldError),

Add a custom refinement that can produce multiple errors.

fn or<B>(self, other: B) -> ZUnion2<Self, B>

where B: VldSchema,

Create a union: this schema or another. Returns Either<Self::Output, B::Output>.

fn and<B>(self, other: B) -> ZIntersection<Self, B>

where B: VldSchema,

Create an intersection: input must satisfy both schemas.

fn message(self, msg: impl Into<String>) -> ZMessage<Self>

Override the error message for this schema.