Struct FieldValidator 

pub struct FieldValidator { /* private fields */ }

An application-supplied field validator with an explicit semantic revision.

The closure runs in the shared decode stage, so interactive, file, and stdin answers are validated identically. Because closure semantics cannot be fingerprinted, the application declares an explicit revision string that does enter the fingerprint: bump the revision whenever the validator’s accepted values change, and previously rendered sheets are invalidated exactly like any other semantic change.

Error messages returned by the closure are shown to users in diagnostics; they should describe the rule without echoing the submitted value.

Implementations

impl FieldValidator

pub fn new( revision: impl Into<String>, check: impl Fn(&AnswerValue) -> Result<(), String> + Send + Sync + 'static, ) -> Self

Create a validator with a semantic revision and a check that returns a user-facing message on rejection.

pub fn revision(&self) -> &str

The semantic revision that participates in the fingerprint.

Trait Implementations

impl Clone for FieldValidator

fn clone(&self) -> FieldValidator

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FieldValidator

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

Formats the value using the given formatter.

impl Eq for FieldValidator

impl PartialEq for FieldValidator

Equality compares the semantic revision only; the closure itself is not comparable, and the revision is the declared semantic identity.

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.