Enum QuantorError

pub enum QuantorError {
    PredicateFailed {
        kind: QuantorKind,
        index: usize,
    },
    EmptyInput {
        kind: QuantorKind,
    },
    NoMatch {
        kind: QuantorKind,
    },
    UnexpectedMatch {
        kind: QuantorKind,
        index: usize,
    },
    NotAllEqual {
        kind: QuantorKind,
        index: usize,
    },
    PairwiseFailed {
        kind: QuantorKind,
        index: usize,
    },
    ForAllExistsFailed {
        kind: QuantorKind,
        outer_index: usize,
    },
    ExistsForAllFailed {
        kind: QuantorKind,
        outer_index: usize,
    },
    ExactlyNFailed {
        kind: QuantorKind,
        found: usize,
        expected: usize,
    },
    Custom(&'static str),
}

Error type returned by fallible quantifier evaluations in quantor.

Variants

PredicateFailed

Returned when a predicate fails during a forall check.

Fields

kind: QuantorKind

The kind of quantifier that threw this error.

index: usize

The index of the first failing element.

EmptyInput

Returned when no elements are given.

Fields

kind: QuantorKind

The kind of quantifier that threw this error.

NoMatch

Returned when no element satisfies the predicate in an exists check.

Fields

kind: QuantorKind

The kind of quantifier that threw this error.

UnexpectedMatch

Returned when none or exactly_one fails.

Fields

kind: QuantorKind

The kind of quantifier that threw this error.

index: usize

The index of the violating element.

NotAllEqual

Returned when not all elements are equal in all_equal.

Fields

kind: QuantorKind

The kind of quantifier that threw this error.

index: usize

The index of the first element that is not equal to the other, previously checked elements.

PairwiseFailed

Returned when a pair of adjacent elements fail a pairwise predicate.

Fields

kind: QuantorKind

The kind of quantifier that threw this error.

index: usize

The index of the first element in the failing pair.

ForAllExistsFailed

Returned when a forallexists condition fails.

Fields

kind: QuantorKind

The kind of quantifier that threw this error.

outer_index: usize

The index of the outer (left) element that failed.

ExistsForAllFailed

Returned when no left-side element satisfies the existsforall condition.

Fields

kind: QuantorKind

The kind of quantifier that threw this error.

outer_index: usize

The index of the outer (left) element that failed.

ExactlyNFailed

Returned when the number of matches does not equal the expected count.

Fields

kind: QuantorKind

The kind of quantifier that threw this error.

found: usize

Number of matches found.

expected: usize

Number of matches expected.

Custom(&'static str)

A catch-all error with a static message.

Implementations

impl QuantorError

pub fn is_predicate_failed(&self) -> bool

Returns true if the quantifier failed due to a predicate mismatch.

Useful for identifying simple predicate failures, such as those from forall or exactly_one.

Returns

• true if the error variant is QuantorError::PredicateFailed.
• false otherwise.

Example

use quantor::{forall, error::QuantorResultExt};

let nums = vec![1, 2, 3];
let result = forall(&nums, |x| *x < 3);

assert!(result.is_err());
assert!(result.unwrap_err().is_predicate_failed());

pub fn is_no_match(&self) -> bool

Returns true if the quantifier failed because no element matched the predicate.

Typically used with exists or existsforall where at least one match is expected.

Returns

• true if the error variant is QuantorError::NoMatch.
• false otherwise.

Example

use quantor::{exists, error::QuantorResultExt};

let nums = [1, 2, 3];
let result = exists(&nums, |x| *x > 10);

assert!(result.is_err());
assert!(result.unwrap_err().is_no_match());

pub fn kind(&self) -> QuantorKind

Returns the QuantorKind associated with this error.

Allows inspection of which quantifier failed, regardless of the specific error variant.

Returns

• A QuantorKind value corresponding to the quantifier that produced the error.
• QuantorKind::Custom for generic errors.

Example

use quantor::{forall, error::{QuantorKind, QuantorResultExt}};

let nums = [1, 2, 3];
let result = forall(&nums, |x| *x > 3);

assert_eq!(result.unwrap_err().kind(), QuantorKind::Forall);

Trait Implementations

impl Debug for QuantorError

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

Formats the value using the given formatter.

impl Display for QuantorError

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

Formats the value using the given formatter.

impl Error for QuantorError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0: use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0: replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<&'static str> for QuantorError

fn from(msg: &'static str) -> Self

Converts to this type from the input type.

impl From<String> for QuantorError

fn from(msg: String) -> Self

Converts to this type from the input type.

impl PartialEq for QuantorError

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for QuantorError

impl StructuralPartialEq for QuantorError