Enum DerivationError 

pub enum DerivationError {
    UnknownParameter(ParameterName),
    TypeMismatch {
        op: String,
        expected: String,
        actual: String,
    },
    DivisionByZero,
    InvalidArity {
        builtin: String,
        expected: usize,
        actual: usize,
    },
    SelectionNotSupported,
}

Errors produced at Expression::eval time.

Variants

UnknownParameter(ParameterName)

A Ref(name) pointed at a parameter that isn’t in the bindings.

TypeMismatch

An operation received operands of the wrong kind.

Fields

op: String

Operator or builtin name.

expected: String

The kind the operator expected.

actual: String

The kind that was actually supplied.

DivisionByZero

Integer division or modulo by zero.

InvalidArity

A builtin received the wrong number of arguments.

Fields

builtin: String

Builtin name.

expected: usize

Expected arity.

actual: usize

Actual arity.

SelectionNotSupported

Selection values can’t flow through arithmetic/logic expressions.

Trait Implementations

impl Debug for DerivationError

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

Formats the value using the given formatter.

impl Display for DerivationError

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

Formats the value using the given formatter.

impl Error for DerivationError

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<DerivationError> for Error

fn from(source: DerivationError) -> Self

Converts to this type from the input type.

impl PartialEq for DerivationError

fn eq(&self, other: &DerivationError) -> 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 DerivationError

impl StructuralPartialEq for DerivationError