Enum EvalError 

#[non_exhaustive]
pub enum EvalError {
    UndefinedVariable(String),
    InvalidPath(String),
    TypeError {
        expected: &'static str,
        got: String,
    },
    CommandFailed(String),
    NoExecutor,
    ArithmeticError(String),
    RegexError(String),
    Unsupported(String),
}

Errors that can occur during expression evaluation.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

UndefinedVariable(String)

Variable not found in scope.

InvalidPath(String)

Path resolution failed (bad field/index access).

TypeError

Type mismatch for operation.

Fields

expected: &'static str

got: String

CommandFailed(String)

Command substitution failed.

NoExecutor

A node that only the async evaluator can handle (command substitution, or a command used as a condition) reached the sync evaluator, which has no way to execute pipelines. Unreachable in practice — the kernel resolves these to literals first — but loud rather than silently empty.

ArithmeticError(String)

Division by zero or similar arithmetic error.

RegexError(String)

Invalid regex pattern.

Unsupported(String)

A collection (list/record) was compared to a scalar with ==/!=, or a collection form (${#…}, ${…:-default}) was used on a subscripted path before that path support landed. Carries a full teaching message.

Trait Implementations

impl Clone for EvalError

fn clone(&self) -> EvalError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for EvalError

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

Formats the value using the given formatter.

impl Display for EvalError

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

Formats the value using the given formatter.

impl Error for EvalError

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 PartialEq for EvalError

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for EvalError