Enum ExpandError 

#[non_exhaustive]
pub enum ExpandError {
    VariableNotFound {
        name: String,
    },
    MaxDepthExceeded {
        depth: u32,
        expr: String,
    },
    MalformedExpression {
        expr: String,
    },
}

Error when expanding DNF variables fails.

Covers three failure modes: a variable name not found in the substitution map, exceeding the maximum recursion depth (default 32), and malformed variable expression syntax.

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.

VariableNotFound

A variable referenced in the input string was not found in the substitution map.

Fields

name: String

The name of the missing variable.

MaxDepthExceeded

The maximum recursion depth was exceeded while expanding a variable expression (likely a circular reference).

Fields

depth: u32

The depth at which expansion stopped.

expr: String

The expression being expanded when the limit was hit.

MalformedExpression

A variable expression has invalid syntax (e.g., an empty $ without a following name).

Fields

expr: String

The invalid expression text.

Trait Implementations

impl Debug for ExpandError

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

Formats the value using the given formatter.

impl Display for ExpandError

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

Formats the value using the given formatter.

impl Error for ExpandError

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.