Enum QueryError 

pub enum QueryError {
    Syntax(String),
    Semantic(String),
    Type(String),
    Graph(GraphError),
    UnboundVariable(String),
    MissingParam(String),
    Cancelled,
    Timeout,
    ResourceLimit(String),
}

Typed error taxonomy, in three tiers that reflect when the problem was knowable:

• Syntax: the query text itself is malformed — never reached planning/execution at all (parser.rs, including pest’s own grammar failures).
• Semantic: the query text parsed fine but describes something structurally invalid — knowable from the query alone, no data/parameters needed (an unsupported pattern shape, an aggregate nested somewhere it can’t be, EXPLAIN EXPLAIN, …).
• Type: only knowable once a real value (from stored data or a $parameter) is in hand and turns out to be the wrong shape (arithmetic on a non-number, indexing a non-list, a date({...}) field of the wrong type, …).

Callers that only need “did it work” (most of this codebase) keep using Display/? as before — this tiering exists for callers that want to react differently to “you wrote something illegal” vs “the data didn’t match what the query assumed” (an application surfacing user-facing messages, or ExecutionOutcome’s telemetry categories).

Variants

Syntax(String)

Semantic(String)

Type(String)

Graph(GraphError)

UnboundVariable(String)

MissingParam(String)

Cancelled

Timeout

ResourceLimit(String)

Trait Implementations

impl Debug for QueryError

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

Formats the value using the given formatter.

impl Display for QueryError

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

Formats the value using the given formatter.

impl Error for QueryError

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<GraphError> for QueryError

fn from(source: GraphError) -> Self

Converts to this type from the input type.