Enum DiffError 

pub enum DiffError {
    NotImplemented(String),
    InvalidMarker(String),
    AmbiguousColumn(String),
    ProjectionBoundary(String),
    Parse(String),
    Internal(String),
}

An error produced while differentiating or rewriting SQL.

Every failure mode of ddx-core is one of these. In keeping with design principle 5 — fail loud, never silently wrong (design.md §2) — an unsupported construct is always one of these typed errors, never an approximate or silently-zero derivative.

Variants

NotImplemented(String)

A node or function has no differentiation rule. This is the “permanent or roadmap” bucket: atan2 (no rule yet), general u^v, CASE, comparisons, string/temporal expressions (design.md §3.6).

InvalidMarker(String)

The wrt (or a marker call) is malformed: wrt is not a bare column, wrong argument count, etc.

AmbiguousColumn(String)

An occurrence of the wrt base name could not be pinned syntactically — a bare occurrence when wrt is qualified, or a qualified occurrence when wrt is bare. Hard error demanding full qualification (design.md §3.2, F2).

ProjectionBoundary(String)

A marker argument references an identifier that is a computed select-list alias of a CTE/derived table in the same statement, used as a non-wrt term — differentiation would silently drop terms across the projection boundary (design.md §3.5, F3/G4).

Parse(String)

The input SQL did not parse under the given dialect. Only ever reported for a statement that contains a marker (the parse-free pre-gate means marker-free statements are never parsed, design.md §3.2, F5).

Internal(String)

An internal invariant was violated (e.g. an empty source span the API documents as possible, with no safe fallback). Should not occur in normal use.

Trait Implementations

impl Clone for DiffError

fn clone(&self) -> DiffError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DiffError

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

Formats the value using the given formatter.

impl Display for DiffError

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

Formats the value using the given formatter.

impl Eq for DiffError

impl Error for DiffError

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 DiffError

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for DiffError