Struct Overload

pkg/sql/sem/tree/overload.go:43–76

Overload is one of the overloads of a built-in function. Each FunctionDefinition may contain one or more overloads.

// Overload is one of the overloads of a built-in function.
// Each FunctionDefinition may contain one or more overloads.
type Overload struct {
	Types      TypeList
	ReturnType ReturnTyper

	// PreferredOverload determines overload resolution as follows.
	// When multiple overloads are eligible based on types even after all of of
	// the heuristics to pick one have been used, if one of the overloads is a
	// Overload with the `PreferredOverload` flag set to true it can be selected
	// rather than returning a no-such-method error.
	// This should generally be avoided -- avoiding introducing ambiguous
	// overloads in the first place is a much better solution -- and only done
	// after consultation with @knz @nvanbenschoten.
	PreferredOverload bool

	// Info is a description of the function, which is surfaced on the CockroachDB
	// docs site on the "Functions and Operators" page. Descriptions typically use
	// third-person with the function as an implicit subject (e.g. "Calculates
	// infinity"), but should focus more on ease of understanding so other structures
	// might be more appropriate.
	Info string

	AggregateFunc func([]*types.T, *EvalContext, Datums) AggregateFunc
	WindowFunc    func([]*types.T, *EvalContext) WindowFunc
	Fn            func(*EvalContext, Datums) (Datum, error)
	//Generator     GeneratorFactory

	// counter, if non-nil, should be incremented upon successful
	// type check of expressions using this overload.
	//counter telemetry.Counter

	// SpecializedVecBuiltin is used to let the vectorized engine
	// know when an Overload has a specialized vectorized operator.
	SpecializedVecBuiltin SpecializedVectorizedBuiltin
}

// params implements the overloadImpl interface.
func (b Overload) params() TypeList { return b.Types }