Method Eval

pkg/sql/sem/tree/eval.go:3928–3965

Eval implements the TypedExpr interface.

(ctx *EvalContext)

// Eval implements the TypedExpr interface.
func (expr *IndirectionExpr) Eval(ctx *EvalContext) (Datum, error) {
	var subscriptIdx int
	for i, t := range expr.Indirection {
		if t.Slice || i > 0 {
			return nil, errors.AssertionFailedf("unsupported feature should have been rejected during planning")
		}

		d, err := t.Begin.(TypedExpr).Eval(ctx)
		if err != nil {
			return nil, err
		}
		if d == DNull {
			return d, nil
		}
		subscriptIdx = int(MustBeDInt(d))
	}

	d, err := expr.Expr.(TypedExpr).Eval(ctx)
	if err != nil {
		return nil, err
	}
	if d == DNull {
		return d, nil
	}

	// Index into the DArray, using 1-indexing.
	arr := MustBeDArray(d)

	// VECTOR types use 0-indexing.
	switch arr.customOid {
	case oid.T_oidvector, oid.T_int2vector:
		subscriptIdx++
	}
	if subscriptIdx < 1 || subscriptIdx > arr.Len() {
		return DNull, nil
	}
	return arr.Array[subscriptIdx-1], nil
}

// Eval implements the TypedExpr interface.
func (expr *CollateExpr) Eval(ctx *EvalContext) (Datum, error) {