Function arrayconst_startup_fn

src/backend/optimizer/util/predtest.c:964–1011

} ArrayConstIterState;

static void
arrayconst_startup_fn(Node *clause, PredIterInfo info)
{
	ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
	ArrayConstIterState *state;
	Const	   *arrayconst;
	ArrayType  *arrayval;
	int16		elmlen;
	bool		elmbyval;
	char		elmalign;

	/* Create working state struct */
	state = (ArrayConstIterState *) palloc(sizeof(ArrayConstIterState));
	info->state = (void *) state;

	/* Deconstruct the array literal */
	arrayconst = (Const *) lsecond(saop->args);
	arrayval = DatumGetArrayTypeP(arrayconst->constvalue);
	get_typlenbyvalalign(ARR_ELEMTYPE(arrayval),
						 &elmlen, &elmbyval, &elmalign);
	deconstruct_array(arrayval,
					  ARR_ELEMTYPE(arrayval),
					  elmlen, elmbyval, elmalign,
					  &state->elem_values, &state->elem_nulls,
					  &state->num_elems);

	/* Set up a dummy OpExpr to return as the per-item node */
	state->opexpr.xpr.type = T_OpExpr;
	state->opexpr.opno = saop->opno;
	state->opexpr.opfuncid = saop->opfuncid;
	state->opexpr.opresulttype = BOOLOID;
	state->opexpr.opretset = false;
	state->opexpr.opcollid = InvalidOid;
	state->opexpr.inputcollid = saop->inputcollid;
	state->opexpr.args = list_copy(saop->args);

	/* Set up a dummy Const node to hold the per-element values */
	state->constexpr.xpr.type = T_Const;
	state->constexpr.consttype = ARR_ELEMTYPE(arrayval);
	state->constexpr.consttypmod = -1;
	state->constexpr.constcollid = arrayconst->constcollid;
	state->constexpr.constlen = elmlen;
	state->constexpr.constbyval = elmbyval;
	lsecond(state->opexpr.args) = &state->constexpr;

	/* Initialize iteration state */
	state->next_elem = 0;
}

static Node *
arrayconst_next_fn(PredIterInfo info)