@Override
public Expr optimize(final QueryContext ctx, final VarScope scp) throws QueryException {
final int ar = expr.length - 1;
final Expr f = expr[ar];
final Type t = f.type().type;
if (t instanceof FuncType) {
final FuncType ft = (FuncType) t;
if (ft.args != null && ft.args.length != ar) throw INVARITY.get(info, f, ar);
if (ft.ret != null) type = ft.ret;
}
if (f instanceof XQFunctionExpr) {
// maps can only contain fully evaluated Values, so this is safe
if (allAreValues() && f instanceof Map) return optPre(value(ctx), ctx);
// try to inline the function
if (!(f instanceof FuncItem && comesFrom((FuncItem) f)) && !updating) {
final Expr[] args = Arrays.copyOf(expr, expr.length - 1);
final Expr inl = ((XQFunctionExpr) f).inlineExpr(args, ctx, scp, info);
if (inl != null) return inl;
}
}
return this;
}
/**
* This method creates a step instance.
*
* @param ii input info
* @param a axis
* @param t node test
* @param p predicates
* @return step
*/
public static AxisStep get(final InputInfo ii, final Axis a, final Test t, final Expr... p) {
boolean num = false;
for (final Expr pr : p) num |= pr.type().mayBeNum() || pr.uses(Use.POS);
return num ? new AxisStep(ii, a, t, p) : new IterStep(ii, a, t, p);
}