/**
* Returns a new tuple by renaming some attributes.
*
* <p>Note: despite its visibility, this method is part of JAlf protected API. It should not be
* used by end users. TODO: how to fix this without hurting performance too much?
*
* @param r renaming function mapping old to new attribute names.
* @pre `resultingType` should be faithful to the actual result, that it it must guarantee the
* post condition.
* @return the renamed tuple.
* @post `resultingType.contains(rename(r, resultingType))` is true
*/
public Tuple rename(Renaming r, TupleType resultingType) {
return new Tuple(resultingType, rekey(attrs, (k, v) -> r.apply(k)));
}
@Test
public void testItSupportsSuffixRenaming() {
Renaming r = Renaming.suffix("foo");
assertEquals(r.apply(sid), attr("sidfoo"));
}
@Test
public void testItSupportsPrefixRenaming() {
Renaming r = Renaming.prefix("foo");
assertEquals(r.apply(sid), attr("foosid"));
}
@Test
public void testItSupportsIntensionRenaming() {
AttrName SID = attr("SID");
Renaming r = Renaming.intension(a -> attr(a.getName().toUpperCase()));
assertEquals(r.apply(sid), SID);
}
@Test
public void testExtensionRenamingIsTotal() {
Renaming r = Renaming.extension(sid, ssid, name, sname);
assertEquals(r.apply(city), city);
}
@Test
public void testItSupportsExtensionRenaming() {
Renaming r = Renaming.extension(sid, ssid, name, sname);
assertEquals(r.apply(sid), ssid);
assertEquals(r.apply(name), sname);
}
