@Test
public void testExtensionRenamingIsReversible() {
Renaming r = Renaming.extension(sid, ssid, name, sname);
assertTrue(r.isReversible());
Renaming reverse = Renaming.extension(ssid, sid, sname, name);
assertEquals(reverse, r.reverse());
}
@Test
public void testProjectOnExtension() {
Renaming r = Renaming.extension(sid, ssid, name, sname);
Renaming expected = Renaming.extension(name, sname);
// it works with a subset of original attributes
AttrList list = AttrList.attrs(name);
Renaming got = r.project(list);
assertEquals(expected, got);
// it is robust to a superset too (city was not part of it)
list = AttrList.attrs(name, city);
got = r.project(list);
assertEquals(expected, got);
}
/**
* 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 testSuffixRenamingIsReversible() {
Renaming r = Renaming.suffix("foo");
assertTrue(r.isReversible());
assertEquals(attr("sid"), r.reverse().apply(attr("sidfoo")));
}
@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);
}
