Hi guys,
first, congrats on Groovy 6.0.0 G-)
We are still on Groovy 4 (kind of dreading what IntelliJ Intellisense
will do with a newer Groovy version, given how much code it incorrectly
marks as "erronous" now), and I finally found the time to do a quick
spike to create an early-out null-mapping macro, which tests only for
!== null (no Groovy truth, because in 99% of cases that is not what we
want) and takes an arbitrary number of arguments:
Examples:
final x = NULL_TO(x0(),x1(),x2(),x3(),x4()) // same as ternary/Elvis
operator, x1(),etc is only evaluated, if x0() evaluates to null, etc
final sqe = NULL_TO(sqlExecutorIn, Global.sqe, createSqlExecutor()) //
again, createSqlExecutor() is only called iff sqlExecutorIn and
Global.sqe are both null
Macro stub:
static <T> T NULL_TO(T... args) { ... }
This works fine, the only problem is, that under static compilation the
resulting return type of NULL_TO always seems to be Object (instead of
generic type T), so I have to use an explicit type cast in these cases,
which is decidedly un-Groovy.
Examples:
// If x0(), etc all have return type BigDecimal, fails later on when
trying to use BigDecimal functionality on x under @CompileStatic without
the cast
final x = (BigDecimal) NULL_TO(x0(),x1(),x2(),x3(),x4())
// Fails with "Object cannot be assigned to SqlExecutor" under
@CompileStatic otherwise
final SqlExecutor sqe = (SqlExecutor) NULL_TO(sqlExecutorIn, Global.sqe,
createSqlExecutor())
Comparing this to the existing named value macros, it seems return types
only work if they are given explicitly, but not when they are
generics... (?)
Is there a way to fix/improve this and avoid the cast (or equivalent "as
...") ? Was this improved in newer Grooyv versions (I searched the
Groovy Jira, but found nothing in the very small number of tickets that
has "macro" in their summary) ?
Thanks, cheers,
mg
