* support for custom comparators in LIQ `order by` clauses via the
`using` keyword.
* `using` is mutually exclusive with `asc`/`desc` and accepts either
a *named function* or an *inline anonymous function*. The comparator
receives two values and returns true if the first should come before the
second.
* `nulls first`/ `nulls last` works independently of `using`.
* `using` is now a reserved keyword (`kw`; this cannot be avoided but
the chance to collide with user scripts is negligable),
* documentation updated + polished a little
Signed-off-by: Matouš Jan Fialka <mjf@mjf.cz>
Implements `filter(where <cond>)` for aggregate functions in LIQ
queries which allows per-row conditional filtering within grouped
aggregates. Also extends test suite and documentation.
Signed-off-by: Matouš Jan Fialka <mjf@mjf.cz>
Extend the `order by` clause with optional `nulls first` and `nulls
last` modifiers following standard SQL semantics. Each sort key can
independently specify where `nil` values should appear in the result. By
default, ascending sorts place nulls last and descending sorts place
nulls first. An explicit nulls first or nulls last overrides this
default. The `asc` keyword is also now accepted as an explicit
alternative to the default ascending direction. Documentation and tests
were updated accordingly.
Signed-off-by: Matouš Jan Fialka <mjf@mjf.cz>
* [LIQ] Extend with `group by` and `having` support
Also update documentation with extensive examples and add some parser
tests.
Note: `make generate` JS files included.
Signed-off-by: Matouš Jan Fialka <mjf@mjf.cz>
* Merge `liq-add-support-for-aggregators` branch
Signed-off-by: Matouš Jan Fialka <mjf@mjf.cz>
* Fix link, remove `_` example
Signed-off-by: Matouš Jan Fialka <mjf@mjf.cz>
* Wrap example LIQ queries inside `query [[ .. ]]` and replace `sql` code block type to `lua`
Signed-off-by: Matouš Jan Fialka <mjf@mjf.cz>
* Example self-consistency fix
Signed-off-by: Matouš Jan Fialka <mjf@mjf.cz>
* Fixed some queries
* Add experimental tags to LIQ aggregation/grouping
---------
Signed-off-by: Matouš Jan Fialka <mjf@mjf.cz>
Co-authored-by: Zef Hemel <zef@zef.me>