Description: Currently we have the built in functions, macros, and database data sources. Therefore I'd like to suggest the addition of a new kind of more powerful and generic functions that can serve as a middle ground between all of these. These pure functions would be specified within the data sources view (where currently only database connections are). The main goal of this is to simultaneously reduce the risk current macro solutions have, making them distinct from macros (so that it is easy to differentiate their threat level and access), as well as provide deterministic (cachable result), reusable code and clean (functional programming style and side effect free) implementation of data retrieval and transformation. This also would add a simple way to extend libreoffice calc with user defined functions. These pure functions should be side effect free, be able to make web requests and access only the current document. However before making a web request it should need user approval (or a check against an allow list in the options). This is to allow using a kind of macro without adding all of the risks of macros. These functions should then also be usable to generate a dynamic data source. Such dynamic data sources should also be within the data sources view, and output a table by only using other data sources as well as the formerly mentioned pure functions. These dynamically generated tables should then be accessible from the worksheet. Because we already have the "webservice" function the formerly suggested addition of functions within data sources probably doesn't need any special access handing. However a few more functions could be useful to simplify the creation of both such data sources as well as "just" formulas within normal sheets. These include mostly data transformation ones like: let, map, filter, foldl, foldr, tojson, fromjson, toxml, fromxml, toyml, fromyml, tocsv, fromcsv, webservicerest, try-catch, sha1sum, sha256sum, sha512sum, md5sum, [oauth (with the ability to capture/hook/register/intercept a specific callback url e.g. via embedded browser)], ... Intermediate states of such data sources should be able to contain nested tables as well as errors. To allow for more sophisticated lookups probably also the ability to add an table/sheet from within the current document could prove useful to the data sources registry (this would allow to further lock down the access of such data source functions and tables to only other data sources and prevent them from accessing arbitrary areas of the document that have not been added as a data source themselves beforehand). (the "language" of these data source functions could be an extended version of what we have currently with the normal versions but extended to a "full" functional language. Mainly because that is probably the simplest way to implement it. Alternatively something like a full Scala/Lua/TypeScript/Haskell/F#/... support would also be nice, but esp. the later ones are probably way more difficult to integrate. Especially because most of the utility value of these languages would either vanish when ran within such a restricted environment or add way too much complexity to get it working to begin with.) An alternative implementation of the requested feature would be to fork the current macro system and add a new version of it that does not have access to the system and is limited the same way as outlined above e.g. by putting it into a kind of virtual machine where it can only interact with the outer system through the above mentioned mechanisms (only the document itself and explicitly allowed web endpoints) and thereby be usable without enabling macros and without exposing the system to their "power"/threat. While simultaneously being very useful. Steps to Reproduce: does not apply Actual Results: does not apply Expected Results: does not apply Reproducible: Always User Profile Reset: No Additional Info: Version: 7.6.4.1 (X86_64) / LibreOffice Community Build ID: 60(Build:1) CPU threads: 16; OS: Linux 6.6; UI render: default; VCL: kf5 (cairo+wayland) Locale: en-US (en_US.UTF-8); UI: en-US 7.6.4-2 Calc: threaded