LET function

[bacek97]

Wondering if there is any plan in supporting the LET function from Excel and Sheets
https://support.microsoft.com/en-us/office/let-function-34842dd8-b92b-4d3f-b325-b8b8f9908999
https://support.google.com/docs/answer/13190535?hl=en

Think it would be a good supplement to needing to write custom function plugins, and just allow the end user to write formulas they want.

Suppose it has the same problems as the LAMBDA formula, which I am also interested in implementing

[sequba]

Hi @bacek97

At our current stage of development, we prioritize bug and interoperability fixes, so adding new functions is not on our immediate roadmap. If these functions are important to you, the fastest way to make them available in HyperFormula would be via a contribution from the community. I can offer my assistance in the implementation process.

As far as I can tell, implementing both LET and LAMBDA should be possible without major architectural changes to HyperFormula, although it requires using a parser inside the function body, which adds a lot of complexity to the task. Adding these functions as custom functions might require some hacky tricks as parser is not officially exposed as a public API so it will be easier to include them as regular built-in functions.

The main problem with LAMBDA, though, is that even when it's implemented, it cannot be used the way it's intended because HyperFormula does not support parametrized named expressions.