
Simon Peyton Jones – Elastic sheet-defined functions [video] - vanderZwan
https://www.youtube.com/watch?v=jH2Je6wUvPs
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vanderZwan
For those more interested in reading than watching a video, here is the
detailed 67-page paper about this subject that was recently accepted for
publication:

 _Elastic Sheet-Defined Functions: Generalising Spreadsheet Functions to
Variable-Size Input Arrays_

 _Sheet-defined functions (SDFs) bring modularity and abstraction to the world
of spreadsheets. Alas, end users naturally write SDFs that work over fixed-
size arrays, which limits their re-usability. To help end user programmers
write more re-usable SDFs, we describe a principled approach to generalising
such functions to become elastic SDFs that work over inputs of arbitrary
size._

 _We prove that under natural, checkable conditions our algorithm returns the
principal generalisation of an input SDF. We describe a formal semantics and
several efficient implementation strategies for elastic SDFs._

 _A user study with spreadsheet users compares the human experience of
programming with elastic SDFs to the alternative of relying on array
processing combinators. Our user study finds that the cognitive load of
elastic SDFs is lower than for SDFs with map /reduce array combinators, the
closest alternative solution._

[https://www.microsoft.com/en-
us/research/publication/elastic...](https://www.microsoft.com/en-
us/research/publication/elastic-sheet-defined-functions-generalising-
spreadsheet-functions-to-variable-size-input-arrays/)

