  We present a spreadsheet implementation, extended with sheet-defined
functions, that allows users to define functions using only standard
spreadsheet concepts such as cells, formulas and references, requiring no new
syntax. This implements an idea proposed by Peyton-Jones and others.
  As the main contribution of this paper, we then show how to add an online
partial evaluator for such sheet-defined functions. The result is a
higher-order functional language that is dynamically typed, in keeping with
spreadsheet traditions, and an interactive platform for function definition and
function specialization.
  We describe an implementation of these ideas, present some performance data
from microbenchmarks, and outline desirable improvements and extensions.

Programming Languages;Software Engineering