Talk:List comprehensions: Difference between revisions

:'''Problem''' – Not only was the number of eligible languages diminished by the slippage from task toward surface notation, but the scope for contrastive insight was also reduced. What is interesting about the definition and population of sets is that it can be done in various ways – for example with a monadic 'do' notation, with iteration, with structured recursion, etc. Ironically, the list comprehension notation, which is never part of core syntax, actually happens to conceal the variation in what is really going on in different languages. Python's list comprehensions are implemented, under the hood, as for loops (see http://morepypy.blogspot.co.uk/2008/06/list-comprehension-implementation.html) while Haskell's are syntactic sugar for a 'do' notation which in turn desugars down to lambda applications. (see http://www.haskellforall.com/2014/10/how-to-desugar-haskell-code.html).

:'''Solution''' – Understandable distraction away from the underlying concepts (and core editorial values) by what was, at the time, a novel notation, could have been mitigated by a discipline of stepping through Rosetta's 3 core goals, using them both as a kind of check-list, and as a stimulus to raising the game, and reflecting a little harder both on what the underlying issues really were, what list comprehensions really were (useful syntactic sugar for deeper processes in the core syntax of particular languages) and on what it would take to reach the largest number of languages, and the deepest and most useful levels of contrast, comparison and comparisoninsight.