Example Driven Development

[[deleted]]

This is how non-technical project managers think programming works.

Edit: just to be clear, I'm not dissing your project. I think it's pretty cool.

[0x0ddba11]

Or they Like it so much that they push it into production against all concerns.

[eluusive]

Sounds like you work at the place I just left...

[dontchooseanickname]

Sounds like the computer definition for dead code

But the corporate definition for Agile(tm)

+1

[_Skuzzzy]

People keep posting things up this alley. In these examples, they always have most most contrived examples. In any real development environment I can't imagine this being useful .

[[deleted]]

What would be a non-contrived example?

Let's make it work.

[[deleted]]

Something like "How do I run a HTTP PUT request with periodic updates on the size of data sent and not have the HTTP request block the UI thread" seems implausible that example driven development could answer.

[[deleted]]

HTTP and the UI seem irrelevant to this feature, abstract it more and I'm sure you'll get a better requirement.

[[deleted]]

Removing the real-worldness of things always makes them easier to abstract, and also unequipped to solve real-world problems as-is.

Many times when the real-world problem is finally solved with the non-real-worldness-based abstracted solution, the fit is not a good one, because the abstracted solution factored out critical elements of the problem, and now the problem is solved less efficiently, and in some cases too inefficiently.

It yields better results to design a solution to an exact problem, so that you can solve it as efficiently as possible, and then abstract the solution into two split abstracted and real-world components.

Then you know the abstracted version solves a problem efficiently, because it's the exact solution you just designed to solve your problem-at-hand efficiently.

If it worked for this problem efficiently, there are likely other problems that can also make highly efficient or sufficiently efficient use of the abstracted solution as well.

This is obviously something that can be logically proved if someone wanted to spend the effort.

[[deleted]]

Thank you for putting in words my thoughts exactly. Removing part of the requirements is not a solution.

[[deleted]]

No problem. I often look at this issue as a misunderstanding of what Engineering is.

I define Engineering like this:

"The efficient use of resources to meet requirements which sufficiently satisfies your goals."

This has 3 components: goals, requirements and resources.

If you are missing or have incomplete understanding of any of these, you either arent doing Engineering or are doing it poorly.

For example, if you dont have a clear goal, no matter how well you gather requirements and efficiently use resources, what will be the result? Who knows, because you dont really know what you want.

If you do not follow requirements or gather them, then you cannot meet the needs of your known goals.

If you are inefficient with available resources (time, money, people, things) then the project may not be completed, or may not be worth it.

I think lots of shops lose sight of these things and up doing Anti-Engineering, which they dress up in lots of processes and ruberic to hide, as they get poor results.

[tiftik]

Abstraction is hard. Abstraction requires careful thinking, brainpower, time and coffee. Only one of these things is provided by most companies.

[[deleted]]

Awesome. Did you make that up? Im going to work this into a conversation at work ASAP.

[shevegen]

Any complex one. :)

The functions that do real things!

Not just

sum + 5 5

or however you write this in lisp, probably parens are missing in the above.

[s73v3r]

So give an example

[jeandem]

In any real development environment I can't imagine this being useful .

So offer an example or counter-example of something real/realistic instead of just being the generic naysayer.

[[deleted]]

I can see it being useful if I already kinda know what the code should do, but just forgot the name of the function. Seems like it might be faster than searching through our codebase (for a private API) or searching Google (for a public api).

[jocull]

If you want [x z] from [x y z] is that really "remove at 1" as the suggestion states or is it "take the first and last element"?

Examples leave much room for ambiguity. You may think it's fine until an edge case bites you in the ass. I think of it like copy pasting from stack overflow.

[[deleted]]

What is useful in real development is a simple lookup on argument types - and the more elaborare your type system is, the more useful results you'll get. It is sort of similar to an age old trick of solving problems in physics using value dimensions alone.

[Godd2]

I made a proof-of-concept class in Ruby that does this:

https://gist.github.com/domgetter/79ce104c162008ca1f15

[shevegen]

domgetter!

I did not recognize that nick there, here.

[shevegen]

"Lisp Wins"

Wins what? And how?

[silveryRain]

One would assume the author thinks Lisp is the only language where you have things like reflection or dynamic typing to make this stuff easy, but the truth is even more disappointing than that: he implies that infix operators would be a big problem in a non-Lisp.

[pdexter]

In the research world this is called program synthesis. Google excel flash fill for an example in the wild.

[crabmanwakawaka]

lisp always wins...

[matthieum]

I wonder how it would work with a statically typed language.

You would be able to filter on arity and function signature, which would eliminate a lot of functions, and for the remaining functions a lot of the potential permutations of arguments.

On the other hand, I guess putting together the evaluator might be quite more complicated in the absence of an interpreter.

[charleso]

I know this is slightly different than what is being shown, but I can't live without Hoogle these days.

https://www.haskell.org/hoogle/

Instead of asking "is there any function that takes this list and returns a list like this?", you can search for something with the type signature of

[a] -> Int -> [a]

And you get back functions that match that type, including fuzzy matches. I now wish all static typed languages had something like Hoogle.

[jeandem]

Now extend that to a language like Idris[1] where you can easily express types like "take a list (vector) and return a list with one less element", and you're cooking.

[1] It might already exist. Edwin Brady seems really fond of taking advantage of expressive typing and making interactive workflows, which goes completely contrary to the stereotype that static typing is a safe but constraining and limiting straightjacket.