Type Systems Explained with Examples

In Assembly, there is no cow, no mooing, there's a bunch of places where parts of cows and moos may or may not be stored. It's up to you to pick the parts of the cows and moos in the correct order, then send the numbers representing the places where the cow and moo parts are stored to a magic box that interprets your sequence of numbers and puts the cow into the correct order after which you jump over to the cow and tickle its belly until it moos.

So what's the difference between ruby and python?

In ML, it's inferred if it might, in any potential future, moo.

But only clones on write, which is a useful optimization.

What do you think "duck typing" is? Historically, it feels like I've mostly heard the term applied to Python.

Edited to add: Please don't take my question as rhetorical attack - it was intended as inquiry. There may be different definitions floating around.

You mean https://github.com/moonad/Moonad ?

Having watched both, I believe the parent comment meant the talk they linked. The first 20 minutes has some talk about representation and type and meaning.

Both talks are interesting. Both are from a very C++ perspective, particularly the one you suggest. That doesn't make them wrong, by any means. Much of it generalizes, although depending on your background it might take varying amounts of effort to understand the generalizations.

In the first talk in particular, I think he conflates (in a small way) type with representation in a way that's... not... ideal? But I don't think it does a lot of harm to the talk; he has very interesting things to say particularly about representation.

Some of the point of both talks overlaps with the common admonishment to "make illegal states unrepresentable", but I don't think any fully implies the other.

For a very different perspective on types, I highly recommend watching https://www.youtube.com/watch?v=3U3lV5VPmOU, although I don't highly recommend actually programming this way.

Found an interesting paper on this!

https://www.tandfonline.com/doi/pdf/10.1080/00437956.2007.11...

"The morphology of English words like dependence, linguistics, and news suggests that English has an /-s/ suffix forming certain kinds of abstract nouns not used as plurals. While dependence and dependents are homophones, the former takes singular verb agreement, as do linguistics and news, and the latter takes plural. We argue that English has a highly productive derivational suffix /-s/ that creates abstract nouns from adjectives, dependence from dependent + /-s/, linguistics from linguistic + /-s/, and news from new + /-s/. While this suffix originated in the Latin present participle, the sources of a modern /-s/ came into English through extensive borrowing from Latin and French as well as through loan translation and borrowing of Greek words, but then it combined with existing English /-s/ that marked plural or genitive. Orthographic, phonological, morphological, and semantic evidence suggests that this modern /-s/ arose from several distinct sources that came together as a single suffix in the early 171h century."