Oh, I think there are great evidences, such as: dialyzer, or ruby3 and python3 shifting towards type signatures everywhere and gradual typing, or recent racket focus on typed racket. Oh, and the rise of typescript of course.
I mean, I've abandoned Python years ago, and I was quite surprised when I discovered python people are adding type annotations everywhere.
Sure, gradual typing is not a strictly enforced as in statically typed languages, but seems people are agree that modularity and abstraction without type signatures is painful in sufficiently large programs.
I don’t feel like this anecdote is evidence because I don’t think it’s inconsistent with the trend towards more static types over the last 5-10 years or so. For this anecdote to be convincing I would need to think that programming language design happens because of carefully thought out and researched decisions and quick feedback as good languages are used and bad languages are dropped, but I don’t believe this.
Yes, this is not a sound rigid empirical proof, it's an observation (i.e. unlike the case of anecdotal, you can measure the marketshare of user, how many do use dialyzer or typescript, etc etc). We can't simply ignore any observations that are not scientifically rigid, otherwise the whole edifice of philosophy or even some natural sciences should simply perish.
I don't think you can just omit that. I'm a fan of Lakatos here, if I have some observation, I think one need at least as convincing evidence or more rigid one to prove otherwise.
> because of carefully thought out and researched decisions
I think it's a better evidence exactly because it's what language users are asking about, and what large chunk of language users choose to use when they got a choice. This shows that quite a big share if not majority of programmers value type annotations.
To be clear, this is where I disagree. I don’t want to claim that people don’t think hard about language design or that users aren’t asking for these features as I think both of those statements are true. But I strongly disagree that languages doing things (and those languages being popular) is good evidence that those things are good.
I think a lot of language design is driven by fashion (ie keeping up with what similar languages are doing) and I claim that this is a more convincing reason for python having some gradual typing.
I think large number of people is moving to/from from python for gradual typing in aggregate, and I don’t think it’s happening on the margin either. I think any wise decisions about languages are more likely to be driven by practical considerations (what do people know, what are they used to, what can people be hired for, what libraries are available, what platforms are supported, what performance is required, and so on).
Just because python has a large market share, it doesn’t mean it’s users are supporters of gradual typing, it just means that they thought python was a good idea when they first started using it and they haven’t justified the cost of changing to something else. The users didn’t choose gradual typing they just chose “upgrade the language to the next version”
Even if I agreed with your claim that many users asked for gradual typing, I don’t agree that in aggregate users ask for things that will be good for them or good in general. Maybe users are just trying to figure out a way to say “we want our programs to be less buggy” and think this might help. I think there are better examples in programming language design of what can happen if you keep giving users what they are asking for.
In my opinion dynamic programmers need to embrace the runtime environment and use it as part of their development methodology. Unfortunately most popular dynamic languages have woeful runtime environments.
dynamic languages (like smalltalk) were designed for live coding where the results are immediate, when that is broken and coding is done in a "dead" environment of course dynamic typing will cause problems that arent caught until runtime... but the original idea was one shouldnt have had to wait until runtime in the first place!
Any others?
Unfortunately the same amount of effort that has been applied to static type checking has not been applied to dynamic language environments.
It would have been very interesting to see what could be possible with the more advancement.
For the amount people care about it, there isn’t much evidence in either direction. And most studies that do exist are limited to small programs typically written by novices. Yale’s Singapore campus are going to be running two instances of the same course in parallel soon, one in python and one in ocaml. Perhaps that will provide a datapoint about learning the languages but maybe there will just be a lot of selection bias or library or environment or teacher differences. And how easy it is to learn a language probably isn’t the main datapoint to care about anyway.