[ldite]

The dynamic typing and "everything is a map" can be a PITA. At the moment I'm working on a codebase that has I/O to JSON APIs, Avro schemas and postgres databases. That means that a field called "date" can be either a string, integer days since the epoch or a Java Date, and (because this codebase isn't great) there's no way of knowing without tracing the call stack.

With the right discipline (specs, obsessively normalising all data at the boundaries, good naming conventions) this wouldn't have been a problem, but that discipline is optional, and headbanging aggravation results.

(This is, of course, a generic "dynamic typing" problem, but that's a key feature of Clojure)

[flavio81]

>That means that a field called "date" can be either a string, integer days since the epoch or a Java Date, and (because this codebase isn't great) there's no way of knowing without tracing the call stack.

But this is because JSON is an untyped data structure. (And btw, a flawed one...)

You would have this problem in any programming language.

[Capricorn2481]

In other languages you would know which date you were dealing with based on the type regardless of the function you were in. In Clojure, you have to either name the variable date-string or find which API it came from, which means tracing the call stack

[mkreis]

I'd emphasize that it's a problem with your particular code base. If you set it up correctly, all dates are properly parsed at the boundaries and you would only deal with one type of date inside your app. I'm working on a large Clojure app with a lot of date handling and never had any issues. For me, a date is always juxt/tick date.

[ivanb]

The parent comment illustrates the problem with one clear example. In real-world code functions pass around amorphous maps, they add, subtract and transform fields. There is no way to know what's being passed around without reading the source of the whole chain.

Statically typed languages reduce the need to know how the data is structured or manipulated. The market has clearly chosen this benefit over what Clojure can provide.