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Discussion on: Programming Paradigms and the Procedural Paradox

 
gaverhae profile image
Gary Verhaegen

void and unit are generally type names, not values. My point was, even though some languages are syntactically defined such that everything is an expression and there is technically no statement in the language, there are still expressions that do not return any useful value. Clojure and Ruby would be examples of that.

Once static typing gets involved, the compiler may actively prevent using the return value of a void function, but that's a different story.

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kspeakman profile image
Kasey Speakman • Edited

Here is a good post on void vs unit. Unit does in fact have a value and a type, unlike void. Otherwise I agree with you. Prime example of what you are saying in F#: when a function returns unit (which is a sign that it performs a side effect), and it contains an if statement, then the compiler will include an implicit else () if you don't supply one. I actually don't like that, because it hindered my understanding when I was first learning F#. The early things you do like printing to the console return unit, so it feels like if is a statement. But then later when you are doing other kinds of logic, it won't compile when you operate under that assumption.