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> That said, Common Lisp is weird. What I find particularly jarring is that functions and variables live in different namespaces: if you put a function into a v

> That said, Common Lisp is weird. What I find particularly jarring is that functions and variables live in different namespaces: if you put a function into a variable, you can’t just use it like a function, you have to funcall it. Unless I’m misunderstanding, the author sounds like a developer that’s primarily used JS. It’s really not abnormal to have to include parens after a method name in a language, which indicating that you are calling a function.

blockmeifyoucan 6y ago
I think you are misunderstanding. In common Lisp you can call a regular function defined with defun as (foo "something"), but if bar is a variable containing a fuction you have to use (funcall bar " something"). I agree that this is weird and confusing.
- kame3d 6y ago
  Isn't that the same thing as using function pointers in C? You need the * to access the function the variable points to.
  - eigenspace 6y ago
    Sure, this isn't that rare of a thing for languages, but it is increasingly rare to find people who think this is a good idea.
  - oalae5niMiel7qu 6y ago
    No you don't. You call the pointer itself. It points to the first instruction in the function. It's more like Ruby's method(:foo) and .call().
shakow 6y ago
> It’s really not abnormal to have to include parens after a method name in a language That's not what he means. Assuming some pseudocode with a more common syntax to prune the parentheses question, Common lisp is doing this: function f(x) { print(x) } let a = f funcall(a)(27) # prints 27 Whereas Scheme is doing this: function f(x) { print(x) } let a = f a(27) # also prints 27 This is the fundamental difference between so-called Lisp-1 and Lisp-2 families, depending on whether functions and variable share the same namespace or if they have to be “lifted” from one to another through funcall.

blockmeifyoucan 6y ago

I think you are misunderstanding. In common Lisp you can call a regular function defined with defun as (foo "something"), but if bar is a variable containing a fuction you have to use (funcall bar " something"). I agree that this is weird and confusing.

kame3d 6y ago
Isn't that the same thing as using function pointers in C? You need the * to access the function the variable points to.
- eigenspace 6y ago
  Sure, this isn't that rare of a thing for languages, but it is increasingly rare to find people who think this is a good idea.
- oalae5niMiel7qu 6y ago
  No you don't. You call the pointer itself. It points to the first instruction in the function. It's more like Ruby's method(:foo) and .call().

shakow 6y ago

> It’s really not abnormal to have to include parens after a method name in a language That's not what he means. Assuming some pseudocode with a more common syntax to prune the parentheses question, Common lisp is doing this: function f(x) { print(x) } let a = f funcall(a)(27) # prints 27 Whereas Scheme is doing this: function f(x) { print(x) } let a = f a(27) # also prints 27 This is the fundamental difference between so-called Lisp-1 and Lisp-2 families, depending on whether functions and variable share the same namespace or if they have to be “lifted” from one to another through funcall.