4 ms·

That is indeed very handy, but I would argue that there's a difference between running a program in a debugger and running it normally. With regards to the res

That is indeed very handy, but I would argue that there's a difference between running a program in a debugger and running it normally. With regards to the rest of your post: macros and data-as-code. Have you read this http://www.paulgraham.com/diff.html http://www.paulgraham.com/diff.html ?

Groxx 13y ago
"What Made Lisp Different" - all true. All intended as past tense. I never see claims that Lisp is unique because it has GC, for instance. Looking at the 'setf' macro, since you have to use 'defsetf', I don't see the difference between that and something in Ruby where you could do (errors aside): class Object def defsetf(name) $setf[self.class] = name end end def setf(class, *args) class.send($setf[class], *args) end class Whatever defsetf :set_something def set_something; end end # elsewhere... setf Whatever, instance, value Adding arbitrarily-complex ways to let you specify how to transform the arguments to a call is as easy as accepting a lambda instead of a symbol, recursive setf-ing[1] is just a lookup on the arguments and then nesting lambdas. I might be missing some deeper realization here though - defsetf seems pretty simple. Certainly the use could be complex, but I see nothing that implies that its implementation is unachievable, even with nearly-identical syntax, so what remains is library support and community. Again - specialization, not unique attribute of the language. As to "data-as-code", I think you mean the other way around? If not, eval. If yes, Ruby's reflection is I think insufficient without heavy modification like e.g. running a ruby interpreter in ruby to read its own source code and "reflect" with the AST that generates (though this is possible[2]). This is one spot where Lisp-likes certainly excel to a degree few outsiders achieve, but I'm sure I've seen outsiders, they're just not as fluent or efficient at running it. But few outsiders have real interest in optimizing it, or people label them as yet another Lisp-like, making the point sort of moot since it's part of the definition of being Lisp-like (to many). -- Macros in particular come up often, but I don't see anything really interesting about them. If you have the full AST available (a rarity, I'll admit), then it seems like a strict subset of runtime modification - it's just a self-eliminating runtime modification, done ahead of time for speed purposes. Except for maybe C-style macros, which (via a horrible syntax) can generate anything, not just valid code, which isn't always possible. [1]: (setf (sqrt something) number) => (set-sqrt something number) => (setf something (* number number)) in here: http://lists.warhead.org.uk/pipermail/iwe/2005-July/000130.html http://lists.warhead.org.uk/pipermail/iwe/2005-July/000130.h... found via here: http://stackoverflow.com/questions/267862/what-makes-lisp-macros-so-special http://stackoverflow.com/questions/267862/what-makes-lisp-ma... [2]: https://www.ruby-forum.com/topic/1108988 https://www.ruby-forum.com/topic/1108988
- lispm 13y ago
  SETF is a macro. The setter will be computed at macro expansion time - for example if one compiles code.
- lispm 13y ago
  > Macros in particular come up often, but I don't see anything really interesting about them. Well, the experience of most advanced Lisp uses is totally different.

Groxx 13y ago

"What Made Lisp Different" - all true. All intended as past tense. I never see claims that Lisp is unique because it has GC, for instance. Looking at the 'setf' macro, since you have to use 'defsetf', I don't see the difference between that and something in Ruby where you could do (errors aside): class Object def defsetf(name) $setf[self.class] = name end end def setf(class, *args) class.send($setf[class], *args) end class Whatever defsetf :set_something def set_something; end end # elsewhere... setf Whatever, instance, value Adding arbitrarily-complex ways to let you specify how to transform the arguments to a call is as easy as accepting a lambda instead of a symbol, recursive setf-ing[1] is just a lookup on the arguments and then nesting lambdas. I might be missing some deeper realization here though - defsetf seems pretty simple. Certainly the use could be complex, but I see nothing that implies that its implementation is unachievable, even with nearly-identical syntax, so what remains is library support and community. Again - specialization, not unique attribute of the language. As to "data-as-code", I think you mean the other way around? If not, eval. If yes, Ruby's reflection is I think insufficient without heavy modification like e.g. running a ruby interpreter in ruby to read its own source code and "reflect" with the AST that generates (though this is possible[2]). This is one spot where Lisp-likes certainly excel to a degree few outsiders achieve, but I'm sure I've seen outsiders, they're just not as fluent or efficient at running it. But few outsiders have real interest in optimizing it, or people label them as yet another Lisp-like, making the point sort of moot since it's part of the definition of being Lisp-like (to many). -- Macros in particular come up often, but I don't see anything really interesting about them. If you have the full AST available (a rarity, I'll admit), then it seems like a strict subset of runtime modification - it's just a self-eliminating runtime modification, done ahead of time for speed purposes. Except for maybe C-style macros, which (via a horrible syntax) can generate anything, not just valid code, which isn't always possible. [1]: (setf (sqrt something) number) => (set-sqrt something number) => (setf something (* number number)) in here: http://lists.warhead.org.uk/pipermail/iwe/2005-July/000130.html http://lists.warhead.org.uk/pipermail/iwe/2005-July/000130.h... found via here: http://stackoverflow.com/questions/267862/what-makes-lisp-macros-so-special http://stackoverflow.com/questions/267862/what-makes-lisp-ma... [2]: https://www.ruby-forum.com/topic/1108988 https://www.ruby-forum.com/topic/1108988

lispm 13y ago
SETF is a macro. The setter will be computed at macro expansion time - for example if one compiles code.
lispm 13y ago
> Macros in particular come up often, but I don't see anything really interesting about them. Well, the experience of most advanced Lisp uses is totally different.