4 ms·

When we look at Lisp we see archaic user interfaces, legacy keywords such as car, cdr and cons which bear no meaning to us mere mortals. Also no clear consensus

When we look at Lisp we see archaic user interfaces, legacy keywords such as car, cdr and cons which bear no meaning to us mere mortals. Also no clear consensus on what extensions to use. Why are there so many dialects? Can you not agree on something that works? Where is your IDE with error underlining and autocomplete list that comes up with each keystroke? And finally s-expressions, which make you twist your mind in order to write and don't give clear structure of the code meaning to the reader, and not even considering macros... Not trying to start an argument, but that's my view from a C#'er who tried Lisp a while ago. I often see Lisp talked about on HN as though it's the solution to all our problems, but it's really not. Syntax is a big deal in programming languages, with lots of trade offs between human readability and unambiguous parsing by the computer, and s-exps aren't some magic bullet for this.

lispm 11y ago
> Why are there so many dialects? That's a really funny question in a thread about another new programming language.
davexunit 11y ago
>When we look at Lisp we see archaic user interfaces, legacy keywords such as car, cdr and cons which bear no meaning to us mere mortals. Also no clear consensus on what extensions to use. Car, cdr, and cons take very little time to understand, but yes their meaning is steeped in history. "car" returns the first element of a pair, "cdr" (pronounced like "could-er") returns the second element of a pair, and "cons" creates pairs. Not that bad. However, today's Lisps put more emphasis on using pattern matchers than manually car/cdring down lists. >Why are there so many dialects? That's like asking "Why are there so many ALGOL derivatives?" Lisp classifies a family of languages, not a single language. It's like saying something has C-like syntax. >Can you not agree on something that works? Given the above misunderstanding, this question is no longer relevant. >Where is your IDE with error underlining and autocomplete list that comes up with each keystroke? A lot of Lisp hackers use Emacs with a few extensions. I am a Guile Scheme user, so I can only speak for my setup: Emacs, Paredit, and Geiser. Paredit provides efficient, and powerful structured editing support for s-expressions. Geiser provides REPL integration. Geiser can autocomplete symbols, jump to the definition points of variables, display documentation for a procedure or macro, show the values of variables under the cursor in the modeline, show function signatures in the modeline, and allow instant evaluation of arbitrary expressions with a simple keystroke (including jumping to the debugger when things go wrong), and probably some other things that I'm forgetting. It is the nicest development environment I have ever used. Common Lisp users also like Emacs and Paredit, but they typically use SLIME for REPL integration. > And finally s-expressions, which make you twist your mind in order to write and don't give clear structure of the code meaning to the reader, and not even considering macros... We'll have to disagree here. S-expressions are very nice, once you get used to them, which can be a bit difficult if your background is using C-like languages with infix notation. They remove complexity, make the language more regular (the operator is always the first element of a list, things that are operators in some languages like +, -, etc. are normal procedures that can be used as values), and allow for syntactic abstraction. Not only can you quote arbitrary expressions like '(+ 1 1) and manipulate symbols directly, the macro systems available in various Lisps allow for the creation of new syntax which is one of the most useful features a programming language could have. One of Paul Graham's essays talks about "top down, bottom up" design where the "bottom up" part involves defining new syntax when patterns emerge in your problem domain that you'd like to express in a more readable and less redundant way. Lisp allows you to build the language suitable for your problem. You seem to imply that macros are bad, but I think that languages that do not offer a macro system are fundamentally limited in the problems they are suited for solving. I by no means claim that s-expressions are a magic bullet, but I think you are biased in saying that they are inherently less readable than more complex syntaxes. There's a lot of mystique and misunderstanding around Lisp, and I hope I have cleared up a thing or two.
- tomp 11y ago
  > S-expressions [...] allow for syntactic abstraction I never bought this argument, based on my intuition, but now Julia has proved this argument to be invalid. Insisting only S-expressions allow macros is simply intelectually dishonest. Go check how Julia does metaprogramming; all the power of Lisp with none of the wierdness.
  - davexunit 11y ago
    You are claiming I made an assertion that I did not make. S-expressions allow for easy syntactic abstraction, as do other homoiconic syntaxes. I did not claim that it was the only possible thing that allows syntactic abstraction. I am aware of Julia's syntax, and I still much prefer the regularity of s-expressions. What you call weirdness, I call a feature.
  - lispm 11y ago
    Macros were available in S-Expression free languages long before Julia.
urs2102 11y ago
Well I think Lisp's biggest strength is also its biggest weakness: macros. By being able to bend a Lisp to your will, you trade your ability to standardize the language and build a community of libraries and tools around it. That being said, there's nothing like having a language which eventually becomes the best tool for solving the problem you're facing for at hand (as your Lisp will tend to evolve appropriately).
- lispm 11y ago
  People 'standardize' macros all the time. 1) Invent a new useful macro. 2) Package it as a library 3) Document it. 4) advertize it Since macros are written in a standard language and many cab be written in a portable way, it just another way of meta programming. Stuff like DEFCLASS, DEFMETHOD, ITERATE, WITH-GENSYMS, etc. started as portable libraries. What one has to learn: the language does not have a fixed amount of syntax. That's the price to pay: learning a new level of programming: linguistic meta programming.

lispm 11y ago

> Why are there so many dialects? That's a really funny question in a thread about another new programming language.

davexunit 11y ago

>When we look at Lisp we see archaic user interfaces, legacy keywords such as car, cdr and cons which bear no meaning to us mere mortals. Also no clear consensus on what extensions to use. Car, cdr, and cons take very little time to understand, but yes their meaning is steeped in history. "car" returns the first element of a pair, "cdr" (pronounced like "could-er") returns the second element of a pair, and "cons" creates pairs. Not that bad. However, today's Lisps put more emphasis on using pattern matchers than manually car/cdring down lists. >Why are there so many dialects? That's like asking "Why are there so many ALGOL derivatives?" Lisp classifies a family of languages, not a single language. It's like saying something has C-like syntax. >Can you not agree on something that works? Given the above misunderstanding, this question is no longer relevant. >Where is your IDE with error underlining and autocomplete list that comes up with each keystroke? A lot of Lisp hackers use Emacs with a few extensions. I am a Guile Scheme user, so I can only speak for my setup: Emacs, Paredit, and Geiser. Paredit provides efficient, and powerful structured editing support for s-expressions. Geiser provides REPL integration. Geiser can autocomplete symbols, jump to the definition points of variables, display documentation for a procedure or macro, show the values of variables under the cursor in the modeline, show function signatures in the modeline, and allow instant evaluation of arbitrary expressions with a simple keystroke (including jumping to the debugger when things go wrong), and probably some other things that I'm forgetting. It is the nicest development environment I have ever used. Common Lisp users also like Emacs and Paredit, but they typically use SLIME for REPL integration. > And finally s-expressions, which make you twist your mind in order to write and don't give clear structure of the code meaning to the reader, and not even considering macros... We'll have to disagree here. S-expressions are very nice, once you get used to them, which can be a bit difficult if your background is using C-like languages with infix notation. They remove complexity, make the language more regular (the operator is always the first element of a list, things that are operators in some languages like +, -, etc. are normal procedures that can be used as values), and allow for syntactic abstraction. Not only can you quote arbitrary expressions like '(+ 1 1) and manipulate symbols directly, the macro systems available in various Lisps allow for the creation of new syntax which is one of the most useful features a programming language could have. One of Paul Graham's essays talks about "top down, bottom up" design where the "bottom up" part involves defining new syntax when patterns emerge in your problem domain that you'd like to express in a more readable and less redundant way. Lisp allows you to build the language suitable for your problem. You seem to imply that macros are bad, but I think that languages that do not offer a macro system are fundamentally limited in the problems they are suited for solving. I by no means claim that s-expressions are a magic bullet, but I think you are biased in saying that they are inherently less readable than more complex syntaxes. There's a lot of mystique and misunderstanding around Lisp, and I hope I have cleared up a thing or two.

tomp 11y ago
> S-expressions [...] allow for syntactic abstraction I never bought this argument, based on my intuition, but now Julia has proved this argument to be invalid. Insisting only S-expressions allow macros is simply intelectually dishonest. Go check how Julia does metaprogramming; all the power of Lisp with none of the wierdness.
- davexunit 11y ago
  You are claiming I made an assertion that I did not make. S-expressions allow for easy syntactic abstraction, as do other homoiconic syntaxes. I did not claim that it was the only possible thing that allows syntactic abstraction. I am aware of Julia's syntax, and I still much prefer the regularity of s-expressions. What you call weirdness, I call a feature.
- lispm 11y ago
  Macros were available in S-Expression free languages long before Julia.

urs2102 11y ago

Well I think Lisp's biggest strength is also its biggest weakness: macros. By being able to bend a Lisp to your will, you trade your ability to standardize the language and build a community of libraries and tools around it. That being said, there's nothing like having a language which eventually becomes the best tool for solving the problem you're facing for at hand (as your Lisp will tend to evolve appropriately).

lispm 11y ago
People 'standardize' macros all the time. 1) Invent a new useful macro. 2) Package it as a library 3) Document it. 4) advertize it Since macros are written in a standard language and many cab be written in a portable way, it just another way of meta programming. Stuff like DEFCLASS, DEFMETHOD, ITERATE, WITH-GENSYMS, etc. started as portable libraries. What one has to learn: the language does not have a fixed amount of syntax. That's the price to pay: learning a new level of programming: linguistic meta programming.