6 ms·

People should clarify what they mean by "Lisp". It's not a programming language or even a family of languages, it's a whole different computing system which jus

People should clarify what they mean by "Lisp". It's not a programming language or even a family of languages, it's a whole different computing system which just happens to have a programming language syntax on top. To get the most out of it and benefit from the powerful CL REPL, one needs to use Emacs (also written in Lisp). Some variants just drop that part and focus on the language only. Clojure and Racket are in that category. They lack the full power of CL; so they're just Lisp-syntax languages, not an actual Lisp. Maybe this high barrier to entry is why Lisp hasn't caught on even after 30 years of CL standardization. People often don't want to learn a new IDE to get the most out of Lisp. And if they stick to their current IDEs, they only get a glimpse of Lisp through its syntax (and much limited macro system). At that point, it's questionable whether whatever remains of Lisp does indeed provide any advantage over more mainstream languages (e.g., instead of learning Clojure, why not just learn a functional language like Elixir or Haskell? It's not like Clojure gives you the full Lisp power anyway.) Addendum: As one of the comments below mentioned (thank you @lispm), what I meant by "dropping the full power of Lisp" is the ability to modify a running program (continuation/restart system). Does Clojure REPL drop you in a new REPL in case of errors so you can literally change the running code or enter value for a missing variable?

tvink 2y ago
Why do you say that one needs to use Emacs? Like, I love using Emacs for the elisp and having the power of a full lisp machine, but for CL I didn't find sly-mode/slime to offer anything particular paradigm-shiftingly more powerful than the vim/nvim adaptions? This very side is written in CL in vi, if I'm not mistaken?
- kagevf 2y ago
  It's written in arc, a lisp language Paul Graham created. I think you're right about vi, though.
- bmitc 2y ago
  The site is written in Arc, which is a language written in an older version of Racket.
jay-barronville 2y ago
Clojure isn’t an “actual” Lisp because it’s not Common Lisp? Are you serious? Purity spiral much?
- tmtvl 2y ago
  Parent stated that some variations drop the 'whole different computing system' part of Lisp; which makes them Lisp-syntax languages rather than actual Lisps. I believe he means things like modifying a class and updating all existing instances without having to restart the application, the continuation/restart system, and so on. As an aside, please remember the guidelines: 'Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith.'
  - bmitc 2y ago
    The comment was well within the guidelines and is a viable point. When people make broad statements on Lisp like the original great-grandparent comment, they really need to clarify whether they're talking about Common Lisp or Lisp-likes. The original LISP doesn't have the features that Common Lisp has, so it'd be weird indeed to say that LISP wasn't an actual Lisp. In retrospect, the comment was talking about Common Lisp and not just Lisp-likes and tried to make the distinction but did a poor job of it with comments like: > Clojure and Racket are in that category. They lack the full power of CL; so they're just Lisp-syntax languages, not an actual Lisp.
    - lispm 2y ago
      Common Lisp and/or its implementations (and a bunch of other dialects) have most most of the features of the original LISP directly, often with minor changes, like many of its operators and data structures (like the linked list). It was designed to be largely backwards compatible with earlier LISP. Original LISP implementation features like the self hosting machine code compiler, loading of natively compiled code and the ability to save/restore images of the Lisp heap (which really was already in the 1960s LISP) are also provided by various later Lisp implementations, incl. several CL implementations.
dimitar 2y ago
Clojure also has a powerful REPL allowing you to interact with running processes in Emacs and in other editors and IDEa
amszmidt 2y ago
Alas there are two schools -- those that consider Lisp to be a language with its cradle defined by JMC's "Recursive Functions of Symbolic Expressions and Their Computation by Machine" and descendants thereof (Lisp1.5, MACLISP, Lisp Machine Lisp, Common Lisp, Emacs Lisp, ...). Sort of like with C, where Objective-C is clearly a "C", similar with C++. Then there is another school which considers the meta programability, REPL, syntax, ... the more philosophical notion of Lisp (Scheme, Clojure, Racket, Arc, ...). Some have no similarity with Lisp 1.5 descendants, and only share a superficial similarity. Lisp seems to be the only language where people really want to argue that they are a Lisp, nobody tries to argue that Javascript, Java, PHP etc are "a C" (similar syntax? semantics?). Does it even matter what is "a Lisp"? The barrier for Lisp (be it one school or the other) is about as high as Python, you type the name of the implementation and do stuff. CL specifically doesn't say anything interesting about the REPL (e.g., SBCL doesn't even allow by default to navigate forms on the command line), so to say that it is "powerful" is very misleading. Similar about the requirement of Emacs, you can use anything you like.
- samatman 2y ago
  > Lisp seems to be the only language where people really want to argue that they are a Lisp, nobody tries to argue that Javascript, Java, PHP etc are "a C" (similar syntax? semantics?). Does it even matter what is "a Lisp"? Lisp is far from being the only family of languages. There's the APL family, with k, j, q. There are the many Forths, to the point where it's been quipped that the language has more implementations than users. The C family rather clearly includes C++, Objective C, and D, as well as C itself (Swift and Rust are arguable here). I wouldn't put the three languages you named in the C family, but they're all Algols in a manner of speaking. At least, I routinely describe them that way, and people tend to understand what I mean. The reason no one argues that those languages are in the C family is just the broad and informal consensus that ABI compatibility is the most important feature, rather than syntax. Any time there's taxonomy going on, you'll have lumpers and splitters. I'm a lumper where Lisps are concerned. I would call Dylan and Julia Lisps, and have done so. If anything, what makes Lisp unique here is a faction of Common Lisp users who feel strongly that the only Lisp is Common, and historical variants which lead up to the Hyperspec (elisp being grandfathered in on that basis). I've never entirely understood this, but I don't let it bother me. That appears to be the source of the argument you reference in the section of your post I've quoted.
bmitc 2y ago
> Clojure and Racket are in that category. They lack the full power of CL; so they're just Lisp-syntax languages, not an actual Lisp. That's pretty debatable that Clojure and Racket lack the "full power of Common Lisp". For one, they're all three different languages, each one having something the other doesn't. And another is that Racket is not a Lisp and doesn't purport to be. It's very much in the Scheme camp, but even then it is clearly it's own thing.
bitwize 2y ago
You don't need to use Emacs to write Lisp, just like you don't need to use the ISPF dataset editor to write COBOL. That said, unlike COBOL, most of whose programmers these days use Visual Studio Code or a modern IDE, Emacs is still the best readily available support one can get for Lisp programming -- and that's kind of a black mark against Lisp. I really wish Allegro or somebody would deliver a modern IDE for an affordable price, or at least good VSCode plugin support.
- massysett 2y ago
  Some folks prefer the LispWorks IDE.
  - bitwize 2y ago
    LispWorks is great but the Personal Edition isn't good for much beyond classroom exercises and even some of the hobbyist versions can run you four figs. Not exactly enticing for those looking to get started.
iLemming 2y ago
Oh, come on. Next, you're going to claim that Clojure is not "an actual Lisp" because it contains neither "Common" nor "Lisp" in the name? Clojure is a proper Lisp. Period. It's homoiconic, it has macros, it is a Lisp-1 Lisp, not "kind of a Lisp-1 thing" or "a thing with a Lispy syntax." It is a proper, legit, respectable addition to the family of Lisps. Yes, it's not a Common Lisp, but it's a Lisp nevertheless. A three-wheeled car is still considered a car. While it may fall into a specific category of vehicles and sometimes be classified as a motorcycle or under a special designation depending on the jurisdiction, it is generally recognized as a type of car. > why not just learn a functional language like Elixir or Haskell Have you ever considered that specifically because Clojure borrowed some ideas from Lisp, some from object-oriented languages, and some from FP, it makes it a really good choice for certain applications and developers? Besides, is it really a big deal not to have proper continuation/restart in Clojure? It really depends. For many use cases, the error handling techniques in Clojure are adequate and align well with its functional paradigms. I've been using Clojure for several years and haven't heard anyone seriously complaining about the lack of continuations, despite many former Common Lispers now being full-time Clojuristas. There are also some philosophical differences: The philosophy behind Clojure focuses on simplicity and building software with different tools and techniques, which can achieve similar robustness in practice. So, I don't know. Sure, I personally wouldn't mind having built-in support for continuations in Clojure, and there were some attempts to bring that via libraries, but this was never a "high priority thing" for Clojurists. If in 17 years of existence of Clojure (and almost 40 years of Emacs Lisp), that never became a thing everyone wants, I guess it's not as critical as you paint it to be.
- vzcx 2y ago
  Lisp is a family of languages. They share a common ancestry. That family is larger than Common Lisp, although Common Lisp is might be the last living descendant. While there are common traits among members of the family (parenthesized notation, certain special forms, symbol names), the presence of these traits does not itself define the family any more than having fins implies that an animal must be a member of the fish family. A language is not only its syntax, but also it's semantics. Lisp is not just parentheses or even 'homoiconicity.' In addition to the surface syntax, there is a shared cultural understanding of what certain symbols mean, how they fit together into a system, what a symbol even is, and so on. Given that, while there is some surface resemblance to lisp, it's plainly obvious to me that Clojure does not belong in that family. This is not a dig at Clojure! Clojure makes a lot of people happy and productive, and that's great. It's my third favorite language on the JVM. But when you take a closer look at some very core design decisions made in Clojure you'll find that they depart strongly enough from all the other languages in the Lisp family that it belongs to a distinct language family. A few of them: - Reader doesn't intern symbols - EQUAL symbols aren't EQ - Introduction of vars - Cons doesn't cons - No numeric tower - Backquote behavior These things don't necessarily come up in day-to-day programming, so it might seem like quibbling, but these are fairly central differences in meaning. I think it's sensible to consider "Clojures" as a distinct language family. Rhere are languages like Fennel and Hy that are clearly Clojures, and I'm sure there will be more.

tvink 2y ago

Why do you say that one needs to use Emacs? Like, I love using Emacs for the elisp and having the power of a full lisp machine, but for CL I didn't find sly-mode/slime to offer anything particular paradigm-shiftingly more powerful than the vim/nvim adaptions? This very side is written in CL in vi, if I'm not mistaken?

kagevf 2y ago
It's written in arc, a lisp language Paul Graham created. I think you're right about vi, though.
bmitc 2y ago
The site is written in Arc, which is a language written in an older version of Racket.

jay-barronville 2y ago

Clojure isn’t an “actual” Lisp because it’s not Common Lisp? Are you serious? Purity spiral much?

tmtvl 2y ago
Parent stated that some variations drop the 'whole different computing system' part of Lisp; which makes them Lisp-syntax languages rather than actual Lisps. I believe he means things like modifying a class and updating all existing instances without having to restart the application, the continuation/restart system, and so on. As an aside, please remember the guidelines: 'Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith.'
- bmitc 2y ago
  The comment was well within the guidelines and is a viable point. When people make broad statements on Lisp like the original great-grandparent comment, they really need to clarify whether they're talking about Common Lisp or Lisp-likes. The original LISP doesn't have the features that Common Lisp has, so it'd be weird indeed to say that LISP wasn't an actual Lisp. In retrospect, the comment was talking about Common Lisp and not just Lisp-likes and tried to make the distinction but did a poor job of it with comments like: > Clojure and Racket are in that category. They lack the full power of CL; so they're just Lisp-syntax languages, not an actual Lisp.
  - lispm 2y ago
    Common Lisp and/or its implementations (and a bunch of other dialects) have most most of the features of the original LISP directly, often with minor changes, like many of its operators and data structures (like the linked list). It was designed to be largely backwards compatible with earlier LISP. Original LISP implementation features like the self hosting machine code compiler, loading of natively compiled code and the ability to save/restore images of the Lisp heap (which really was already in the 1960s LISP) are also provided by various later Lisp implementations, incl. several CL implementations.

dimitar 2y ago

Clojure also has a powerful REPL allowing you to interact with running processes in Emacs and in other editors and IDEa

amszmidt 2y ago

Alas there are two schools -- those that consider Lisp to be a language with its cradle defined by JMC's "Recursive Functions of Symbolic Expressions and Their Computation by Machine" and descendants thereof (Lisp1.5, MACLISP, Lisp Machine Lisp, Common Lisp, Emacs Lisp, ...). Sort of like with C, where Objective-C is clearly a "C", similar with C++. Then there is another school which considers the meta programability, REPL, syntax, ... the more philosophical notion of Lisp (Scheme, Clojure, Racket, Arc, ...). Some have no similarity with Lisp 1.5 descendants, and only share a superficial similarity. Lisp seems to be the only language where people really want to argue that they are a Lisp, nobody tries to argue that Javascript, Java, PHP etc are "a C" (similar syntax? semantics?). Does it even matter what is "a Lisp"? The barrier for Lisp (be it one school or the other) is about as high as Python, you type the name of the implementation and do stuff. CL specifically doesn't say anything interesting about the REPL (e.g., SBCL doesn't even allow by default to navigate forms on the command line), so to say that it is "powerful" is very misleading. Similar about the requirement of Emacs, you can use anything you like.

samatman 2y ago
> Lisp seems to be the only language where people really want to argue that they are a Lisp, nobody tries to argue that Javascript, Java, PHP etc are "a C" (similar syntax? semantics?). Does it even matter what is "a Lisp"? Lisp is far from being the only family of languages. There's the APL family, with k, j, q. There are the many Forths, to the point where it's been quipped that the language has more implementations than users. The C family rather clearly includes C++, Objective C, and D, as well as C itself (Swift and Rust are arguable here). I wouldn't put the three languages you named in the C family, but they're all Algols in a manner of speaking. At least, I routinely describe them that way, and people tend to understand what I mean. The reason no one argues that those languages are in the C family is just the broad and informal consensus that ABI compatibility is the most important feature, rather than syntax. Any time there's taxonomy going on, you'll have lumpers and splitters. I'm a lumper where Lisps are concerned. I would call Dylan and Julia Lisps, and have done so. If anything, what makes Lisp unique here is a faction of Common Lisp users who feel strongly that the only Lisp is Common, and historical variants which lead up to the Hyperspec (elisp being grandfathered in on that basis). I've never entirely understood this, but I don't let it bother me. That appears to be the source of the argument you reference in the section of your post I've quoted.

bmitc 2y ago

> Clojure and Racket are in that category. They lack the full power of CL; so they're just Lisp-syntax languages, not an actual Lisp. That's pretty debatable that Clojure and Racket lack the "full power of Common Lisp". For one, they're all three different languages, each one having something the other doesn't. And another is that Racket is not a Lisp and doesn't purport to be. It's very much in the Scheme camp, but even then it is clearly it's own thing.

bitwize 2y ago

You don't need to use Emacs to write Lisp, just like you don't need to use the ISPF dataset editor to write COBOL. That said, unlike COBOL, most of whose programmers these days use Visual Studio Code or a modern IDE, Emacs is still the best readily available support one can get for Lisp programming -- and that's kind of a black mark against Lisp. I really wish Allegro or somebody would deliver a modern IDE for an affordable price, or at least good VSCode plugin support.

massysett 2y ago
Some folks prefer the LispWorks IDE.
- bitwize 2y ago
  LispWorks is great but the Personal Edition isn't good for much beyond classroom exercises and even some of the hobbyist versions can run you four figs. Not exactly enticing for those looking to get started.

iLemming 2y ago

Oh, come on. Next, you're going to claim that Clojure is not "an actual Lisp" because it contains neither "Common" nor "Lisp" in the name? Clojure is a proper Lisp. Period. It's homoiconic, it has macros, it is a Lisp-1 Lisp, not "kind of a Lisp-1 thing" or "a thing with a Lispy syntax." It is a proper, legit, respectable addition to the family of Lisps. Yes, it's not a Common Lisp, but it's a Lisp nevertheless. A three-wheeled car is still considered a car. While it may fall into a specific category of vehicles and sometimes be classified as a motorcycle or under a special designation depending on the jurisdiction, it is generally recognized as a type of car. > why not just learn a functional language like Elixir or Haskell Have you ever considered that specifically because Clojure borrowed some ideas from Lisp, some from object-oriented languages, and some from FP, it makes it a really good choice for certain applications and developers? Besides, is it really a big deal not to have proper continuation/restart in Clojure? It really depends. For many use cases, the error handling techniques in Clojure are adequate and align well with its functional paradigms. I've been using Clojure for several years and haven't heard anyone seriously complaining about the lack of continuations, despite many former Common Lispers now being full-time Clojuristas. There are also some philosophical differences: The philosophy behind Clojure focuses on simplicity and building software with different tools and techniques, which can achieve similar robustness in practice. So, I don't know. Sure, I personally wouldn't mind having built-in support for continuations in Clojure, and there were some attempts to bring that via libraries, but this was never a "high priority thing" for Clojurists. If in 17 years of existence of Clojure (and almost 40 years of Emacs Lisp), that never became a thing everyone wants, I guess it's not as critical as you paint it to be.

vzcx 2y ago
Lisp is a family of languages. They share a common ancestry. That family is larger than Common Lisp, although Common Lisp is might be the last living descendant. While there are common traits among members of the family (parenthesized notation, certain special forms, symbol names), the presence of these traits does not itself define the family any more than having fins implies that an animal must be a member of the fish family. A language is not only its syntax, but also it's semantics. Lisp is not just parentheses or even 'homoiconicity.' In addition to the surface syntax, there is a shared cultural understanding of what certain symbols mean, how they fit together into a system, what a symbol even is, and so on. Given that, while there is some surface resemblance to lisp, it's plainly obvious to me that Clojure does not belong in that family. This is not a dig at Clojure! Clojure makes a lot of people happy and productive, and that's great. It's my third favorite language on the JVM. But when you take a closer look at some very core design decisions made in Clojure you'll find that they depart strongly enough from all the other languages in the Lisp family that it belongs to a distinct language family. A few of them: - Reader doesn't intern symbols - EQUAL symbols aren't EQ - Introduction of vars - Cons doesn't cons - No numeric tower - Backquote behavior These things don't necessarily come up in day-to-day programming, so it might seem like quibbling, but these are fairly central differences in meaning. I think it's sensible to consider "Clojures" as a distinct language family. Rhere are languages like Fennel and Hy that are clearly Clojures, and I'm sure there will be more.