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A road to Lisp: Why Lisp

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Re: A road to Lisp: Why Lisp

#11

The website seems to have a bug with syntax highlighting. Pieces of code included in the post text are black, you can still see the actual text if you select it with your mouse. Same bug on Chrome desktop and on Safari on iPad

I get this on both FF and Chrome.

Re: A road to Lisp: Why Lisp

#12
There are some truly powerful and unique things about Lisps, but I wish articles like this would stop including REPLs and hot-reloading. The former have been table stakes for interpreted languages (and some compiled ones!) for years, and the latter is neither unique nor particularly widely used (hot reloads have to tangle with state and patching, so resetting the world for ease of reasoning is considered a best practice for a reason).

Re: A road to Lisp: Why Lisp

#13
post #4

I must admit - I still don't understand macros. I get that they're code that's generated at compile time. But I don't understand how that's different than a function which evaluates other functions. I guess the latter would actually be evaluated at runtime? I think I get it conceptually but I'm not sure I have the muscle memory to reach for them. Anybody here have an "ah hah!" Moment with macros?

one way to see it is that it's a function that runs at compile time. for instance instead of dumping magic numbers/tables in a codebase you could put the code and substitute to their value at compile time.

but also it can change your code, so you get to do all the java annotation magic stuff.

Re: A road to Lisp: Why Lisp

#16

There are some truly powerful and unique things about Lisps, but I wish articles like this would stop including REPLs and hot-reloading. The former have been table stakes for interpreted languages (and some compiled ones!) for years, and the latter is neither unique nor particularly widely used (hot reloads have to tangle with state and patching, so resetting the world for ease of reasoning is considered a best pract…

Largely agreed.

I do think it is worth highlighting how many advanced parts of hot-reloading have already been covered in Common Lisp. Same with highlighting how the REPL is largely not used to directly type into, but is instead a very powerful interface for tools to interact with a running image.

But, again agreed that simply these existing are not that notable today.

Re: A road to Lisp: Why Lisp

#17
post #4

I must admit - I still don't understand macros. I get that they're code that's generated at compile time. But I don't understand how that's different than a function which evaluates other functions. I guess the latter would actually be evaluated at runtime? I think I get it conceptually but I'm not sure I have the muscle memory to reach for them. Anybody here have an "ah hah!" Moment with macros?

If you haven't read it, I'd suggest taking a look at Paul Graham's book On Lisp [0]. He says better, and with more examples than I'd provide in a comment block, what I'd write on the subject. Jump to chapter 8 for his discussion on the topic, referring back to chapter 7 if you find the macro definitions difficult to read.

[0] https://www.paulgraham.com/onlisptext.html

Re: A road to Lisp: Why Lisp

#18
post #4

I must admit - I still don't understand macros. I get that they're code that's generated at compile time. But I don't understand how that's different than a function which evaluates other functions. I guess the latter would actually be evaluated at runtime? I think I get it conceptually but I'm not sure I have the muscle memory to reach for them. Anybody here have an "ah hah!" Moment with macros?

If it helps, https://taeric.github.io/CodeAsData.html was my attempt at exploring "code as data" and what makes lisp different here. My specific focus was more to point out that "eval" in lisp doesn't just take in a string. But I think the same general points remain.

Re: A road to Lisp: Why Lisp

#19

There are some truly powerful and unique things about Lisps, but I wish articles like this would stop including REPLs and hot-reloading. The former have been table stakes for interpreted languages (and some compiled ones!) for years, and the latter is neither unique nor particularly widely used (hot reloads have to tangle with state and patching, so resetting the world for ease of reasoning is considered a best pract…

> The former have been table stakes for interpreted languages

I used to think so too back in the day when I was getting into Clojure. It was much later when I realized that when Lisp people talk about the REPL they’re usually talking not so much about the interactive CLI where you can evaluate commands easily but more so the ability to connect your program to a live session where you can quickly evaluate forms within your text editor and in the context of your running application, which enables much more interactive development than in other interpreted languages.

Re: A road to Lisp: Why Lisp

#20

There are some truly powerful and unique things about Lisps, but I wish articles like this would stop including REPLs and hot-reloading. The former have been table stakes for interpreted languages (and some compiled ones!) for years, and the latter is neither unique nor particularly widely used (hot reloads have to tangle with state and patching, so resetting the world for ease of reasoning is considered a best pract…

But with Clojure and immutable by default, hot reload is a real thing, it sounds like not just on JVM but even among lisps.
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