Yeah, I agree. Lisp is best with small functional blocks.
"It used to be thought that you could judge someone's character by looking at the shape of his head. Whether or not this is true of people, it is generally true of Lisp programs. Functional programs have a different shape from imperative ones. The structure in a functional program comes entirely from the composition of arguments within expressions, and since arguments are indented, functional code will show more variation in indentation. Functional code looks fluid on the page; imperative code looks solid and blockish, like Basic." -- On Lisp (http://www.paulgraham.com/onlisptext.html; page 30)
As function size grows, it doesn't look quite so pretty. An example from news.arc:
(if no.user
(submit-login-warning url title showtext text)
(~and (or blank.url valid-url.url)
~blank.title)
(submit-page user url title showtext text retry*)
(len> title title-limit*)
(submit-page user url title showtext text toolong*)
(and blank.url blank.text)
(let dummy 34
(submit-page user url title showtext text bothblank*))
(let site sitename.url
(or big-spamsites*.site recent-spam.site))
(msgpage user spammage*)
(oversubmitting user ip 'story url)
(msgpage user toofast*)
(let s (create-story url process-title.title text user ip)
(story-ban-test user s ip url)
(when ignored.user (kill s 'ignored))
(submit-item user s)
(maybe-ban-ip s)
"newest"))
There's a multi-branch if here, with lots of else ifs. But it's hard to see. In my toy dialect[1], I've added[2] colons as syntactic sugar that expands to nothing:
(if no.user
: (submit-login-warning url title showtext text)
(~and (or blank.url valid-url.url)
~blank.title)
: (submit-page user url title showtext text retry*)
(len> title title-limit*)
: (submit-page user url title showtext text toolong*)
(and blank.url blank.text)
: (let dummy 34
(submit-page user url title showtext text bothblank*))
(let site sitename.url
(or big-spamsites*.site recent-spam.site))
: (msgpage user spammage*)
(oversubmitting user ip 'story url)
: (msgpage user toofast*)
: (let s (create-story url process-title.title text user ip)
(story-ban-test user s ip url)
(when ignored.user (kill s 'ignored))
(submit-item user s)
(maybe-ban-ip s)
"newest"))
(cond
[no.user
(submit-login-warning url title showtext text)]
[(~and (or blank.url valid-url.url)
~blank.title)
(submit-page user url title showtext text retry*)]
[(len> title title-limit*)
(submit-page user url title showtext text toolong*)]
[(and blank.url blank.text)
(let dummy 34
(submit-page user url title showtext text bothblank*))]
[(let site sitename.url
(or big-spamsites*.site recent-spam.site))
(msgpage user spammage*)]
[(oversubmitting user ip 'story url)
(msgpage user toofast*)]
[t
(let s (create-story url process-title.title text user ip)
(story-ban-test user s ip url)
(when ignored.user (kill s 'ignored))
(submit-item user s)
(maybe-ban-ip s)
"newest")])
Doesn't seem like an improvement. The big aha moment for me was to notice that in imperative languages (C, Java, python, ruby) you got the distinguishing separator between the check and the action:
if (test expr goes here) { action goes here; }
else if (next text expr) { ...; }
The intervening keywords also help, but the parens vs curlies are a huge visual signal.
Comments
Yeah, I agree. Lisp is best with small functional blocks.
"It used to be thought that you could judge someone's character by looking at the shape of his head. Whether or not this is true of people, it is generally true of Lisp programs. Functional programs have a different shape from imperative ones. The structure in a functional program comes entirely from the composition of arguments within expressions, and since arguments are indented, functional code will show more variation in indentation. Functional code looks fluid on the page; imperative code looks solid and blockish, like Basic." -- On Lisp (http://www.paulgraham.com/onlisptext.html; page 30)
As function size grows, it doesn't look quite so pretty. An example from news.arc:
There's a multi-branch if here, with lots of else ifs. But it's hard to see. In my toy dialect[1], I've added[2] colons as syntactic sugar that expands to nothing: [1] https://github.com/akkartik/wart#readme[2] http://arclanguage.org/item?id=16495
Racket (and maybe other Schemes) lets you interchange [] and () freely. Helps a bit. e.g.
Yeah I considered this:
Doesn't seem like an improvement. The big aha moment for me was to notice that in imperative languages (C, Java, python, ruby) you got the distinguishing separator between the check and the action: The intervening keywords also help, but the parens vs curlies are a huge visual signal.