Comment by troad
14 days ago
Certainly, but the original quote was "It is quite hard to even tell a noun from a verb" (emph. added), and this is correct, you can't tell whether an identifier refers to a function or variable in Scheme by sight alone. This seems desirable if one wants first-class functions, and is very much an intentional choice for Scheme, but it can admittedly be more difficult to build up a mental model of new code if you have no idea what's a variable and what's a function (esp. amidst an already-difficult-to-grok sea of parentheses).
Notably, this isn't intrinsic to Lisps - Common Lisp uses a different syntax and namespace for function names and variables. My understanding is that Scheme et al's decision to merge the namespaces/syntax was not without controversy in the Lisp community (the Lisp-1 v Lisp-2 debate).[0]
[0] http://www.nhplace.com/kent/Papers/Technical-Issues.html
The only "verb" is the open paren. Other languages just make this simple and fundamental rule way more complicated.
> you can't tell whether an identifier refers to a function or variable in Scheme by sight alone
Nor in C. Nor in JavaScript. Nor in Java. Nor in...
I mean, what is "foo"? Could be the name of a function. Could be a char variable. Could be a double precision float. Could be a pointer to an array of pointers to functions returning doubles. Without going back to its definition (or prototype, for function arguments) you can't tell, much the same as you can't tell in Scheme without looking for the matching define or set!
I feel like I must be missing something here. What?
> I feel like I must be missing something here. What?
If I were to hazard a guess at what the original poster was getting at, it might be the culture of those languages, combined with the power of Lisp to redefine its own syntax.
Lispers value concision, love higher-order functions, and love wrapping things in other things to reuse code, so you might easily see a non-trivial stretch of code without a single function call you recognise. Imagine code where the smallest chunk look something like (dq red foo '(hat n (ddl m) f)). There could be anywhere between zero and eight functions in that snippet, or any one of those might be a macro which re-orders the others in any way (or perhaps its parents include a macro, in which case you really can't assume anything about how / if this stretch is executed at all), it could be a wrapper around something that in other languages would need to be an operator (perhaps it's an if statement?), etc etc.
It's absolutely true you can shoot yourself in the foot in any language, but Lisp is unusually good for it. It's part of its power, but that power comes with a cost. Imagine talking with someone that had a proclivity for making up words. In small doses, this might be fun and save time. In larger doses, you begin losing the thread of the conversation. Lisp is sorta like that. It might seem flammorous, but before you prac it grombles, and you plink trooble blamador!
> Imagine talking with someone that had a proclivity for making up words.
All software is written by making up new words. The bigger the software, the more words.
> you can shoot yourself in the foot in any language, but Lisp is unusually good for it
I've never shot myself in the foot writing Lisp, and have not heard any anecdotes about it. (Well, maybe the one about Cycorp's Cyc decades old code base being large and inscrutable.)
You're making shit up.
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