Comment by silentbicycle | Hacker News Reader

Comment by silentbicycle | Hacker News Reader

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It takes a lot of chutzpah for Larry Wall to say anything critical about Lisp syntax. Larry Wall. Come on.

I'm not the author of the comment above, but I think Erlang's syntax is effective in that it strongly emphasizes computation by pattern matching. If you write very imperative code in it (as people tend to, coming from Ruby or what have you), yes, it will look gnarly. Good Erlang code looks qualitatively different. There are pretty good examples of hairy, imperative Erlang code being untangled in this blog post: http://gar1t.com/blog/2012/06/10/solving-embarrassingly-obvi...

The . , ; thing is a bit of a hack, admittedly -- I suspect that comes from using Prolog's read function to do parsing for the original versions of Erlang (which was a Prolog DSL), and reading every clause of a function definition at the same time. Prolog ends every top-level clause with a period, not "; ; ; ; .". (Not sure, but a strong hunch, supported by Erlang's history.) I got used to it pretty quickly, though.

As in Prolog ',' and ';' are separators: ',' behaves like an and, first do then and then do this (as in Prolog); while ';' is an or, do this clause or do this clause (again as in Prolog). '.' ends something, in this case a function definition. Erlang's functions clauses are not the same as Prolog's clauses which explains the difference.

It is very simple really, think of sentences in English and it all becomes trivially simple.How many sentences end in a ';'?. And you almost never need to explicitly specify blocks.

Here http://ferd.ca/on-erlang-s-syntax.html are some alternate ways of looking at it.

Indeed. It makes sense to me. Are my intuitions about the origins of ;s separating top-level clauses accurate?

(Hello, Robert! :) )

Sort of. The syntax evolved at the same time we were moving from Prolog onto our own implementation, which forced us to write our own parser and not rely on the original Prolog one. The biggest syntax change came around 1991, since then it has been mainly smaller additions and adjustments.

To be fair, that was Larry Wall reacting to criticism in 1994 https://groups.google.com/forum/?fromgroups#!msg/comp.lang.l...

Anyways, my experience is that all languages will get people criticizing them. And, in my experience, those kinds of criticisms should almost always be categorized as "does not want to talk about language FOO" and a proper response is probably something like "if you don't want to give that subject the respect it deserves, let's change the subject to something you find interesting".

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