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0 points0823498723498722y ago0 comments

in that case, pretend I wrote "grammarless"

(in the examples above —which missed the prologs— I'm pretty sure the parsing is trivial on the order of "you can see everything that handles 'parsing' without needing to scroll a window", and in several of those examples it'd still be true even if your windows were only 25 lines long)

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whartung2y ago· 2 in thread

  > in that case, pretend I wrote "grammarless"

Gonna call you out on that as well. Forth, sure. Forth is...Forth.

But Lisp is not grammarless. Smalltalk is not either. The Lisp reader, notably Common Lisp, is a non-trivial piece of code. The Common Lisp lambda list, as a language construct, is not trivial either. (Dare I mention the CL LOOP macro?) Just because everything is "a list, symbol, or constant" does necessarily make the parsing problem trivial.

It SEEMS simple, but then you get into it, and you find you fall into the weeds.

rewmie2y ago

It seems those in this discussion arguing that they don't need a parser or a grammar simply aren't aware they're implementing ad-hoc parsers and grammars but doing it poorly.

082349872349872OP2y ago

Not only am I exactly aware of that, I am even advocating it.

OP wants to write a hobby language, not reimplement Common Lisp.

If OP wants sexprs, they can get quick-and-dirty sexprs by:

  (1) substituting spaces around each paren in the input
  (2) breaking input up into a list of whitespace separated words
  (3) folding over the resulting list (by looking at its parens) into a tree

Sure, that's done poorly. However, it takes under 15 minutes (and under 15 lines?) to get them past their sticking point, and if the rest of their language (especially the part that differs from all other languages) actually turns out to be worth pursuing, they can always implement (or import) a real —or at least a better— reader later.

See https://news.ycombinator.com/item?id=36593060

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rewmie2y ago

> in that case, pretend I wrote "grammarless"

You are always parsing a grammar. It seems you simply aren't aware of it.

Every single time you write code that expects to find a certain type of token after another type of token, you have a grammar.

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