Destroy All Software relaunches | Hacker News Reader

Destroy All Software relaunches

destroyallsoftware.com

70 pointspg_bot18 comments

I watched the introduction video and the author made a surprising claim: that deciding if a string of characters is valid Python code is fundamentally simpler than deciding if it's valid code in some other language.

In more precise terms, the assertion is that Python's grammar belongs to the context-free class of languages in Chomsky's hierarchy.

Here's an interesting discussion about that and the more philosophical question "what is valid code?" on comp.theory: https://groups.google.com/forum/m/#!msg/comp.theory/nJzOyRnA...

I don't really have time to watch a video at the moment, but I'm not really sure what the significance is. If you allow look-ahead, I would think that most popular languages can be parsed with an LALR(2) parser (e.g. yacc/bison). I've even implemented the SIP protocol with an LALR(K) (antlr) parser and SIP is insane :-). I often wonder about Ruby, especially with the leading period that's allowed. But there are a lot languages with really simple grammars out there. I can't imagine that python is anywhere near the top of the list. In practical terms, simple grammars make it easy to write tools. I suppose you can also save stack space if you have simple grammars, which may be significant in some situations. Other than that, I'm not sure why it matters. Can you elaborate a bit more?

I don't think there's any great significance behind it.

I guess I jumped at the idea because it seemed to provide a simple theoretical explanation as to why Python is easier to grok than other languages which don't have context-free grammars.

Yep, that was my motivation: to hint at deeper connections to programming at large, rather than focusing on technical concerns that are confined to parser implementation and therefore esoteric to an outsider.

Python's grammar is context-sensitive until the lexer processes indentation. There are other programming languages whose grammar is context-free.

I went back and forth on that statement for exactly this reason, but kept it because the whitespace is handled in the lexer, as you mentioned. The Python grammar itself is context-free, and the grammar is the only part that I expect the series to examine.

You imply that indentation isn't a part of Python's grammar...

It's not part of the Python grammar as specified in the file called Grammar in the canonical implementation of the language (https://github.com/python/cpython/blob/master/Grammar/Gramma...). Of course it's part of the grammar in the larger sense. I don't think that that distinction is important when trying to convince someone with no theoretical background to learn these topics, which is what the video in question is trying to do.

Love the site, but $348 a year feels really steep. Glad I purchased most of the library before the pricing model change.

It's pretty steep, and I'm not sure I'll be keeping the subscription going in a few months time.

Yeah, yeah, "professional development is priceless", "it's less than the cost of a $whatever", herp derp, etc...

But we're staring down an imminent recession and a plummeting Sterling value right now, so every little saving helps, even for well-paid developers and their families.

Agreed which is why I will likely not subscribe. If people are willing to pay that price point then that's fine. $15 per episode for a variable schedule seemed pricey, if you dont care about the immediacy of it it basically turns into $29 once a year where you download the back-catalog and watch at your leisure. In that sense you are paying for the ability to get it as it comes out, not for the content itself.

I think thats why he charges per month. Its pretty easy to go through an entire seasons worth of videos in under a month. I found $29 for a seasons worth of videos to be worth it. He used to charge per season with no subscription, and before that it was subscription based.

I'm more curious about how frequently he's going to be releasing videos. If its less than 2-3 a week, I'd probably just opt to wait until the season is over.

> If its less than 2-3 a week, I'd probably just opt to wait until the season is over.

Apparently it's going to be twice per month

This is basically an ad. Is this worth discussing?

I was actually hoping this was about destroying the concept of software/product "relaunches".

Yeah, that's how I read it, too. Given that there is no actual article, the headline should be changed to "Relaunch of Destroy All Software" (which I think I would have ignored).

I agree on both counts; but the latter only because I wasn't aware of “Destroy All Software” beforehand. Perhaps “Relaunch of "Destroy All Software" video series"? It conveys more information, while being reasonably likely that I would click it.

Given that it was upvoted I'd say yes.

Also the original DAS where some of the finest programming videos around at the time and it's relevant to this community.

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