First off, I apologize if I did not add a disclaimer saying I could be wrong. But given this, what is exactly the difference between denotaional and operational semantics? I base what I said on [my understanding of books about language theory. But it seems like I got the wrong gist. Where do you recommend I start?
I know about all this — I actually began implementing my own JVM language a few days ago. I know Android uses Dalvik btw. But I guess a lot of people can use this info; infodump is always good. I do that.
btw I actually have messed around with libgcc-jit and I think at least on x86, it makes zero difference. I once did a test:
– Find /e/ with MAWK -> 0.9s
– Find /e/ with JAWK -> 50s.
No shit! It’s seriously slow.
Now compare this with go-awk: 19s.
Go has reference counting and heap etc, basically a ‘compiled VM’. I think if you want fast code, ditch runtime.
Hey now, I am just a yokel from Mazar-Sharif, New York who sells dingbat carcasses for infant consumption, but does Android even use JVM? I was under the consumption it uses Dalvik? Let me consume a dingbat – ok, so who cares what “java” gets compiled to, JIT, AOT even tree-walked, we’re talking about JVM here. Here: https://sourceforge.net/projects/jasmin/ An ancient JVM bytecode assembler.
I actually started work on a tool similar to Forth’s VMGEN. It will generate Stack VM’s in several languages leveraging m4, just like Bison. The difference between it, and VMGEN would be that it actually adds GC and threading. Based on Xiao-Feng Li’s book.
True, but see, all these build up on the theoretical regex. The theoretical regex indeed has only 3 operators: dot for concatenation, pipe for alteration and the ‘kleene star’ [re: Sipser’s]. These 3 operators can express a finite state automata. You don’t really need all that other operators. Read this: https://swtch.com/~rsc/regexp/regexp1.html Algorithms like Thompson construction can translate a regex to a non-deterministic automata quite quickly, and then from there you can make a DFA or just simulate the NFA.
I would not call PCRE ‘regular expression’ really. If you read the article I gave you it explains why they are mostly a practical utility than a theoretical groundwork. The regex in use today is far from the regex one learns about in books.
I think regex is abused. People use it to parse context-free grammars. Extremely intricate and feature-rich patterns cause people to make mistakes, and end up with security holes!
That being said, I really enjoy NeoVim’s regex. I also like Perl’s. But I would not rely on them for parsing, or even lexing.
What should we talk about then, glob patterns (which are NOT regular expressions, for the love of all that is holy and unholy, stop calling glob patterns RE!)
You guys do realize that, Rust, a compiled, statically-typed systems language is not a good suit for scripting right? I understand, when I was a beginner years ago I used Rust for scripting. That was because I was clueless. Right now I am using Rust for what it’s suited for, systems programs. This is a scripting task. I really ask you to learn about the difference between scripting and programming.
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Can’t load this website, what is it?