5 ms·

Compilers Targetting Parrot

32 points by draegtun 16y ago

RiderOfGiraffes 16y ago
This returns me to the question I asked here: http://news.ycombinator.com/item?id=1361382 http://news.ycombinator.com/item?id=1361382 If I'm compiling, what should I target? I could target LLVM, C, some high-level compilable langauge, or now, Parrot. There doesn't seem to be any cogent, clear, knowledgable discussion of the various features and merits. I suppose asking for one is like asking "which language is best," and the answer will always be "it depends."
- stefano 16y ago
  I've used Parrot as a target for a language implementation. It supports a lot of stuff out of the box (even multimethods!) and it's quite easy to get started. It also provides tools to help you build a compiler, like a parser generator integrated with the rest of the system. The problem is that right now it is quite slow, slower than Perl or Python, and a bit buggy. It would be an ideal target platform for dynamic languages otherwise. I wouldn't use it for something needed in production at the moment.
  - WalterGR 16y ago
    > a bit buggy Anything off the top of your head that you've been bit by?
    - stefano 16y ago
      Threading just doesn't work (it's going to be rewritten from scratch). Sometimes there are segfaults within managed code and sometimes there are memory leaks. Sometimes an assertion in the VM fails, causing the program to halt with a stack trace. A few releases ago the compiler of Parrot's assembly language reported wrong line numbers in error messages, but this has been fixed.
      - WalterGR 16y ago
        All those "sometimes" seems to suggest that Parrot is much more than a bit buggy. A memory leak is one thing, but segfaults and assertion failures... Down to brass tacks: is this thing usable in its current state?
        stefano 16y ago
        > Down to brass tacks: is this thing usable in its current state? Experimentation and quick and dirty prototypes? Yes. Production code? No.
- wingo 16y ago
  Whatever seems like the most fun to you, of course. Also: there are many more possible compilation targets than ones you list.
  - RiderOfGiraffes 16y ago
    Yes, exactly, and that's why I was asking for recommendations and suggestions. I have been largely unable to find anything that gives a sensible overview of the technology and the various trade-offs. Hence my question, although it seems like this is the wrong audience/forum.
    - wingo 16y ago
      There is no technical answer. OK, there are terrible answers, but not everyone agrees about which those are. In the end making a compiler is a world-affecting act: both to your own, and to those of others. You have to decide socially which group you want to associate yourself with, what kind of world you want.
- JoachimSchipper 16y ago
  For the more static languages, LLVM seems hot and well-supported right now. There is a rich tradition of compiling via C, with good and bad results. Gambit Scheme compiles via C and is one of the fastest Scheme systems around, with good interoperability via C. The Glassgow Haskell Compiler can also compile via C, but that's, AFAIK, an unmaintainable mess (search for "evil mangler").
avar 16y ago
Parrot's been claiming that it's slow and incomplete now, but a solution to that is just around the corner for a few years. Maybe that's true, but I think that'd be the main concern of any compiler writer thinking of targeting it. It's not a mature platform with known pros and cons, unlike the JVM or LLVM. I hope it all turns out for the best and Parrot delivers on its promises. But I can see why e.g. the PHP team isn't rushing to target it given the state of its native languages.
- j_baker 16y ago
  These things take a long time. Heck, it might even be a bit early to call LLVM mature. Sure, it supports a C and C++ compiler, but I don't think it has anything production-ready for much else.
  - avar 16y ago
    It's in extensive use by Apple on the iPhone and in XCode, and outside Apple. The JVM is also well understood and widely deployed. By comparison the Parrot project with the widest use is Rakudo, which is still just at a testing stage. Maybe there's some larger user of Parrot that I haven't heard about, so correct me if I'm wrong.
    - amalter 16y ago
      fyi - with the JDK7 - the JVM can also target the LLVM (for JIT'ing) through Project Zero (http://openjdk.java.net/projects/zero/ http://openjdk.java.net/projects/zero/) One Bytecode to rule them all, One Bytecode to find them, One Bytecodeto bring them all and in the darkness bind them :-)
    - chromatic 16y ago
      Lua 5.2 has been feature complete on Parrot for years. Like LLVM and the JVM, we'll keep tuning and improving and fixing bugs and adding features to make language implementation easier, but the correlation between "maturity" and "use" is strong.

32 points by draegtun 16y ago

This returns me to the question I asked here: http://news.ycombinator.com/item?id=1361382 http://news.ycombinator.com/item?id=1361382 If I'm compiling, what should I target? I could target LLVM, C, some high-level compilable langauge, or now, Parrot. There doesn't seem to be any cogent, clear, knowledgable discussion of the various features and merits. I suppose asking for one is like asking "which language is best," and the answer will always be "it depends."

stefano 16y ago
I've used Parrot as a target for a language implementation. It supports a lot of stuff out of the box (even multimethods!) and it's quite easy to get started. It also provides tools to help you build a compiler, like a parser generator integrated with the rest of the system. The problem is that right now it is quite slow, slower than Perl or Python, and a bit buggy. It would be an ideal target platform for dynamic languages otherwise. I wouldn't use it for something needed in production at the moment.
- WalterGR 16y ago
  > a bit buggy Anything off the top of your head that you've been bit by?
  - stefano 16y ago
    Threading just doesn't work (it's going to be rewritten from scratch). Sometimes there are segfaults within managed code and sometimes there are memory leaks. Sometimes an assertion in the VM fails, causing the program to halt with a stack trace. A few releases ago the compiler of Parrot's assembly language reported wrong line numbers in error messages, but this has been fixed.
    - WalterGR 16y ago
      All those "sometimes" seems to suggest that Parrot is much more than a bit buggy. A memory leak is one thing, but segfaults and assertion failures... Down to brass tacks: is this thing usable in its current state?
      - stefano 16y ago
        > Down to brass tacks: is this thing usable in its current state? Experimentation and quick and dirty prototypes? Yes. Production code? No.
wingo 16y ago
Whatever seems like the most fun to you, of course. Also: there are many more possible compilation targets than ones you list.
- RiderOfGiraffes 16y ago
  Yes, exactly, and that's why I was asking for recommendations and suggestions. I have been largely unable to find anything that gives a sensible overview of the technology and the various trade-offs. Hence my question, although it seems like this is the wrong audience/forum.
  - wingo 16y ago
    There is no technical answer. OK, there are terrible answers, but not everyone agrees about which those are. In the end making a compiler is a world-affecting act: both to your own, and to those of others. You have to decide socially which group you want to associate yourself with, what kind of world you want.
JoachimSchipper 16y ago
For the more static languages, LLVM seems hot and well-supported right now. There is a rich tradition of compiling via C, with good and bad results. Gambit Scheme compiles via C and is one of the fastest Scheme systems around, with good interoperability via C. The Glassgow Haskell Compiler can also compile via C, but that's, AFAIK, an unmaintainable mess (search for "evil mangler").

avar 16y ago

Parrot's been claiming that it's slow and incomplete now, but a solution to that is just around the corner for a few years. Maybe that's true, but I think that'd be the main concern of any compiler writer thinking of targeting it. It's not a mature platform with known pros and cons, unlike the JVM or LLVM. I hope it all turns out for the best and Parrot delivers on its promises. But I can see why e.g. the PHP team isn't rushing to target it given the state of its native languages.

j_baker 16y ago
These things take a long time. Heck, it might even be a bit early to call LLVM mature. Sure, it supports a C and C++ compiler, but I don't think it has anything production-ready for much else.
- avar 16y ago
  It's in extensive use by Apple on the iPhone and in XCode, and outside Apple. The JVM is also well understood and widely deployed. By comparison the Parrot project with the widest use is Rakudo, which is still just at a testing stage. Maybe there's some larger user of Parrot that I haven't heard about, so correct me if I'm wrong.
  - amalter 16y ago
    fyi - with the JDK7 - the JVM can also target the LLVM (for JIT'ing) through Project Zero (http://openjdk.java.net/projects/zero/ http://openjdk.java.net/projects/zero/) One Bytecode to rule them all, One Bytecode to find them, One Bytecodeto bring them all and in the darkness bind them :-)
  - chromatic 16y ago
    Lua 5.2 has been feature complete on Parrot for years. Like LLVM and the JVM, we'll keep tuning and improving and fixing bugs and adding features to make language implementation easier, but the correlation between "maturity" and "use" is strong.