7 ms·

Python 3 implementation in Haskell

143 points by marshallp 15y ago

judofyr 15y ago
See also: http://news.ycombinator.com/item?id=1390889 http://news.ycombinator.com/item?id=1390889
flazzarino 15y ago
but will it blend?
tresta 15y ago
Hmmm... won't install with ghc 7.0.4: $ cabal install berp Resolving dependencies... cabal: dependencies conflict: ghc-7.0.4 requires containers ==0.4.0.0 however containers-0.4.0.0 was excluded because berp-0.0.2 requires containers <0.4
- exDM69 15y ago
  This is pretty usual when it comes to major revision changes in the compiler or standard library with many languages. This is what you should do: 1. checkout berp from GitHub 2. try to build using cabal in the checked out source tree 3. if there are failing dependencies, hack Cabal build files. this case is probably trivial and berp developers have left containers < 0.4 without a good reason (I may be wrong here, see what's changed in the "containers" package). 4. go to step 2, repeat until software is built 5. submit the change to github, file pull request
  - wbhart 15y ago
    After three hours of trying to install this with GHC 6.12.1 and GHC 7.0.3 I have given up. The problem isn't with berp .cabal files but with dependencies of berp. ghc-7.0.3 requires containers ==0.4.0.0 language-python requires containers ==0.3.0.0 ghc-6.12.1 requires directory ==1.0.1.0 language-python requires directory ==1.0.1.2 Fetching and unpacking language-python and changing the dependencies manually doesn't appear to fix the problem, for reasons I do not understand.
    - Symmetry 15y ago
      This sounds sadly like my experiences trying to get the Yi editor to install. I love Haskell in theory, but the build system is so painful if you aren't an expert!
      - exDM69 15y ago
        The same can be said about Ruby, except that my experiences with Ruby are worse than with Haskell. With Haskell, you can get a pretty nice "batteries included" setup by installing the latest Haskell platform package. With Ruby, you have to learn to use rvm, bundler and whatnot just to get a recent version of Ruby installed. Many distributions ship with quite old versions of Ruby and the Ruby official release tarballs have been unreliable (version number doesn't change, tarball contents does, etc). Lots of languages seem to suffer from similar problems.
    - Peaker 15y ago
      When you "cabal unpack language-python" and fix the dependencies, make sure you boost its minor version number (e.g: from: 1.0.3 to 1.0.3.1), otherwise cabal-install will ignore your custom install of the package and will revert to the one from the repositories. cabal-install is a big hurdle -- must be improved for faster Haskell adoption.
    - wbhart 15y ago
      There is a workaround for the issues with language-python. One can do: cabal fetch language-python cabal unpack language-python edit the language-python.cabal file updating the containers dependency to 0.4.0.0 then change the version number of language-python itself to 0.3.3 cabal configure cabal install However, this will not fix the more obtuse problem: Warning: This package indirectly depends on multiple versions of the same package. This is highly likely to cause a compile failure. package haskell98-1.1.0.1 requires process-1.0.1.5 package ghc-7.0.3 requires process-1.0.1.5 package Cabal-1.10.1.0 requires process-1.0.1.5 package berpinterpreter-0.0.3 requires process-1.0.1.5 I believe the only solution for this problem is to rebuild the entire Haskell platform from source, and if that fails, to format and reload the entire machine. But you know, keep voting this thread up because Hackhell is awesome.
- yoklov 15y ago
  Welcome to the dll hell-style package management system of hackage.
marcf 15y ago
How fast is it?
- wbhart 15y ago
  Mostly it doesn't actually work. But the one trivial example I tried the berp interpreter was something like 1000 times slower than Python.
chbrosso 15y ago
Last update was in May 2010...
- treo 15y ago
  Last commit on August 04, 2011. https://github.com/bjpop/berp https://github.com/bjpop/berp
  - wbhart 15y ago
    There is a commit to the new-identity branch on Oct 19th 2011.
sp332 15y ago
Some discussion of implementation on github: https://github.com/bjpop/berp/wiki/Developing-Berp https://github.com/bjpop/berp/wiki/Developing-Berp
- DasIch 15y ago
  Which shows that this implementation doesn't support imports, keyword arguments, metaclasses, eval and variable scope annotations. This might have been a nice exercise but it is completely unusable as a serious implementation.
  - deleted 15y ago
    [deleted]
    - alphadogg 15y ago
      That's uselessly snarky. I agree with DasIch; call it what it is: a partial implementation of Python3. I read the page in the link and thought someone created a full implementation.
  - egonschiele 15y ago
    > Please note that Berp is currently in a very early stage of development. Many aspects of Python 3 are not yet implemented, and there are lots of rough edges to the code.
- deleted 15y ago
  [deleted]
mulander 15y ago
CLPython (http://common-lisp.net/project/clpython/) is an open-source implementation of Python written in Common Lisp. It bridges the Python and Lisp worlds, so you can: * access Python libraries from Lisp; * access Lisp libraries from Python. Runs on 6 different CL implementations. Like Berp it can interpret and compile if the underlying CL implementation supports compilation.
treeform 15y ago
I wander if it adds any of Haskell's lazy and thread features?
- treeform 15y ago
  To answer my own question it looks like it supports call/cc https://github.com/bjpop/berp/blob/master/test/regression/features/callCC/callCC_continuation_returned.py https://github.com/bjpop/berp/blob/master/test/regression/fe... tail calls https://github.com/bjpop/berp/blob/master/test/regression/features/tail_call/tail_call_method.py https://github.com/bjpop/berp/blob/master/test/regression/fe... So those features are cool at-least...

143 points by marshallp 15y ago

judofyr 15y ago

See also: http://news.ycombinator.com/item?id=1390889 http://news.ycombinator.com/item?id=1390889

flazzarino 15y ago

but will it blend?

tresta 15y ago

Hmmm... won't install with ghc 7.0.4: $ cabal install berp Resolving dependencies... cabal: dependencies conflict: ghc-7.0.4 requires containers ==0.4.0.0 however containers-0.4.0.0 was excluded because berp-0.0.2 requires containers <0.4

exDM69 15y ago
This is pretty usual when it comes to major revision changes in the compiler or standard library with many languages. This is what you should do: 1. checkout berp from GitHub 2. try to build using cabal in the checked out source tree 3. if there are failing dependencies, hack Cabal build files. this case is probably trivial and berp developers have left containers < 0.4 without a good reason (I may be wrong here, see what's changed in the "containers" package). 4. go to step 2, repeat until software is built 5. submit the change to github, file pull request
- wbhart 15y ago
  After three hours of trying to install this with GHC 6.12.1 and GHC 7.0.3 I have given up. The problem isn't with berp .cabal files but with dependencies of berp. ghc-7.0.3 requires containers ==0.4.0.0 language-python requires containers ==0.3.0.0 ghc-6.12.1 requires directory ==1.0.1.0 language-python requires directory ==1.0.1.2 Fetching and unpacking language-python and changing the dependencies manually doesn't appear to fix the problem, for reasons I do not understand.
  - Symmetry 15y ago
    This sounds sadly like my experiences trying to get the Yi editor to install. I love Haskell in theory, but the build system is so painful if you aren't an expert!
    - exDM69 15y ago
      The same can be said about Ruby, except that my experiences with Ruby are worse than with Haskell. With Haskell, you can get a pretty nice "batteries included" setup by installing the latest Haskell platform package. With Ruby, you have to learn to use rvm, bundler and whatnot just to get a recent version of Ruby installed. Many distributions ship with quite old versions of Ruby and the Ruby official release tarballs have been unreliable (version number doesn't change, tarball contents does, etc). Lots of languages seem to suffer from similar problems.
  - Peaker 15y ago
    When you "cabal unpack language-python" and fix the dependencies, make sure you boost its minor version number (e.g: from: 1.0.3 to 1.0.3.1), otherwise cabal-install will ignore your custom install of the package and will revert to the one from the repositories. cabal-install is a big hurdle -- must be improved for faster Haskell adoption.
  - wbhart 15y ago
    There is a workaround for the issues with language-python. One can do: cabal fetch language-python cabal unpack language-python edit the language-python.cabal file updating the containers dependency to 0.4.0.0 then change the version number of language-python itself to 0.3.3 cabal configure cabal install However, this will not fix the more obtuse problem: Warning: This package indirectly depends on multiple versions of the same package. This is highly likely to cause a compile failure. package haskell98-1.1.0.1 requires process-1.0.1.5 package ghc-7.0.3 requires process-1.0.1.5 package Cabal-1.10.1.0 requires process-1.0.1.5 package berpinterpreter-0.0.3 requires process-1.0.1.5 I believe the only solution for this problem is to rebuild the entire Haskell platform from source, and if that fails, to format and reload the entire machine. But you know, keep voting this thread up because Hackhell is awesome.
yoklov 15y ago
Welcome to the dll hell-style package management system of hackage.

marcf 15y ago

How fast is it?

wbhart 15y ago
Mostly it doesn't actually work. But the one trivial example I tried the berp interpreter was something like 1000 times slower than Python.

chbrosso 15y ago

Last update was in May 2010...

treo 15y ago
Last commit on August 04, 2011. https://github.com/bjpop/berp https://github.com/bjpop/berp
- wbhart 15y ago
  There is a commit to the new-identity branch on Oct 19th 2011.

sp332 15y ago

Some discussion of implementation on github: https://github.com/bjpop/berp/wiki/Developing-Berp https://github.com/bjpop/berp/wiki/Developing-Berp

DasIch 15y ago
Which shows that this implementation doesn't support imports, keyword arguments, metaclasses, eval and variable scope annotations. This might have been a nice exercise but it is completely unusable as a serious implementation.
- deleted 15y ago
  [deleted]
  - alphadogg 15y ago
    That's uselessly snarky. I agree with DasIch; call it what it is: a partial implementation of Python3. I read the page in the link and thought someone created a full implementation.
- egonschiele 15y ago
  > Please note that Berp is currently in a very early stage of development. Many aspects of Python 3 are not yet implemented, and there are lots of rough edges to the code.
deleted 15y ago
[deleted]

mulander 15y ago

CLPython (http://common-lisp.net/project/clpython/) is an open-source implementation of Python written in Common Lisp. It bridges the Python and Lisp worlds, so you can: * access Python libraries from Lisp; * access Lisp libraries from Python. Runs on 6 different CL implementations. Like Berp it can interpret and compile if the underlying CL implementation supports compilation.

treeform 15y ago

I wander if it adds any of Haskell's lazy and thread features?

treeform 15y ago
To answer my own question it looks like it supports call/cc https://github.com/bjpop/berp/blob/master/test/regression/features/callCC/callCC_continuation_returned.py https://github.com/bjpop/berp/blob/master/test/regression/fe... tail calls https://github.com/bjpop/berp/blob/master/test/regression/features/tail_call/tail_call_method.py https://github.com/bjpop/berp/blob/master/test/regression/fe... So those features are cool at-least...