View documentation of packages installed into a cabal sandbox - haskell

Is there a way to view the documentation of any package I installed in a cabal sandbox? Currently I have a script that places the documentation in a common path so I can view it with a simple server script, but I imagine there's a better or more accepted way of doing this.
To be clear, I do not mean cabal-dev, but the sandboxing tools in the latest cabal.

If you install packages into sandbox with documentation enabled (cabal install --enable-documentation or documentation: True in ./cabal.config), the generated documentation will be put under ./.cabal-sandbox/share/doc/$arch-$os-$compiler/$pkigid. In other words, this works in the same way as with the user package DB (one exception is that a local documentation index is not created in the sandbox case - this is a known issue).

Related

Recommended approach to use Stack as global package manager

I would like to install some Haskell libraries globally, for example hindent which is used by my editor's Haskell integration. What is the recommended way to do this?
I thought that stack install hindent was the correct way to do this. However, then I wanted to update my packages and found that there was no way to do this. According to the GitHub issue report I found,
stack is concerned with managing a local build sandbox for a project. It isn't intended to be a global package manager.
There appear to be workarounds such as maintaining a dummy project with artificial dependencies on the packages I would like installed. This sounds like a terrible hack, and I have been unable to find any official documentation on what approach should actually be taken.
Installing Haskell packages using my system package manager (Homebrew) is not an option since they are not packaged.
I would have opened an issue report against Stack, however the contribution guidelines requested that I instead ask a question here under the haskell-stack tag.
Well, stack install in any project will install to ~/.local/bin therefore making whatever executable you install be globally accessible.
The global project is used when running stack without a project, it is located in ~/.stack/global-project/stack.yaml.
If you want all of your globally accessible tools to have the same dependencies (perhaps to ensure that the ghc version matches or something), then you could make a project intended to build all of these tools. It's up to you whether or not it is the "global project" - there's not much special about it, it's just a default if you run stack and aren't in a project.
In order to record "what haskell executables do I want installed globally", you might consider creating a shell file like
#!/bin/sh
stack install hindent
And then running this whenever you change the versions of the installed tools.
Also, for tools like intero that need to match the ghc version, you can do stack install --copy-compiler-tool intero, and it will be available on the PATH when stack is used with that ghc version.

How to get Cabal Sandbox to install correctly linked HTML documentation?

I created a cabal library inside a sandbox with the following commands:
cabal sandbox init
cabal init
I added the line documentation: True to cabal.config to make sure that documentation is generated, and I added a dependency to the vector package in mylib.cabal. Then I ran:
cabal install --only-dependencies
I got the following output:
/scm/hs-proj/.cabal-sandbox
Configuring primitive-0.6...
Building primitive-0.6...
Installed primitive-0.6
Configuring vector-0.10.12.3...
Building vector-0.10.12.3...
Installed vector-0.10.12.3
Updating documentation index
/scm/hs-proj/.cabal-sandbox/share/doc/x86_64-osx-ghc-7.10.1/index.html
So far so good.
When I opened the index file it contained links to a lot of packages, like:
file:///scm/hs-proj/.cabal-sandbox/share/doc/x86_64-osx-ghc-7.10.1/Data-List.html
file:///scm/hs-proj/.cabal-sandbox/share/doc/x86_64-osx-ghc-7.10.1/Data-Vector.html
But of these links pointed to any real files. Note that this is the case for the extra dependencies like vector and also for built-in packages list Data.List.
So I think I've installed the documentation incorrectly. Can someone point out how I've installed the documentation incorrectly and how to do it correctly?
It's not your fault, this is a known bug in haddock.
It only affects ghc 7.10, so a workaround could be to use ghc 7.8.4 until this is fixed.

laravel 4 suggestions about new installations

I have just installed laravel 4 using composer in my linux os. While it was downloading and installing all the packages it also gave me a lot of suggestions. It asked me to install
symfony/config
symfony/yaml
symfony/dependemcy-injection
symfony/class-loader
symfony/validator
doctrine/dbal
symfony/expression-language
doctrine/annotations
ext-phpiredis
ext-curl
ext-gmp
paer-pear/PHP_Compat
ext-intl
graylog2/gelf-php
raven/raven
doctrine/couchdb
ruflin/elastica
ext-amqp
ext-mongo
aws/aws-sdk-php
rollbar/rollbar
Should I install these things. And if I have to then how would I install them? Thanks in advance. :D
You don't have to install them for Laravel to function any differently. You should only install them if you explicitly plan on using them. The install directions are usually found on the project's github page.
All of those packages can be found on http://www.packagist.com where you will easily be able to find them, see install directions, usage, etc...
To install them, usually you'd just add the appropriate line, usually found in the documentation, to your composer.json file, run composer update and they should automatically be made available to your project.
You got suggestions for both PHP library packages (PHP code) and PHP extensions (C code).
You should only install the PHP libraries if you know you want to use them. The suggestion feature of Composer allows any developer of a package to let Composer announce on update that there might be more software that enhances the library, but is entirely optional. The description next to the package name might have details on why the package could be installed. For example, a library for FTP and HTTP access might want to use existing FTP or HTTP clients, and will announce both as suggestions. If you decide you don't need FTP access, you only require the HTTP client to be used.
You cannot install PHP extensions via Composer. Installing them usually requires some kind of administrator access to the server, and depends on which OS is installed and whether or not it allows to install these extensions as a regular software package, or needs to have the PECL install toolchain available. If a PHP library suggests a PHP extension, then this extension also is completely optional, and you probably will know that if you need that feature (like access to MongoDB), you need the PHP extension as a prerequisite, but are likely to already have it installed (which would skip this suggestion from the list because it is fulfilled).

how to iterate in snap framework without cabal install

I love the snap framework but I hate running 'cabal install' with each iteration (minor code change) I want to try out.
Is there an alternative for rapid iteration?
Start with
cabal install --reinstall -fhint snap
Then, for your project:
cabal clean
cabal configure -fdevelopment
cabal build
./dist/build/projname/projname
You shouldn't ever use cabal install for binaries that you don't want to be able to execute from arbitrary locations, anyway. You should be using cabal build for things you only want to run locally.
You will need to run cabal build and start the program again when you change Main.hs or your project's .cabal file.
If you have any further questions, comment - I'm the guy who implemented this functionality for
Snap.
Yesod provides yesod devel which automatically reloads code changes. I am not aware of a comparable capability in snap, but it is highly likely that they can reuse much of the Yesod code that does this.
Given the existence of Snap.Loader.Devel I'm guessing they might already provide something like what you are asking for, but I can't find the documentation on how to use it. The FAQ question How do I run my app in development mode still requires a cabal install; it's unclear from the docs whether you only need to do this once, or every time the code changes.

Using the --reinstall flag with cabal-dev

I'm working on the wxHaskell library, and wishing to keep my development work separate from the stable wxHaskell from hackage I'm using cabal-dev in the following manner:
I obtained the source for wxHaskell from darcs;
Because wxHaskell is comprised of three components I used cabal-dev add-source to add each one (wx, wxcore, wxdirect);
I was then able to install into a sandbox local package library by doing cabal-dev install wx, as expected, the dependencies were detected and everything built and installed.
Finally I successfully ran my test code by using ghc -package-conf to specify the location of the sandboxed package database.
The problem comes when I make modifications to the wxHaskell source. In order to build and install the updated code I have to use cabal-dev install --reinstall, which makes sense as I don't increment the version number; the build takes place and I see "Installing library in..." and "Registering..." but the changes I've made in the code aren't present in the recompiled sandbox library.
The work around I have at the moment is to delete the cabal-dev library and repeat the process every time I want to rebuild.
UPDATE: cabal-install >= 1.18 has support for sandboxes, and will be better maintained than cabal-dev going forward. Cabal-install also has better support for using add-source with sandboxes. Here's a description of the new sandboxing features in cabal-install: http://coldwa.st/e/blog/2013-07-30-Cabal-sandbox.html
Old answer:
As you found, 'add-source' is not meant for use with actively changing projects. I'm not sure that there is a good solution there either - it's difficult to track the location of an add-source'd project (there is no existing infrastructure for that, at least), and I'm not sure that's always the right thing.
Another workflow may serve you better - just use cabal-dev install, pointing to the sandbox you wish to use for future development. Recent versions of the cabal toolchain (by which I mean Cabal, cabal-install and cabal-dev) allow for this sort of thing:
$ ls
wx wxcore wxdirect
$ cabal-dev install --sandbox=<path-to-some-sandbox> ./wx ./wxcore ./wxdirect
...
(Note: I have not tested this with WX - kinks may arise that I'm unaware of!)
Assuming everything goes as expected, that will install the three packages from the local sub directories into the specified sandbox. Updating the source just means re-issuing a cabal-dev install command for the project that changed.
Keep in mind that you must either issue the repeated cabal-dev install commands in the correct order on your own, or you must use the batch command above and update version numbers accordingly.
I make no claims about this being ideal ;) but I think it's better than deleting the sandbox each time.
After some investigation I can confirm that this is a result of my misunderstanding regarding the usage of add-source, as detailed in "Using a sandbox-local Hackage" section of the README, which is given here (the strong was added by myself and indicates the reason for my misunderstanding):
Cabal-dev also allows you to use un-released packages as though they
were on hackage with cabal-dev add-source.
For example, the linux-ptrace and posix-waitpid packages were only
recently uploaded to hackage. Previously, cabal-dev was used to build
applications that depended on these two packages:
$ ls
linux-ptrace/ myProject/ posix-waitpid/
$ cd myProject
$ cabal-dev add-source ../linux-ptrace ../posix-waitpid
$ cabal-dev install
Note that cabal-dev add-source accepts a list of source locations.
Be careful, however, because packages that have been added are not
tied to their original source locations any more. Changes to the
linux-ptrace source in the above example will not be used by
myProject unless the user issues cabal-dev add-source with the
path to the linux-ptrace source again. This is similar to the
cabal install step you may do now to enable a project to make use of
changes to a dependency.

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