I'm looking at the following module: https://hackage.haskell.org/package/boxes-0.1.4/docs/src/Text-PrettyPrint-Boxes.html
Which has contents of:
module Text.PrettyPrint.Boxes
( -- * Constructing boxes
#ifdef TESTING
Box(Box, content)
#else
Box
#endif
How can I enable / define the TESTING value - for development purposes? Ideally I'd like to have this built / enabled within a GHCi session.
I have to correct myself - the comment I gave is totally and utterly wrong.
> git clone git://github.com/treeowl/boxes.git
> cd boxes
> stack init
> stack ghci --ghc-options=-DTESTING
split-0.2.3.2: using precompiled package
boxes-0.1.4: configure (lib)
Configuring boxes-0.1.4...
boxes-0.1.4: initial-build-steps (lib)
Completed 2 action(s).
Configuring GHCi with the following packages: boxes
GHCi, version 8.0.2: http://www.haskell.org/ghc/ :? for help
Loaded GHCi configuration from ...
[1 of 1] Compiling Text.PrettyPrint.Boxes ( .../boxes/Text/PrettyPrint/Boxes.hs, interpreted )
Ok, modules loaded: Text.PrettyPrint.Boxes.
Loaded GHCi configuration from /tmp/ghci28386/ghci-script
*Text.PrettyPrint.Boxes Text.PrettyPrint.Boxes> :t content
content :: Box -> Content
just works fine.
Related
I try to setup a stack based Haskell IDE with vscode and start with a small project created with stack init and then added a second module in src and added some dependencies in package.yaml. It builds ok but when I start stack ghci I have warnings:
Warning: Multiple files use the same module name:
* Paths_primo found at the following paths
* /home/frank/Workspace11/primo/.stack-work/dist/x86_64-linux-tinfo6/Cabal-3.2.1.0/build/autogen/Paths_primo.hs (primo:lib)
* /home/frank/Workspace11/primo/.stack-work/dist/x86_64-linux-tinfo6/Cabal-3.2.1.0/build/primo-exe/autogen/Paths_primo.hs (primo:exe:primo-exe)
* * * * * * * *
GHCi, version 8.10.4: https://www.haskell.org/ghc/ :? for help
[1 of 3] Compiling Lib ( /home/frank/Workspace11/primo/src/Lib.hs, interpreted )
[2 of 3] Compiling YamlRead ( /home/frank/Workspace11/primo/src/YamlRead.hs, interpreted )
[3 of 3] Compiling Main ( /home/frank/Workspace11/primo/app/Main.hs, interpreted )
Ok, three modules loaded.
There seems to be a confusion with autogen and with Paths_primo (primo is the name of the package). What am I doing wrong?
General question: what is the correct way to clean a stack project to "start over" after some experimentation? Is is correct to delete the cabal file and the stack-work directory. Waht is with stack.yaml and 'stack.yaml.lock`?
This appears to be a harmless warning reported at Stack issue #5439, whose underlying cause is hpack issue #303. A workaround to get rid of the warning is disabling the generation of the Paths_ module for your primo-exe executable, by adding the following to its section in package.yaml:
when:
- condition: false
other-modules: Paths_primo
I'm using stack ghci to start my REPL, based on the answer I got for my question on how to import a module installed with stack. This works fine, but I get initially a warning message Note: No local targets specified, so a plain ghci will be started with no package hiding or package options., followed by a bunch of suggestions about package hiding and options. My guess is that this is because I have not used stack init to setup a project, since I am still in the "playing around and learning" state and don't want a project yet. I have not found an explanation about the meaning of 'no local targets', but the effect to start a plain ghci is exactly what I want at that point. Is there a way to suppress this message? I looked at stack --help, but could not find something suitable.
As the Note (not warning) suggests, a plain ghci is started, which is rather uncommon situation when working with stack.
~$ stack ghci
Note: No local targets specified, so a plain ghci will be started with no package hiding or package options.
You are using snapshot: lts-14.12
If you want to use package hiding and options, then you can try one of the following:
* If you want to start a different project configuration than /home/username/.stack/global-project/stack.yaml, then you can use stack init to create a new stack.yaml for the packages in the
current directory.
* If you want to use the project configuration at /home/username/.stack/global-project/stack.yaml, then you can add to its 'packages' field.
Configuring GHCi with the following packages:
GHCi, version 8.6.5: http://www.haskell.org/ghc/ :? for help
Loaded GHCi configuration from /tmp/haskell-stack-ghci/2a3bbd58/ghci-script
Prelude>
This means though that all you need to do to get the same behavior without the Note is just start ghci manually in the context of global stack environment:
~$ stack exec -- ghci
GHCi, version 8.6.5: http://www.haskell.org/ghc/ :? for help
Prelude>
In case that you want to make sure some package is installed for "playing around and learning" in the ghci session you can supply them as --package arguments
~$ stack exec --package massiv -- ghci
atomic-primops> using precompiled package
cabal-doctest > using precompiled package
scheduler > using precompiled package
massiv > using precompiled package
Completed 4 action(s).
GHCi, version 8.6.5: http://www.haskell.org/ghc/ :? for help
Prelude> import Data.Massiv.Array
Prelude Data.Massiv.Array>
stack exec --ghci as in lehins's answer did not work for me, but stack exec ghci did.
Is it possible to configure stack ghci similar to the way ghci is configured via the ~/.ghci file?
Currently stack ghci does not pick up the settings in the ~/.ghci file.
I'm looking into setting the prompt to be a lambda instead of the loaded modules:
:set prompt "\ESC[33m\STXλ> \ESC[m\STX"
Update
[neo#nixos:~/HaskellLearning/IdeTest]$ stack ghci The following GHC
options are incompatible with GHCi and have not been passed to it:
-threaded Configuring GHCi with the following packages: IdeTest Using main module: 1. Package `IdeTest' component exe:IdeTest-exe with
main-is file: /home/neo/HaskellLearning/IdeTest/app/Main.hs GHCi,
version 8.2.2: http://www.haskell.org/ghc/ :? for help Loaded GHCi
configuration from /home/neo/HaskellLearning/IdeTest/.ghci Loaded GHCi
configuration from /home/neo/.ghci [1 of 9] Compiling Ch13
( /home/neo/HaskellLearning/IdeTest/src/Ch13.hs, interpreted ) [2 of
9] Compiling Ch15 (
/home/neo/HaskellLearning/IdeTest/src/Ch15.hs, interpreted ) [3 of 9]
Compiling Ch17 (
/home/neo/HaskellLearning/IdeTest/src/Ch17.hs, interpreted ) ... Ok, 9
modules loaded. Loaded GHCi configuration from
/run/user/1000/ghci31082/ghci-script
*Main Ch13 Ch15 Ch17 Functor HelloError Lib Phone SemigroupAndMonoid>
None of the other 2 configurations mentioned does anything regarding changing the prompt.
Try to put your config under:
~/.ghc/ghci.conf
Works for me on Ubuntu 16.04.
I created a new project and, as you can see, it even downloaded a brand new build plan for lts-7.4, which as you can see uses ghc-8.0.1.
But when running stack ghci, it built the project with GHC 7.10, and dropped me in a 7.10 ghci shell.
dario#curie /tmp> stack new foo
Downloading template "new-template" to create project "foo" in foo/ ...
Looking for .cabal or package.yaml files to use to init the project.
Using cabal packages:
- foo/foo.cabal
Selecting the best among 9 snapshots...
Downloaded lts-7.4 build plan.
* Matches lts-7.4
Selected resolver: lts-7.4
Initialising configuration using resolver: lts-7.4
Total number of user packages considered: 1
Writing configuration to file: foo/stack.yaml
All done.
dario#curie /tmp> cd foo
dario#curie /t/foo> stack ghci
foo-0.1.0.0: configure
Configuring foo-0.1.0.0...
foo-0.1.0.0: build
Preprocessing library foo-0.1.0.0...
[1 of 1] Compiling Lib ( src/Lib.hs, .stack-work/dist/x86_64-linux/Cabal-1.22.5.0/build/Lib.o )
In-place registering foo-0.1.0.0...
Preprocessing executable 'foo-exe' for foo-0.1.0.0...
[1 of 1] Compiling Main ( app/Main.hs, .stack-work/dist/x86_64-linux/Cabal-1.22.5.0/build/foo-exe/foo-exe-tmp/Main.o )
Linking .stack-work/dist/x86_64-linux/Cabal-1.22.5.0/build/foo-exe/foo-exe ...
foo-0.1.0.0: copy/register
Installing library in
/tmp/foo/.stack-work/install/x86_64-linux/lts-7.4/7.10.3/lib/x86_64-linux-ghc-7.10.3/foo-0.1.0.0-6bylsnNRJPuHxByS3dKqs5
Installing executable(s) in
/tmp/foo/.stack-work/install/x86_64-linux/lts-7.4/7.10.3/bin
Registering foo-0.1.0.0...
The following GHC options are incompatible with GHCi and have not been passed to it: -threaded
Using main module: 1. Package `foo' component exe:foo-exe with main-is file: /tmp/foo/app/Main.hs
Configuring GHCi with the following packages: foo
GHCi, version 7.10.3: http://www.haskell.org/ghc/ :? for help
[1 of 1] Compiling Lib ( /tmp/foo/src/Lib.hs, interpreted )
Ok, modules loaded: Lib.
[2 of 2] Compiling Main ( /tmp/foo/app/Main.hs, interpreted )
Ok, modules loaded: Lib, Main.
>
I always relied on the assumption that for every stackage snapshot, stack would use only one version of GHC, am I wrong?
I don't have system-ghc: true in my config, and the faq doesn't mention many other alternatives
This is the output of stack path:
dario#curie /t/foo> stack path
stack-root: /home/dario/.stack
project-root: /tmp/foo
config-location: /tmp/foo/stack.yaml
bin-path: /home/dario/.stack/snapshots/x86_64-linux/lts-7.4/7.10.3/bin:/home/dario/.stack/programs/x86_64-linux/ghc-8.0.1/bin:/home/dario/Applications/bin:/home/dario/.rbenv/shims:/home/dario/.cabal/bin:/home/dario/.nix-profile/bin:/home/dario/.nix-profile/sbin:/home/dario/.sdkman/candidates/grails/current/bi n:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/usr/lib/jvm/java-8-oracle/bin:/usr/lib/jvm/java-8-oracle/db/bin:/usr/lib/jvm/java-8-oracle/jre/bin:/home/dario/.local/bin:/home/dario/.nix-profile/bin
programs: /home/dario/.stack/programs/x86_64-linux
compiler-exe: /usr/bin/ghc
compiler-bin: /usr/bin
local-bin: /home/dario/.local/bin
extra-include-dirs:
extra-library-dirs:
snapshot-pkg-db: /home/dario/.stack/snapshots/x86_64-linux/lts-7.4/7.10.3/pkgdb
local-pkg-db: /tmp/foo/.stack-work/install/x86_64-linux/lts-7.4/7.10.3/pkgdb
global-pkg-db: /var/lib/ghc/package.conf.d
ghc-package-path: /tmp/foo/.stack-work/install/x86_64-linux/lts-7.4/7.10.3/pkgdb:/home/dario/.stack/snapshots/x86_64-linux/lts-7.4/7.10.3/pkgdb:/var/lib/ghc/package.conf.d
snapshot-install-root: /home/dario/.stack/snapshots/x86_64-linux/lts-7.4/7.10.3
local-install-root: /tmp/foo/.stack-work/install/x86_64-linux/lts-7.4/7.10.3
snapshot-doc-root: /home/dario/.stack/snapshots/x86_64-linux/lts-7.4/7.10.3/doc
local-doc-root: /tmp/foo/.stack-work/install/x86_64-linux/lts-7.4/7.10.3/doc
dist-dir: .stack-work/dist/x86_64-linux/Cabal-1.22.5.0
local-hpc-root: /tmp/foo/.stack-work/install/x86_64-linux/lts-7.4/7.10.3/hpc
local-bin-path: /home/dario/.local/bin
ghc-paths: /home/dario/.stack/programs/x86_64-linux
dario#curie /t/foo> echo $PATH
/home/dario/Applications/bin /home/dario/.rbenv/shims /home/dario/.cabal/bin /home/dario/.nix-profile/bin /home/dario/.nix-profile/sbin /home/dario/.sdkman/candidates/grails/current/bin /usr/local/sbin /usr/local/bin /usr/sbin /usr/bin /sbin /bin /usr/games /usr/local/games /snap/bin /usr/lib/jvm/java-8-oracle/bin /usr/lib/jvm/java-8-oracle/db/bin /usr/lib/jvm/java-8-oracle/jre/bin /home/dario/.local/bin /home/dario/.nix-profile/bin
I rely on the lts determining the version of ghc in use also for CI, so it's a bit worrying if my assumption doesn't hold (anymore?)
(I'm running stack Version 1.2.0 x86_64 hpack-0.14.0)
This is the output of stack setup
dario#curie /t/foo> stack setup
stack will use a sandboxed GHC it installed
For more information on paths, see 'stack path' and 'stack exec env'
To use this GHC and packages outside of a project, consider using:
stack ghc, stack ghci, stack runghc, or stack exec
I realized that this was due to the faulty way in which I "worked around" this issue:
https://github.com/commercialhaskell/stack/issues/2712
I might open it as another bug report, but it's definitely less important/interesting than fixing #2712
Is there a way to load a package(s) using Stack in GHCI and play around with it ?
So, that when the ghci is loaded, we can import the modules and see it's type signature, etc.
For the packages present in Stackage,
$ stack ghci --package unix-time
And this will give you a repl with the package unix-time loaded in it:
Run from outside a project, using implicit global project config
Using resolver: lts-6.14 from implicit global project's config file: /home/sibi/.stack/global-project/stack.yaml
GHCi, version 7.10.3: http://www.haskell.org/ghc/ :? for help
λ> import Data.UnixTime
λ> :t getUnixTime
getUnixTime :: IO UnixTime
For multiple packages:
$ stack ghci --package unix-time --package download
Run from outside a project, using implicit global project config
Using resolver: lts-6.14 from implicit global project's config file: /home/sibi/.stack/global-project/stack.yaml
tagsoup-0.13.10: using precompiled package
xml-1.3.14: using precompiled package
time-locale-compat-0.1.1.3: using precompiled package
feed-0.3.11.1: download
feed-0.3.11.1: configure
feed-0.3.11.1: build
feed-0.3.11.1: copy/register
download-0.3.2.4: download
download-0.3.2.4: configure
download-0.3.2.4: build
download-0.3.2.4: copy/register
Completed 5 action(s).
Configuring GHCi with the following packages:
GHCi, version 7.10.3: http://www.haskell.org/ghc/ :? for help
Ok, modules loaded: none.
λ> import Network.Download
λ>