Recommended tooling for PureScript applications in 2019

@Benjmhart that’s a good point about Halogen and hot reloading. Thanks for the link! I’ve also added pscid to the list of tooling, because I’d forgotten about it – I find the compile / error loop to be quite fast in VSCode and Vim with the IDE server, but I’m not waiting on Parcel or Webpack.

@cprussin That’s good to learn about. I wasn’t aware you could do this with Yarn, and it’s one more reason to move away from npm / npx. I’ve updated the post to include this information.

At this point you can easily get away with managing a PureScript project with only Yarn installed and then using it to install the compiler, Spago, and Parcel. That’s a reasonably lean set of tools. I have a soft spot for managing everything with Nix, but I don’t think that’s a reasonable suggestion as the default for most people.

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Wow this is great. I vote the post is placed somewhere on the site


I’m not sure how opinionated wants to be about tooling, but there is at least a movement to recommend Spago by default.

On the one hand I think it makes sense to add a file to the documentation repository for web-specific tooling which recommends Yarn + Spago + Parcel, but on the other, this stuff is largely a matter of opinion, is project-specific, and changes fast. That makes me ambivalent about any official endorsements.

On one hand, I like how unopinionated PS is, but on the other I don’t :slight_smile: I think a lot of people don’t know how to get started, and yarn + spago + parcel is a great way to get going. Having this list here is great, but I use PS every day and I barely ever visit this forum. I’d imagine new users are similar.

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You make a good point. I’ve opened an issue on the documentation repository relating to this.

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Fantastic post. It takes a while to put all the pieces together. Great to see all this in one place!

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I put together a minimal repo for anyone wanting a quick start with the tooling recommended in the thread. I left zephyr out, as I can’t find any docs on using it with spago. I also left out npx and psvm.


Nice. What’s the point in mentioning tmux though?
Not everyone uses it, and it is unrelated to PS, which is not obvious for a linux and PS newcomer.

I’m a new user working through this guide and two other “official” guides:

I’ve found this guide to be the most helpful. Should the above two references be updated to follow this workflow?

I’m attempting to update the first guide, and want to clarify what prereqs are needed to launch the repl.

Edit: Found yarn spago repl, so disregard the rest of this message.

Should purescript still be installed with npm or yarn globally, or should I find a way to temporarily add the project’s specific version (located in node_modules/purescript/purs.bin) to $PATH?

Here’s a log of what happens when attempting to launch the repl if purescript is only installed via yarn as described in the first post:

> purs repl
Command 'purs' not found

> node_modules/purescript/purs.bin --version

> node_modules/purescript/purs.bin repl
purs repl: No input files; try running `pulp psci` instead.
For help getting started, visit
Usage: For basic information, try the `--help' option.

> pulp psci
Command 'pulp' not found
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Yea, looks like the yarn ... commands are what you’re looking for if you want to run locally-installed tooling in your project. As far as updating the getting started guides, I opened an issue about adding this guide, but it hasn’t seen much progress yet.

Ultimately I think of this as my recommendation, but not necessarily something that would work as an official ‘PureScript’ stance. Still, I think it deserves a place somewhere in the official docs.

If you’re new to PureScript, you might find my repo helpful as well:


This thread is super helpful, thank you all! Just thought I’d offer my current WIP for using Purescript with Nix:

Unfortunately, I’m struggling to get spago bundle-app working (see default.nix):

purs bundle: No input files.
[error] Bundle failed.

Please let me know if you have suggestions!

Edit: that error was due to missing \ on line 28. Now I get a new error:

Couldn't find a CommonJS module for the specified main module: Example.Main
[error] Bundle failed.

I think this is because there is no Example in dist, but if I try to call spago without --no-install --no-build, it fails due to no internet connectivity in sandbox.

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Got it working! Here’s my nix derivation:

with import <nixpkgs> {};

  spagoPkgs = import ./spago-packages.nix { inherit pkgs; };
mkYarnPackage rec {
  name = "purescript-nix-example";
  src = ./.;
  packageJSON = ./package.json;
  yarnLock = ./yarn.lock;

  nativeBuildInputs = [ purescript nodejs-12_x ];

  postBuild = ''
    ${purescript}/bin/purs compile "$src/**/*.purs" ${builtins.toString
        (x: ''"${x.outPath}/src/**/*.purs"'')
        (builtins.attrValues spagoPkgs.inputs))}
    cp -r $src/assets ./

  postFixup = ''
    ${spago}/bin/spago bundle-app --no-install \
      --no-build --main Example.Main --to dist/app.js
    mkdir -p $out/dist
    cp -r dist $out/
    ln -s $out/libexec/${name}/node_modules .
    ${nodejs-12_x}/bin/node node_modules/.bin/parcel \
      build assets/*.html --out-dir $out/dist/

  meta = with stdenv.lib; {
    description = "Example for building Purescript Halogen app with Nix.";
    homepage = "";
    maintainers = with maintainers; [ tbenst ];

Full code here.


I agree that more opinionation would really improve the new user experience.

There’s currently no clear pathway to getting a web app running from the landing page, even for users who read through both the quick start guide and the documentation page.

Something like create-react-app would be great. For now, it could just be a template clone command.

This would favor a particular toolchain and framework, but I don’t think that’s worse than the existing alternative of no direction. The unfairness could be partially remedied with a link to a “more frameworks” page.

Having official templates would also help focus everyone’s maintenance efforts and be a consistent springboard for tutorials.

For example, it would be nice if we could arrive at best practices from each of these 7 reasonable Halogen templates and track one of them under the purescript-contrib org.


Edit: Found some additional discourse discussion on create-react-app:

Also, here are details on how create-react-app manages templates.

We can also look to create-elm-app for inspiration, which is an excellent new user experience.

Maybe we could someday reach the state where we’re just telling new users to run one of the following:

spago init --template halogen
spago init --template react-basic-hooks
spago init --template cli
... etc.

@milesfrain great points! :clap:
I opened this issue in Spago to track the addition of the --template flag as you mentioned in your post. I’ve been holding off on tracking this because I was not sure if it was a widespread need (vs just my feeling), but it looks like it would improve UX so I’d be happy to see this happening


Does it make sense to include a link to psa? Error and warning message quality is particularly important to new users.


Yes, I think it makes sense to link to psa – and as a note, Spago uses psa by default under the hood if it’s installed.

Since this thread is about opinionated recommendations, which editor / IDE would you recommend for PureScript development?

I’m a long time Sublime Text user, but I have found the ST plugin quite lacking. There is no auto-import, the import auto-complete is close to useless, the error reporting hover window comes out once every full moon and sometimes it gets stuck completely and I have to pkill -f purs.ide.server. I might as well keep it only for the syntax highlighting and just use some other aiding tool, such as the aforementioned pscid.

I’m conversant with Python, so I might pick up the ST plugin in the future and work on it, but for now I’m still learning PureScript, so I’d like to at least know what the state of the art is.

As of 2020, which IDE has the best integration, meaning the best auto-complete, auto-import, error reporting, type information, pop-up documentation, jump to definition, and such features?

I’ve had good experiences with vscode (using PS and purty plugins). All of these features work:

  • auto-complete
  • auto-import
  • error reporting
  • type information
  • pop-up documentation
  • jump to definition
  • format-on-save

The only annoyances are:

  • Need to Restart/Reconnect the IDE server after adding new functions in one file that are used in another file.
  • None of the vim plugns in vscode are feature-complete. Workaround is to just briefly open a separate vim instance for more involved edits.

Has anyone used vim successfully for PS with the above feature set?

I mostly see VSCode or Emacs users. I use VSCode myself and it works smoothly.

As far as Vim goes I use a pretty limited feature set so I haven’t run into trouble.

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