Add multisets #2004

	name: Haskell tests

	on:
	push:
	branches: [ main ]
	pull_request:
	branches: [ main ]

	env:
	DEX_CI: 1

	concurrency:
	group: haskell-${{ github.head_ref \|\| github.run_id }}
	cancel-in-progress: true

	jobs:
	build:
	runs-on: ${{ matrix.os }}
	strategy:
	matrix:
	os: [ubuntu-20.04, macos-latest]
	include:
	- os: macos-latest
	install_deps: brew install llvm@12 pkg-config wget gzip coreutils
	path_extension: $(brew --prefix llvm@12)/bin
	- os: ubuntu-20.04
	install_deps: sudo apt-get install llvm-12-tools llvm-12-dev pkg-config wget gzip wamerican
	path_extension: /usr/lib/llvm-12/bin

	steps:
	- name: Checkout the repository
	uses: actions/checkout@v2

	- name: Cache
	uses: actions/cache@v2
	with:
	path: \|
	~/.stack
	~/.ghcup/ghc/8.10.7
	$GITHUB_WORKSPACE/.stack-work
	$GITHUB_WORKSPACE/.stack-work-test
	$GITHUB_WORKSPACE/examples/t10k-images-idx3-ubyte
	$GITHUB_WORKSPACE/examples/t10k-labels-idx1-ubyte

	key: ${{ runner.os }}-v5-${{ hashFiles('*/.cabal', 'stack*.yaml') }}
	restore-keys: ${{ runner.os }}-v5-

	- name: Install system dependencies
	run: \|
	${{ matrix.install_deps }}
	if [[ "$OSTYPE" == "darwin"* ]]; then ghcup install ghc 8.10.7; fi
	echo "${{ matrix.path_extension }}" >> $GITHUB_PATH

	# This step is a workaround.
	# See issue for context: https://github.com/actions/cache/issues/445
	- name: Remove cached Setup executables
	run: rm -rf ~/.stack/setup-exe-cache
	if: runner.os == 'macOS'

	- name: Build, treating warnings as errors
	run: make build-ci
	if: runner.os == 'Linux'

	- name: Build
	run: make build

	- name: Run tests
	run: make tests

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