Add ci/cd support

.github/workflows/ci.yml

@@ -0,0 +1,73 @@
+name: CI
+
+# Trigger the workflow on push or pull request, but only for the main branch
+on:
+  pull_request:
+    branches: [ "main" ]
+  push:
+    branches: [ "main" ]
+
+jobs:
+  ghc:
+    name: "GHC ${{ matrix.ghc }} on ${{ matrix.os }}"
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        ghc: ['8.10', '9.2', '9.8', '9.10', '9.12']
+        exclude:
+          - os: macos-latest
+            ghc: '8.10'  # ghc-8.10 does not support ARM
+      fail-fast: false
+    steps:
+      - name: Checkout base repo
+        uses: actions/checkout@v4
+
+      - name: Set up Haskell
+        id: setup-haskell
+        uses: haskell-actions/setup@v2
+        with:
+          ghc-version: ${{ matrix.ghc }}
+          cabal-version: 'latest'
+
+      - name: Configure
+        run: cabal new-configure
+
+      - name: Freeze
+        run: cabal freeze
+
+      - name: Cache
+        uses: actions/cache@v4
+        with:
+          path: ${{ steps.setup-haskell.outputs.cabal-store }}
+          key: ${{ runner.os }}-${{ matrix.ghc }}-${{ hashFiles('cabal.project.freeze') }}
+          restore-keys: ${{ runner.os }}-${{ matrix.ghc }}-
+
+      - name: Build
+        run: cabal build
+
+  mhs:
+    runs-on: ubuntu-latest
+    steps:
+      - name: checkout mhs repo
+        uses: actions/checkout@v4
+        with:
+          repository: augustss/MicroHs
+          ref: v0.14.15.0
+          path: mhs
+
+      - name: make and install mhs
+        run: |
+          cd mhs
+          make minstall
+
+      - name: checkout transformers repo
+        uses: actions/checkout@v4
+        with:
+          path: transformers
+
+      - name: compile and install transformers package
+        run: |
+          PATH="$HOME/.mcabal/bin:$PATH"
+          cd transformers
+          mcabal install