Tutorial bugfixes and CI integration

.github/workflows/ci.yaml

@@ -13,10 +13,10 @@ jobs:
         os: [ubuntu-18.04, macos-latest]
         include:
           - os: macos-latest
-            install_deps: brew install llvm@9 pkg-config
+            install_deps: brew install llvm@9 pkg-config wget gzip
             path_extension: $(brew --prefix llvm@9)/bin
           - os: ubuntu-18.04
-            install_deps: sudo apt-get install llvm-9-tools llvm-9-dev pkg-config
+            install_deps: sudo apt-get install llvm-9-tools llvm-9-dev pkg-config wget gzip
             path_extension: /usr/lib/llvm-9/bin
 
     runs-on: ${{ matrix.os }}
@@ -37,12 +37,22 @@ jobs:
         ${{ matrix.install_deps }}
         echo "${{ matrix.path_extension }}" >> $GITHUB_PATH
 
+    - name: Get example files
+      run: |
+        wget http://yann.lecun.com/exdb/mnist/t10k-images-idx3-ubyte.gz
+        wget http://yann.lecun.com/exdb/mnist/t10k-labels-idx1-ubyte.gz
+        gunzip t10k-images-idx3-ubyte.gz t10k-labels-idx1-ubyte.gz
+        mv t10k-images-idx3-ubyte t10k-labels-idx1-ubyte $GITHUB_WORKSPACE/examples/
+
     - name: Cache
       uses: actions/cache@v2
       with:
         path: |
           ~/.stack
           $GITHUB_WORKSPACE/.stack-work
+          $GITHUB_WORKSPACE/examples/t10k-images-idx3-ubyte
+          $GITHUB_WORKSPACE/examples/t10k-labels-idx1-ubyte
+
         key: ${{ runner.os }}-${{ hashFiles('**/*.cabal', 'stack*.yaml') }}
         restore-keys: ${{ runner.os }}-