Try to show a summary after the CI run (#300)

.github/workflows/ci.yml

@@ -12,6 +12,8 @@ permissions:
 jobs:
   build:
     name: core library
+    permissions:
+      pull-requests: write
     runs-on: ubuntu-latest
     steps:
       - name: Checkout 🛎️
@@ -32,4 +34,21 @@ jobs:
       - name: Compile Alive Examples
         run: |
           lake -R exe cache get # download cache of mathlib docs.
-          lake -R build AliveExamples
+          lake -R build AliveExamples 2>&1 | tee out
+          echo `grep theorem SSA/Projects/InstCombine/AliveStatements.lean | wc -l` > all
+          grep 'Alive.*sorry' out | wc -l > failed
+          x=$((`cat all`  -  `cat failed`)); echo $x > diff
+          echo "ALIVE_SUCCESS=$(cat diff)" >> $GITHUB_ENV
+          echo "ALIVE_ALL=$(cat all)" >> $GITHUB_ENV
+          echo "ALIVE_FAILED=$(cat failed)" >> $GITHUB_ENV
+
+      - uses: actions/github-script@v6
+        if: github.event_name == 'pull_request'
+        with:
+          script: |
+            github.rest.issues.createComment({
+              issue_number: context.issue.number,
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              body: `Alive Statistics: ${{env.ALIVE_SUCCESS}} / ${{env.ALIVE_ALL}} (${{env.ALIVE_FAILED}} failed)`
+            })