copypaste calico example running.

src/main/scala/Main.scala

@@ -1 +1,63 @@
+import calico.*
+import calico.html.io.{*, given}
+import calico.syntax.*
+import calico.unsafe.given
+import cats.effect.*
+import cats.effect.syntax.all.*
+import cats.syntax.all.*
+import fs2.*
+import fs2.concurrent.*
+import fs2.dom.*
 
+object Main extends IOWebApp {
+  def Counter(
+      label: String,
+      initialStep: Int
+  ): Resource[IO, HtmlDivElement[IO]] =
+    SignallingRef[IO]
+      .of(initialStep)
+      .product(Channel.unbounded[IO, Int])
+      .toResource
+      .flatMap { (step, diff) =>
+        val allowedSteps = List(1, 2, 3, 5, 10)
+
+        div(
+          p(
+            "Step: ",
+            select.withSelf { self =>
+              (
+                allowedSteps
+                  .map(step => option(value := step.toString, step.toString)),
+                value <-- step.map(_.toString),
+                onChange --> {
+                  _.evalMap(_ => self.value.get)
+                    .map(_.toIntOption)
+                    .unNone
+                    .foreach(step.set)
+                }
+              )
+            }
+          ),
+          p(
+            label + ": ",
+            b(diff.stream.scanMonoid.map(_.toString).holdOptionResource),
+            " ",
+            button(
+              "-",
+              onClick --> {
+                _.evalMap(_ => step.get).map(-1 * _).foreach(diff.send(_).void)
+              }
+            ),
+            button(
+              "+",
+              onClick --> (_.evalMap(_ => step.get).foreach(diff.send(_).void))
+            )
+          )
+        )
+      }
+
+  def render: Resource[IO, HtmlDivElement[IO]] = div(
+    h1("Let's count!"),
+    Counter("Sheep", initialStep = 3)
+  )
+}