add vis/bar

1 files changed, 41 insertions, 0 deletions

diff --git a/alv-lib/vis.moon b/alv-lib/vis.moon
new file mode 100644
index 0000000..f39eb25
--- /dev/null
+++ b/alv-lib/vis.moon
@@ -0,0 +1,41 @@
+import Constant, Op, T, Input, sig, evt from require 'alv.base'
+
+bar = Constant.meta
+  meta:
+    name: 'bar'
+    summary: "visualize number as a bar."
+    examples: { '(vis/bar val [[min] max])' }
+    description: "
+Visualizes `val` as a bar with range `min, max`.
+`val` can be a `num~` or `num!`, `min` and `max` are optional `num~`.
+`min` defaults to `0` and `max` defaults to `1`."
+
+  value: class extends Op
+    pattern = (sig.num / evt.num) + -sig.num + -sig.num
+    setup: (inputs, scope) =>
+      { val, min, max } = pattern\match inputs
+      if not max
+        min, max = nil, min
+
+      @out = val.result\fork!
+
+      super
+        val: Input.hot val
+        min: Input.cold min or Constant.num 0
+        max: Input.cold max or Constant.num 1
+
+    tick: =>
+      { :val, :min, :max } = @unwrap_all!
+      delta = max - min
+      @state = (val / delta) - min
+      @out\set val
+
+    vis: =>
+      {
+        type: 'bar'
+        bar: @state
+      }
+
+{
+  :bar
+}