Remove double dash from theme cmd. Update docstring. Add example.

desktop/sources/scripts/library.js

@@ -182,8 +182,8 @@ function Library (ronin) {
   }
 
   this.theme = (variable, el = document.documentElement) => {
-    // ex. styleprop('--f_high') to get css variable value
-    return getComputedStyle(el).getPropertyValue(variable)
+    // ex. (theme "f_main") -> :root { --f_main: "#fff" }
+    return getComputedStyle(el).getPropertyValue(`--${variable}`)
   }
 
   // Math

examples/theme.lisp

@@ -0,0 +1,30 @@
+((clear)
+ (def col
+   (lambda
+    (i)
+    (of
+     ((theme "f_high")
+      (theme "f_med")
+      (theme "f_low")
+      (theme "f_inv")
+      (theme "b_high")
+      (theme "b_med")
+      (theme "b_low")
+      (theme "b_inv"))
+     (mod i 8))))
+ (def rec
+   (lambda
+    (v i)
+    (if (gt v 0)
+      ((fill
+        (circle
+         (add
+          (div (of (frame) "w") 1.6)
+          (mul 1.5 v))
+         (mul 10 v)
+         (mul v (div v 5)))
+        (col i))
+       (rec
+        (sub v 3)
+        (add i 1))))))
+ (rec 40 0))