I feel like I’m missing something basic. What is it?

1. I have a square.scala file:

   > cat square.scala
   /** This is the square function */
   def square(d: Double): Double = d * d
   

2. The scaladoc CLI does not accept raw *.scala files:

   > scaladoc --version
   Scaladoc version 3.6.2 -- Copyright 2002-2024, LAMP/EPFL
   
   > scaladoc square.scala
   scaladoc supports only .tasty and .jar files,
   following files will be ignored: square.scala
   

3. I can compile it into a JAR file:

   > scalac --version
   Scala compiler version 3.6.2 -- Copyright 2002-2024, LAMP/EPFL
   
   > scalac square.scala -d square.jar
   
   > jar tf square.jar
   META-INF/MANIFEST.MF
   square$package$.class
   square$package.class
   square$package.tasty
   

4. And then try to generate the scaladocs:

   > mkdir output
   
   > scaladoc square.jar -d output
   
   > ls output
   favicon.ico  fonts  hljs  images  scaladoc.version  scripts  styles  webfonts
   

   Notice, I get a folder with webpage-like stuff… but nothing about my square function. I expected some HTML listing my square function and my comment.

What do I not understand?