Comments

Katnip has six comment forms. All start with #. The character after the # picks the form.

Syntax	Span	Intent
`# text`	to end of line	Expanded
`#* text`	to end of line	Collapsed
`#! text`	to end of line	Ignored
`#< text >#`	multi-line	Expanded
`#> text <#`	multi-line	Collapsed
`#[ text ]#`	multi-line	Ignored

# an ordinary comment

#* a collapsed comment

#! this one is dropped at the lexer

#< an expanded
   multi-line comment >#

#> a collapsed
   multi-line comment <#

#[ this whole block
   is dropped at the lexer ]#

What “expanded”, “collapsed” and “ignored” mean

Scratch comments attach to blocks and can be shown open or folded in the editor. The three intents map onto that:

Expanded — meant to appear open in the Scratch editor.
Collapsed — meant to appear folded.
Ignored — never meant to leave your source. Dropped by the lexer; the parser never sees it.

Conventions in the standard library

The Katnip source uses #> for file headers — a collapsed multi-line comment at the top of a file:

#> motion.knip ~ sprite motion blocks. <#

and plain # for everything inline.