(according to Gemini AI):

Idris2 uses comment characters similar to Haskell:

Single-line comments: Start with -- (two hyphens). Everything from -- to the end of the line is a comment.

Multi-line comments: Enclosed by {- and -}. These can span multiple lines and can also be nested.

Additionally, Idris2 supports inline documentation comments which begin with ||| (three pipe symbols). These are parsed by the compiler and can be used to generate documentation.