Comments
A comment is text to explain how some code works. Comments are ignored when running the program.
Dyon uses //
for single-line and /* */
for multi-line comments.
/* This text is inside a multi-line comment. It is ignored when running the program. */ fn main() { // Can I ask you something? println("hello?") }
A single-line comment ignores the rest of the line:
#![allow(unused)] fn main() { println("hello") // Prints `hello`. }
A multi-line comment starts with /*
and ends with */
.
#![allow(unused)] fn main() { /* testing, testing! */ println("hello") }
You can nest /* */
:
#![allow(unused)] fn main() { /* /* A comment inside a comment! */ */ }
Tips and tricks
It is more common to use //
than /* */
for documenting the code.
End a comment with a dot to make it easier to see where the line is ending:
#![allow(unused)] fn main() { // Alice opened the door // by pressing a button. }
You can use /* */
to ignore some code without removing it:
/* fn main() { println("one") } */ fn main() { println("two") }
One technique that helps making code more understandable: Organize the code in paragraphs, like in a book. Write a single-line comment for each paragraph. Separate paragraphs with an empty line.
fn main() { // Print the numbers from 1 to 10. list := sift i 10 { i + 1 } println(list) // Print the numbers from 11 to 20. list := sift i [10, 20) { i + 1 } println(list) }