cranelift_filetests/
match_directive.rs

1/// Look for a directive in a comment string.
2/// The directive is of the form "foo:" and should follow the leading `;` in the comment:
3///
4/// ; dominates: block3 block4
5///
6/// Return the comment text following the directive.
7pub fn match_directive<'a>(comment: &'a str, directive: &str) -> Option<&'a str> {
8    assert!(
9        directive.ends_with(':'),
10        "Directive must include trailing colon"
11    );
12    let text = comment.trim_start_matches(';').trim_start();
13    text.strip_prefix(directive).map(|s| s.trim())
14}
15
16#[test]
17fn test_match_directive() {
18    assert_eq!(match_directive("; foo: bar  ", "foo:"), Some("bar"));
19    assert_eq!(match_directive(" foo:bar", "foo:"), Some("bar"));
20    assert_eq!(match_directive("foo:bar", "foo:"), Some("bar"));
21    assert_eq!(match_directive(";x foo: bar", "foo:"), None);
22    assert_eq!(match_directive(";;; foo: bar", "foo:"), Some("bar"));
23}