Add WherePred to allow predicate access in WhereClause

This also unifies parsing of WHERE_PRED bounds, now Lifetime bounds will also be
parsed using TYPE_BOUND_LIST
This commit is contained in:
Ville Penttinen 2019-03-24 19:45:11 +02:00
parent 4666138c91
commit 3f62ab8f51
5 changed files with 132 additions and 8 deletions

View file

@ -799,3 +799,70 @@ fn test_doc_comment_preserves_indents() {
let module = file.syntax().descendants().find_map(Module::cast).unwrap();
assert_eq!("doc1\n```\nfn foo() {\n // ...\n}\n```", module.doc_comment_text().unwrap());
}
#[test]
fn test_where_predicates() {
fn assert_bound(text: &str, bound: Option<&TypeBound>) {
assert_eq!(text, bound.unwrap().syntax().text().to_string());
}
let file = SourceFile::parse(
r#"
fn foo()
where
T: Clone + Copy + Debug + 'static,
'a: 'b + 'c,
Iterator::Item: 'a + Debug,
Iterator::Item: Debug + 'a,
<T as Iterator>::Item: Debug + 'a,
for<'a> F: Fn(&'a str)
{}
"#,
);
let where_clause = file.syntax().descendants().find_map(WhereClause::cast).unwrap();
let mut predicates = where_clause.predicates();
let pred = predicates.next().unwrap();
let mut bounds = pred.type_bound_list().unwrap().bounds();
assert_eq!("T", pred.type_ref().unwrap().syntax().text().to_string());
assert_bound("Clone", bounds.next());
assert_bound("Copy", bounds.next());
assert_bound("Debug", bounds.next());
assert_bound("'static", bounds.next());
let pred = predicates.next().unwrap();
let mut bounds = pred.type_bound_list().unwrap().bounds();
assert_eq!("'a", pred.lifetime().unwrap().syntax().text().to_string());
assert_bound("'b", bounds.next());
assert_bound("'c", bounds.next());
let pred = predicates.next().unwrap();
let mut bounds = pred.type_bound_list().unwrap().bounds();
assert_eq!("Iterator::Item", pred.type_ref().unwrap().syntax().text().to_string());
assert_bound("'a", bounds.next());
let pred = predicates.next().unwrap();
let mut bounds = pred.type_bound_list().unwrap().bounds();
assert_eq!("Iterator::Item", pred.type_ref().unwrap().syntax().text().to_string());
assert_bound("Debug", bounds.next());
assert_bound("'a", bounds.next());
let pred = predicates.next().unwrap();
let mut bounds = pred.type_bound_list().unwrap().bounds();
assert_eq!("<T as Iterator>::Item", pred.type_ref().unwrap().syntax().text().to_string());
assert_bound("Debug", bounds.next());
assert_bound("'a", bounds.next());
let pred = predicates.next().unwrap();
let mut bounds = pred.type_bound_list().unwrap().bounds();
assert_eq!("for<'a> F", pred.type_ref().unwrap().syntax().text().to_string());
assert_bound("Fn(&'a str)", bounds.next());
}