1 //! Render utilities which don't belong anywhere else.
2 use std::fmt::{Display, Formatter, Result};
3
as_display<F: Fn(&mut Formatter<'_>) -> Result>(f: F) -> impl Display4 pub fn as_display<F: Fn(&mut Formatter<'_>) -> Result>(f: F) -> impl Display {
5 struct ClosureDisplay<F: Fn(&mut Formatter<'_>) -> Result>(F);
6
7 impl<F: Fn(&mut Formatter<'_>) -> Result> Display for ClosureDisplay<F> {
8 fn fmt(&self, f: &mut Formatter<'_>) -> Result {
9 self.0(f)
10 }
11 }
12
13 ClosureDisplay(f)
14 }
15
16 macro_rules! write_joined_non_empty_list {
17 ($f:expr,$template:tt,$list:expr,$sep:expr) => {{
18 let mut x = $list.into_iter().peekable();
19 if x.peek().is_some() {
20 write!($f, $template, x.format($sep))
21 } else {
22 Ok(())
23 }
24 }};
25 }
26
27 /// Processes a name given by an [`Interner`][chalk_ir::interner::Interner] debug
28 /// method into something usable by the `display` module.
29 ///
30 /// This is specifically useful when implementing
31 /// [`RustIrDatabase`][crate::RustIrDatabase] `name_*` methods.
sanitize_debug_name(func: impl Fn(&mut Formatter<'_>) -> Option<Result>) -> String32 pub fn sanitize_debug_name(func: impl Fn(&mut Formatter<'_>) -> Option<Result>) -> String {
33 use std::fmt::Write;
34
35 // First, write the debug method contents to a String.
36 let mut debug_out = String::new();
37 // ignore if the result is `None`, as we can just as easily tell by looking
38 // to see if anything was written to `debug_out`.
39 write!(
40 debug_out,
41 "{}",
42 as_display(|fmt| { func(fmt).unwrap_or(Ok(())) })
43 )
44 .expect("expected writing to a String to succeed");
45 if debug_out.is_empty() {
46 return "Unknown".to_owned();
47 }
48
49 // now the actual sanitization
50 debug_out.replace(|c: char| !c.is_ascii_alphanumeric(), "_")
51 }
52