vendor/chalk-solve-0.80.0/src/display/utils.rs

   1 //! Render utilities which don't belong anywhere else.
   2 use std::fmt::{Display, Formatter, Result};
   3
   4 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.
  32 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 }