bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/ide/src/hover/render.rs')
-rw-r--r--crates/ide/src/hover/render.rs85
1 files changed, 84 insertions, 1 deletions
diff --git a/crates/ide/src/hover/render.rs b/crates/ide/src/hover/render.rs
index 46242b75dd..40f3406b72 100644
--- a/crates/ide/src/hover/render.rs
+++ b/crates/ide/src/hover/render.rs
@@ -1082,7 +1082,19 @@ fn render_memory_layout(
if config.niches {
if let Some(niches) = layout.niches() {
- format_to!(label, "niches = {niches}, ");
+ if niches > 1024 {
+ if niches.is_power_of_two() {
+ format_to!(label, "niches = 2{}, ", pwr2_to_exponent(niches));
+ } else if is_pwr2plus1(niches) {
+ format_to!(label, "niches = 2{} + 1, ", pwr2_to_exponent(niches - 1));
+ } else if is_pwr2minus1(niches) {
+ format_to!(label, "niches = 2{} - 1, ", pwr2_to_exponent(niches + 1));
+ } else {
+ format_to!(label, "niches = a lot, ");
+ }
+ } else {
+ format_to!(label, "niches = {niches}, ");
+ }
}
}
label.pop(); // ' '
@@ -1210,3 +1222,74 @@ fn render_dyn_compatibility(
}
}
}
+
+fn is_pwr2minus1(val: u128) -> bool {
+ val == u128::MAX || (val + 1).is_power_of_two()
+}
+
+fn is_pwr2plus1(val: u128) -> bool {
+ val != 0 && (val - 1).is_power_of_two()
+}
+
+/// Formats a power of two as an exponent of two, i.e. 16 => ⁴. Note that `num` MUST be a power
+/// of 2, or this function will panic.
+fn pwr2_to_exponent(num: u128) -> String {
+ const DIGITS: [char; 10] = ['⁰', '¹', '²', '³', '⁴', '⁵', '⁶', '⁷', '⁸', '⁹'];
+ assert_eq!(num.count_ones(), 1);
+ num.trailing_zeros()
+ .to_string()
+ .chars()
+ .map(|c| c.to_digit(10).unwrap() as usize)
+ .map(|idx| DIGITS[idx])
+ .collect::<String>()
+}
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+
+ const TESTERS: [u128; 10] = [0, 1, 2, 3, 4, 255, 256, 257, u128::MAX - 1, u128::MAX];
+
+ #[test]
+ fn test_is_pwr2minus1() {
+ const OUTCOMES: [bool; 10] =
+ [true, true, false, true, false, true, false, false, false, true];
+ for (test, expected) in TESTERS.iter().zip(OUTCOMES) {
+ let actual = is_pwr2minus1(*test);
+ assert_eq!(actual, expected, "is_pwr2minu1({test}) gave {actual}, expected {expected}");
+ }
+ }
+
+ #[test]
+ fn test_is_pwr2plus1() {
+ const OUTCOMES: [bool; 10] =
+ [false, false, true, true, false, false, false, true, false, false];
+ for (test, expected) in TESTERS.iter().zip(OUTCOMES) {
+ let actual = is_pwr2plus1(*test);
+ assert_eq!(actual, expected, "is_pwr2plus1({test}) gave {actual}, expected {expected}");
+ }
+ }
+
+ #[test]
+ fn test_pwr2_to_exponent() {
+ const TESTERS: [u128; 9] = [
+ 1,
+ 2,
+ 4,
+ 8,
+ 16,
+ 9223372036854775808,
+ 18446744073709551616,
+ 36893488147419103232,
+ 170141183460469231731687303715884105728,
+ ];
+ const OUTCOMES: [&str; 9] = ["⁰", "¹", "²", "³", "⁴", "⁶³", "⁶⁴", "⁶⁵", "¹²⁷"];
+ for (test, expected) in TESTERS.iter().zip(OUTCOMES) {
+ let actual = pwr2_to_exponent(*test);
+ assert_eq!(
+ actual, expected,
+ "pwr2_to_exponent({test}) returned {actual}, expected {expected}",
+ );
+ }
+ }
+}