Unnamed repository; edit this file 'description' to name the repository.
checked ops
| -rw-r--r-- | lib/text-size/Cargo.toml | 2 | ||||
| -rw-r--r-- | lib/text-size/src/lib.rs | 27 |
2 files changed, 28 insertions, 1 deletions
diff --git a/lib/text-size/Cargo.toml b/lib/text-size/Cargo.toml index 6122a304dd..99fed3d728 100644 --- a/lib/text-size/Cargo.toml +++ b/lib/text-size/Cargo.toml @@ -1,6 +1,6 @@ [package] name = "text_unit" -version = "0.1.3" +version = "0.1.4" authors = ["Aleksey Kladov <[email protected]>"] description = "Newtypes for text offsets" license = "MIT OR Apache-2.0" diff --git a/lib/text-size/src/lib.rs b/lib/text-size/src/lib.rs index 00027ce69e..28b2e4d10e 100644 --- a/lib/text-size/src/lib.rs +++ b/lib/text-size/src/lib.rs @@ -28,6 +28,11 @@ impl TextUnit { } TextUnit(s.len() as u32) } + + #[inline(always)] + pub fn checked_sub(self, other: TextUnit) -> Option<TextUnit> { + self.0.checked_sub(other.0).map(TextUnit) + } } impl fmt::Debug for TextUnit { @@ -199,6 +204,17 @@ pub struct TextRange { end: TextUnit, } +impl TextRange { + #[inline(always)] + pub fn checked_sub(self, other: TextUnit) -> Option<TextRange> { + let res = TextRange::offset_len( + self.start().checked_sub(other)?, + self.len() + ); + Some(res) + } +} + impl fmt::Debug for TextRange { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { <Self as fmt::Display>::fmt(self, f) @@ -325,4 +341,15 @@ mod tests { TextRange::from_to(5.into(), 15.into()), ); } + + #[test] + fn test_checked_ops() { + let x: TextUnit = 1.into(); + assert_eq!(x.checked_sub(1.into()), Some(0.into())); + assert_eq!(x.checked_sub(2.into()), None); + + let r = TextRange::from_to(1.into(), 2.into()); + assert_eq!(r.checked_sub(1.into()), Some(TextRange::from_to(0.into(), 1.into()))); + assert_eq!(x.checked_sub(2.into()), None); + } } |