Unnamed repository; edit this file 'description' to name the repository.
| -rw-r--r-- | lib/text-size/src/range.rs | 99 |
1 files changed, 97 insertions, 2 deletions
diff --git a/lib/text-size/src/range.rs b/lib/text-size/src/range.rs index 789d300665..ebafbc7140 100644 --- a/lib/text-size/src/range.rs +++ b/lib/text-size/src/range.rs @@ -2,7 +2,7 @@ use { crate::TextSize, std::{ cmp, fmt, - ops::{Bound, Index, IndexMut, Range, RangeBounds}, + ops::{Add, AddAssign, Bound, Index, IndexMut, Range, RangeBounds, Sub, SubAssign}, }, }; @@ -11,7 +11,7 @@ use { /// # Translation from `text_unit` /// /// - `TextRange::from_to(from, to)` ⟹ `TextRange(from, to)` -/// - `TextRange::offset_len(offset, size)` ⟹ `TextRange::up_to(size).offset(offset)` +/// - `TextRange::offset_len(offset, size)` ⟹ `TextRange::up_to(size) + offset` /// - `range.start()` ⟹ `range.start()` /// - `range.end()` ⟹ `range.end()` /// - `range.len()` ⟹ `range.len()` @@ -133,6 +133,38 @@ impl TextRange { let end = cmp::max(lhs.end(), rhs.end()); TextRange(start, end) } + + /// Add an offset to this range. + /// + /// Note that this is not appropriate for changing where a `TextRange` is + /// within some string; rather, it is for changing the reference anchor + /// that the `TextRange` is measured against. + /// + /// The unchecked version (`Add::add`) will _always_ panic on overflow, + /// in contrast to primitive integers, which check in debug mode only. + #[inline] + pub fn checked_add(self, offset: TextSize) -> Option<TextRange> { + Some(TextRange { + start: self.start.checked_add(offset)?, + end: self.end.checked_add(offset)?, + }) + } + + /// Subtract an offset from this range. + /// + /// Note that this is not appropriate for changing where a `TextRange` is + /// within some string; rather, it is for changing the reference anchor + /// that the `TextRange` is measured against. + /// + /// The unchecked version (`Sub::sub`) will _always_ panic on overflow, + /// in contrast to primitive integers, which check in debug mode only. + #[inline] + pub fn checked_sub(self, offset: TextSize) -> Option<TextRange> { + Some(TextRange { + start: self.start.checked_sub(offset)?, + end: self.end.checked_sub(offset)?, + }) + } } impl Index<TextRange> for str { @@ -169,3 +201,66 @@ where r.start().into()..r.end().into() } } + +macro_rules! ops { + (impl $Op:ident for TextRange by fn $f:ident = $op:tt) => { + impl $Op<&TextSize> for TextRange { + type Output = TextRange; + #[inline] + fn $f(self, other: &TextSize) -> TextRange { + self $op *other + } + } + impl<T> $Op<T> for &TextRange + where + TextRange: $Op<T, Output=TextRange>, + { + type Output = TextRange; + #[inline] + fn $f(self, other: T) -> TextRange { + *self $op other + } + } + }; +} + +impl Add<TextSize> for TextRange { + type Output = TextRange; + #[inline] + fn add(self, offset: TextSize) -> TextRange { + self.checked_add(offset) + .expect("TextRange +offset overflowed") + } +} + +impl Sub<TextSize> for TextRange { + type Output = TextRange; + #[inline] + fn sub(self, offset: TextSize) -> TextRange { + self.checked_sub(offset) + .expect("TextRange -offset overflowed") + } +} + +ops!(impl Add for TextRange by fn add = +); +ops!(impl Sub for TextRange by fn sub = -); + +impl<A> AddAssign<A> for TextRange +where + TextRange: Add<A, Output = TextRange>, +{ + #[inline] + fn add_assign(&mut self, rhs: A) { + *self = *self + rhs + } +} + +impl<S> SubAssign<S> for TextRange +where + TextRange: Sub<S, Output = TextRange>, +{ + #[inline] + fn sub_assign(&mut self, rhs: S) { + *self = *self - rhs + } +} |