bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'lib/text-size/src/range.rs')
-rw-r--r--lib/text-size/src/range.rs99
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
+ }
+}