Make utf8 default, implement utf16 in terms of it

2 files changed, 22 insertions, 7 deletions

diff --git a/crates/ide_db/src/line_index.rs b/crates/ide_db/src/line_index.rs
index 490c172e3..8e9d8cca2 100644
--- a/crates/ide_db/src/line_index.rs
+++ b/crates/ide_db/src/line_index.rs
@@ -22,6 +22,14 @@ pub struct LineColUtf16 {
     pub col: u32,
 }
 
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub struct LineCol {
+    /// Zero-based
+    pub line: u32,
+    /// Zero-based utf8 offset
+    pub col: u32,
+}
+
 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
 pub(crate) struct Utf16Char {
     /// Start offset of a character inside a line, zero-based
@@ -88,18 +96,25 @@ impl LineIndex {
         LineIndex { newlines, utf16_lines }
     }
 
-    pub fn line_col(&self, offset: TextSize) -> LineColUtf16 {
+    pub fn line_col(&self, offset: TextSize) -> LineCol {
         let line = partition_point(&self.newlines, |&it| it <= offset) - 1;
         let line_start_offset = self.newlines[line];
         let col = offset - line_start_offset;
+        LineCol { line: line as u32, col: col.into() }
+    }
+
+    pub fn offset(&self, line_col: LineCol) -> TextSize {
+        self.newlines[line_col.line as usize] + TextSize::from(line_col.col)
+    }
 
-        LineColUtf16 { line: line as u32, col: self.utf8_to_utf16_col(line as u32, col) as u32 }
+    pub fn to_utf16(&self, line_col: LineCol) -> LineColUtf16 {
+        let col = self.utf8_to_utf16_col(line_col.line, line_col.col.into());
+        LineColUtf16 { line: line_col.line, col: col as u32 }
     }
 
-    pub fn offset(&self, line_col: LineColUtf16) -> TextSize {
-        //FIXME: return Result
+    pub fn to_utf8(&self, line_col: LineColUtf16) -> LineCol {
         let col = self.utf16_to_utf8_col(line_col.line, line_col.col);
-        self.newlines[line_col.line as usize] + col
+        LineCol { line: line_col.line, col: col.into() }
     }
 
     pub fn lines(&self, range: TextRange) -> impl Iterator<Item = TextRange> + '_ {
diff --git a/crates/ide_db/src/line_index/tests.rs b/crates/ide_db/src/line_index/tests.rs
index af51d7348..09f3bca62 100644
--- a/crates/ide_db/src/line_index/tests.rs
+++ b/crates/ide_db/src/line_index/tests.rs
@@ -17,14 +17,14 @@ fn test_line_index() {
 
     let index = LineIndex::new(text);
     for &(offset, line, col) in &table {
-        assert_eq!(index.line_col(offset.into()), LineColUtf16 { line, col });
+        assert_eq!(index.line_col(offset.into()), LineCol { line, col });
     }
 
     let text = "\nhello\nworld";
     let table = [(0, 0, 0), (1, 1, 0), (2, 1, 1), (6, 1, 5), (7, 2, 0)];
     let index = LineIndex::new(text);
     for &(offset, line, col) in &table {
-        assert_eq!(index.line_col(offset.into()), LineColUtf16 { line, col });
+        assert_eq!(index.line_col(offset.into()), LineCol { line, col });
     }
 }