1 files changed, 61 insertions, 0 deletions

diff --git a/crates/server/src/handlers.rs b/crates/server/src/handlers.rs
new file mode 100644
index 000000000..5ee87a4dd
--- /dev/null
+++ b/crates/server/src/handlers.rs
@@ -0,0 +1,61 @@
+use languageserver_types::{Range, Position};
+use libanalysis::World;
+use libeditor::{self, LineIndex, LineCol, TextRange, TextUnit};
+use {req, Result, FilePath};
+
+pub fn handle_syntax_tree(
+    world: World,
+    params: req::SyntaxTreeParams,
+) -> Result<String> {
+    let path = params.text_document.file_path()?;
+    let file = world.file_syntax(&path)?;
+    Ok(libeditor::syntax_tree(&file))
+}
+
+pub fn handle_extend_selection(
+    world: World,
+    params: req::ExtendSelectionParams,
+) -> Result<req::ExtendSelectionResult> {
+    let path = params.text_document.file_path()?;
+    let file = world.file_syntax(&path)?;
+    let line_index = world.file_line_index(&path)?;
+    let selections = params.selections.into_iter()
+        .map(|r| {
+            let r = to_text_range(&line_index, r);
+            let r = libeditor::extend_selection(&file, r).unwrap_or(r);
+            to_vs_range(&line_index, r)
+        })
+        .collect();
+    Ok(req::ExtendSelectionResult { selections })
+}
+
+
+fn to_text_range(line_index: &LineIndex, range: Range) -> TextRange {
+    TextRange::from_to(
+        to_text_unit(line_index, range.start),
+        to_text_unit(line_index, range.end),
+    )
+}
+
+fn to_text_unit(line_index: &LineIndex, position: Position) -> TextUnit {
+    // TODO: UTF-16
+    let line_col = LineCol {
+        line: position.line as u32,
+        col: (position.character as u32).into(),
+    };
+    line_index.offset(line_col)
+}
+
+
+fn to_vs_range(line_index: &LineIndex, range: TextRange) -> Range {
+    Range::new(
+        to_vs_position(line_index, range.start()),
+        to_vs_position(line_index, range.end()),
+    )
+}
+
+fn to_vs_position(line_index: &LineIndex, offset: TextUnit) -> Position {
+    let line_col = line_index.line_col(offset);
+    // TODO: UTF-16
+    Position::new(line_col.line as u64, u32::from(line_col.col) as u64)
+}