Highlight exact source occurrences in LSP references and goto results

1 files changed, 12 insertions, 5 deletions

diff --git a/src/lsp/lsp.zig b/src/lsp/lsp.zig
index ca19009a..9dd1da5a 100644
--- a/src/lsp/lsp.zig
+++ b/src/lsp/lsp.zig
@@ -85,10 +85,15 @@ pub fn row(out: *std.Io.Writer, path: []const u8, line: usize, col: usize, text:
 
 // Input positions are zero-based and end-exclusive; displayed spans are one-based and inclusive.
 pub fn spanRow(out: *std.Io.Writer, path: []const u8, line: usize, col: usize, end_line: usize, end_col: usize, text: []const u8) std.Io.Writer.Error!void {
-    if (end_line != line or end_col <= col) return row(out, path, line, col, text);
-    try out.print("{s}:{d}:{d}-{d} {s}\n", .{
-        path, line + 1, col + 1, end_col, std.mem.trim(u8, text, " \t\r\n"),
-    });
+    return sourceSpanRow(out, path, line, col, end_line, end_col, std.mem.trim(u8, text, " \t\r\n"));
+}
+
+/// Source bytes keep their indentation and trailing spaces so byte columns
+/// still identify the same token in the displayed snippet.
+pub fn sourceSpanRow(out: *std.Io.Writer, path: []const u8, line: usize, col: usize, end_line: usize, end_col: usize, text: []const u8) std.Io.Writer.Error!void {
+    try out.print("{s}:{d}:{d}", .{ path, line + 1, col + 1 });
+    if (end_line == line and end_col > col) try out.print("-{d}", .{end_col});
+    try out.print(" {s}\n", .{std.mem.trimEnd(u8, text, "\r\n")});
 }
 
 pub fn edit(out: *std.Io.Writer, start: usize, end: usize) std.Io.Writer.Error!void {
@@ -114,9 +119,10 @@ pub fn lineCol(source: []const u8, offset: usize) struct { line: usize, col: usi
 }
 
 test "LSP encoders report every insufficient output capacity" {
-    const cases = [_]struct { kind: enum { row, span, edit, put }, expected: []const u8 }{
+    const cases = [_]struct { kind: enum { row, span, source_span, edit, put }, expected: []const u8 }{
         .{ .kind = .row, .expected = "file:1:3 hi\n" },
         .{ .kind = .span, .expected = "file:1:3-5 hi\n" },
+        .{ .kind = .source_span, .expected = "file:1:3-5 \t hi \t\n" },
         .{ .kind = .edit, .expected = "@edit 1 3\n" },
         .{ .kind = .put, .expected = "@put 1 3 hé%20%25%0A\n" },
     };
@@ -127,6 +133,7 @@ test "LSP encoders report every insufficient output capacity" {
             const result = switch (case.kind) {
                 .row => row(&out, "file", 0, 2, " hi \n"),
                 .span => spanRow(&out, "file", 0, 2, 0, 5, " hi \n"),
+                .source_span => sourceSpanRow(&out, "file", 0, 2, 0, 5, "\t hi \t\r\n"),
                 .edit => edit(&out, 1, 3),
                 .put => put(&out, 1, 3, "hé %\n"),
             };