tag: 1.2
commit c667d79961f6311ddbc9c5b4d2681733660558b4
Author: João Távora <[email protected]>
Commit: João Távora <[email protected]>
Fix #125: add ability to report LSP-compliant columns
* eglot.el (eglot-current-column-function): New variable.
(eglot-lsp-abiding-column): New helper.
(eglot--pos-to-lsp-position): Use eglot-current-column-function.
(eglot-move-to-column-function): Tweak docstring.
---
eglot.el | 32 ++++++++++++++++++++++++--------
1 file changed, 24 insertions(+), 8 deletions(-)
diff --git a/eglot.el b/eglot.el
index d4a8b6f..2c0b22e 100644
--- a/eglot.el
+++ b/eglot.el
@@ -721,26 +721,42 @@ CONNECT-ARGS are passed as additional arguments to
(let ((warning-minimum-level :error))
(display-warning 'eglot (apply #'format format args) :warning)))
+(defvar eglot-current-column-function #'current-column
+ "Function to calculate the current column.
+
+This is the inverse operation of
+`eglot-move-to-column-function' (which see). It is a function of
+no arguments returning a column number. For buffers managed by
+fully LSP-compliant servers, this should be set to
+`eglot-lsp-abiding-column', and `current-column' (the default)
+for all others.")
+
+(defun eglot-lsp-abiding-column ()
+ "Calculate current COLUMN as defined by the LSP spec."
+ (/ (- (length (encode-coding-region (line-beginning-position)
+ (point) 'utf-16 t))
+ 2)
+ 2))
+
(defun eglot--pos-to-lsp-position (&optional pos)
"Convert point POS to LSP position."
(eglot--widening
(list :line (1- (line-number-at-pos pos t)) ; F!@&#$CKING OFF-BY-ONE
- :character (- (goto-char (or pos (point)))
- (line-beginning-position)))))
+ :character (progn (when pos (goto-char pos))
+ (funcall eglot-current-column-function)))))
(defvar eglot-move-to-column-function #'move-to-column
- "How to move to a column reported by the LSP server.
+ "Function to move to a column reported by the LSP server.
According to the standard, LSP column/character offsets are based
on a count of UTF-16 code units, not actual visual columns. So
when LSP says position 3 of a line containing just \"aXbc\",
where X is a multi-byte character, it actually means `b', not
-`c'. This is what the function
-`eglot-move-to-lsp-abiding-column' does.
+`c'. However, many servers don't follow the spec this closely.
-However, many servers don't follow the spec this closely, and
-thus this variable should be set to `move-to-column' in buffers
-managed by those servers.")
+For buffers managed by fully LSP-compliant servers, this should
+be set to `eglot-move-to-lsp-abiding-column', and
+`move-to-column' (the default) for all others.")
(defun eglot-move-to-lsp-abiding-column (column)
"Move to COLUMN abiding by the LSP spec."
