New helper, geiser-eval-wait, to facilitate synchronous evaluations

This should address, for instance, issue #30

1 files changed, 12 insertions, 1 deletions

diff --git a/elisp/geiser-mode.el b/elisp/geiser-mode.el
index 1e5df0b..06e6655 100644
--- a/elisp/geiser-mode.el
+++ b/elisp/geiser-mode.el
@@ -95,11 +95,22 @@ result is an error msg."
   (push-mark)
   (goto-char (point-max)))
 
+(defun geiser-eval-wait (req timeout)
+  "Use REQ, the result of computing an evaluation, to wait for its result.
+
+TIMEOUT is the number of seconds to wait for evaluation
+completion.  Functions returning a waitable REQ are
+`geiser-eval-region' and its derivatives evaluating buffers or
+individual sexps."
+  (geiser-con--wait req timeout))
+
 (defun geiser-eval-region (start end &optional and-go raw nomsg)
   "Eval the current region in the Geiser REPL.
 
 With prefix, goes to the REPL buffer afterwards (as
-`geiser-eval-region-and-go')"
+`geiser-eval-region-and-go').  The evaluation is performed
+asynchronously: this function's return value can be used to wait
+for its completion using `geiser-eval-wait'."
   (interactive "rP")
   (save-restriction
     (narrow-to-region start end)