From c59ead20f772c58b34f65e6ee8f7670165b478cc Mon Sep 17 00:00:00 2001
From: Eshel Yaron <me@eshelyaron.com>
Date: Tue, 6 Sep 2022 19:48:57 +0300
Subject: [PATCH] ENHANCED: redirect Prolog messages to Emacs message function

---
 README.org |  3 +--
 sweep.el   | 24 +++++++++++++++++++++++-
 sweep.pl   | 19 +++++++++++++++++++
 3 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/README.org b/README.org
index 2808819..e9d9cea 100644
--- a/README.org
+++ b/README.org
@@ -6,7 +6,7 @@
 #+startup:               content indent
 #+export_file_name:      sweep.texi
 #+texinfo_filename:      sweep.info
-#+texinfo_dir_category:  Prolog
+#+texinfo_dir_category:  Emacs
 #+texinfo_dir_title:     Sweep: (sweep)
 #+texinfo_dir_desc:      SWI-Prolog Embedded in Emacs
 #+texinfo_header:        @set MAINTAINERSITE @uref{https://eshelyaron.com,maintainer webpage}
@@ -330,7 +330,6 @@ This enables the many commands that the =xref= interface provides, like
 [[info:emacs#Find Identifiers][Find Identifiers in the Emacs manual]] for an overview of the available
 commands.
 
-
 * The Prolog top-level
 :PROPERTIES:
 :CUSTOM_ID: prolog-top-level
diff --git a/sweep.el b/sweep.el
index 9304d2b..1fa56f7 100644
--- a/sweep.el
+++ b/sweep.el
@@ -107,6 +107,28 @@
           (require 'sweep-module))
       (error "Sweep will not work until `sweep-module' is compiled!"))))
 
+
+(defvar sweep-messages-buffer nil)
+
+(defun sweep-setup-message-hook ()
+  (with-current-buffer
+      (setq sweep-messages-buffer (get-buffer-create "*sweep-messages*"))
+    (compilation-minor-mode))
+  (sweep-open-query "user"
+                    "sweep"
+                    "sweep_setup_message_hook"
+                    nil)
+  (let ((sol (sweep-next-solution)))
+    (sweep-close-query)
+    sol))
+
+(defun sweep-message (message)
+  (with-current-buffer sweep-messages-buffer
+    (save-excursion
+      (goto-char (point-max))
+      (insert message)
+      (newline))))
+
 (defun sweep-start-prolog-server ()
   (sweep-open-query "user"
                     "prolog_server"
@@ -122,9 +144,9 @@
          (cons (expand-file-name "bin/swipl" (file-name-directory
                                               load-file-name))
                (cons "-q" (cons "--no-signals" sweep-init-args))))
+  (sweep-setup-message-hook)
   (sweep-start-prolog-server))
 
-
 (defvar sweep-predicate-completion-collection nil)
 
 (defvar-local sweep-buffer-module "user")
diff --git a/sweep.pl b/sweep.pl
index 823f6e5..7b97502 100644
--- a/sweep.pl
+++ b/sweep.pl
@@ -33,6 +33,7 @@
 :- module(sweep,
           [ sweep_colourise_buffer/2,
             sweep_colourise_some_terms/2,
+            sweep_setup_message_hook/2,
             sweep_documentation/2,
             sweep_identifier_at_point/2,
             sweep_expand_file_name/2,
@@ -583,3 +584,21 @@ sweep_path_module(Path0, Module) :-
     atom_string(Path, Path0),
     xref_module(Path, Module0),
     atom_string(Module0, Module).
+
+
+sweep_setup_message_hook(_, _) :-
+    retractall(user:thread_message_hook(_, _, _)),
+    asserta((
+             user:thread_message_hook(Term, Kind, Lines) :-
+             sweep_message_hook(Term, Kind, Lines)
+             )).
+
+sweep_message_hook(Term, Kind, _Lines) :-
+    should_handle_message_kind(Kind),
+    !,
+    message_to_string(Term, String),
+    sweep_funcall("sweep-message", String, _).
+
+should_handle_message_kind(error).
+should_handle_message_kind(warning).
+should_handle_message_kind(debug(_)).
-- 
2.39.2