[gtk-web: 2/4] Add information about Guile-GI.

[Emmanuele Bassi <ebassi src gnome org>]

commit 979959cad47d3a554159959a6364620dd40897b0
Author: Leo Prikler <leo prikler student tugraz at>
Date:   Fri Nov 6 12:21:54 2020 +0100

    Add information about Guile-GI.

 _docs/language-bindings/scheme.md | 51 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
---
diff --git a/_docs/language-bindings/scheme.md b/_docs/language-bindings/scheme.md
index c9b5d3b4..401bf89e 100644
--- a/_docs/language-bindings/scheme.md
+++ b/_docs/language-bindings/scheme.md
@@ -9,6 +9,13 @@ This list is by no means exhaustive.
 
 ## GNU Guile
 
+There are currently two actively maintained projects to provide GObject language bindings for GNU Guile.
+
+Bindings | Latest version | Guile 2.2 | Guile 3.0
+--- | :---: | :---: | :---:
+<a href="http://savannah.gnu.org/projects/g-golf";>G-Golf</a> | N/A | <i class="far fa-check-circle"></i> | 
<i class="fas fa-minus-circle"></i>
+<a href="https://github.com/spk121/guile-gi";>Guile-GI</a> | 0.3 | <i class="far fa-check-circle"></i> | <i 
class="fas fa-check-circle"></i>
+
 ### G-Golf
 
 #### About
@@ -48,3 +55,47 @@ G-Golf does not yet have a release, but development builds can be made from its
 * Savannah Project Page: [http://savannah.gnu.org/projects/g-golf](http://savannah.gnu.org/projects/g-golf)
 * G-Golf Website: [https://www.gnu.org/software/g-golf/](https://www.gnu.org/software/g-golf/)
 * G-Golf Reference Manual: 
[https://www.gnu.org/software/g-golf/learn.html](https://www.gnu.org/software/g-golf/learn.html)
+
+### Guile-GI
+
+#### About
+
+Guile-GI is a library for GNU Guile to generate a Scheme API from GObject Introspection information.
+It consists of a shared library containing glue code to interface with GObject and generate bindings,
+and Guile modules to export said bindings in a structured manner.
+
+#### Hello world
+
+```scheme
+(use-modules (gi))
+
+(use-typelibs (("Gio" "2.0") #:select (activate run))
+              ("Gtk" "3.0"))
+
+;; This is the callback we install to handle the `activate'
+;; signal that a <GApplication> may receive.
+(define (on-activation app)
+  ;; Create a <GtkApplicationWindow> for this
+  ;; <GtkApplication>, plus a button.
+  (let ((window (make <GtkApplicationWindow> #:application app))
+        (button (make <GtkButton> #:label "Hello World")))
+    ;; Register a lambda as the signal handler of the
+    ;; <GtkButton>'s `clicked' signal.
+    (connect button clicked (lambda (b) (close window)))
+    (add window button)
+    (show-all window)))
+
+;; Create a new <GtkApplication>
+(let ((app (make <GtkApplication> #:application-id "com.example.GtkApplication")))
+  ;; Register the procedure `on-activation' as the
+  ;; signal handler for the `activate' signal that the
+  ;; <GtkApplication> handles.
+  (connect app activate on-activation)
+  ;; Call application:run.
+  (run app '()))
+```
+
+#### See More
+
+* Github Project: [https://github.com/spk121/guile-gi](https://github.com/spk121/guile-gi)
+* Documentation: [https://spk121.github.io/guile-gi](https://spk121.github.io/guile-gi)
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