Add readline bindings.

5 files changed, 108 insertions, 1 deletions

diff --git a/Makefile.am b/Makefile.am
index 806157f..5164774 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -48,6 +48,7 @@ SOURCES = 					\
   chickadee/array-list.scm			\
   chickadee/queue.scm				\
   chickadee/freetype.scm			\
+  chickadee/readline.scm			\
   chickadee/math.scm				\
   chickadee/math/vector.scm			\
   chickadee/math/bezier.scm			\
diff --git a/chickadee/config.scm.in b/chickadee/config.scm.in
index d540231..81b0f3e 100644
--- a/chickadee/config.scm.in
+++ b/chickadee/config.scm.in
@@ -31,6 +31,7 @@
             %libvorbisfile
             %libmpg123
             %libfreetype
+            %libreadline
             scope-datadir))
 
 ;; Try to link against multiple library possibilities, such as the
@@ -55,6 +56,7 @@
 (define %libvorbisfile '("@VORBIS_LIBDIR@/libvorbisfile" "libvorbisfile"))
 (define %libmpg123 '("@MPG123_LIBDIR@/libmpg123" "libmpg123"))
 (define %libfreetype '("@FREETYPE_LIBDIR@/libfreetype" "libfreetype"))
+(define %libreadline '("@READLINE_LIBDIR@/libreadline" "libreadline"))
 
 (define (scope-datadir file)
   "Append the Chickadee data directory to FILE."
diff --git a/chickadee/readline.scm b/chickadee/readline.scm
new file mode 100644
index 0000000..ff370e8
--- /dev/null
+++ b/chickadee/readline.scm
@@ -0,0 +1,91 @@
+;;; Chickadee Game Toolkit
+;;; Copyright © 2021 David Thompson <dthompson2@worcester.edu>
+;;;
+;;; Chickadee is free software: you can redistribute it and/or modify
+;;; it under the terms of the GNU General Public License as published
+;;; by the Free Software Foundation, either version 3 of the License,
+;;; or (at your option) any later version.
+;;;
+;;; Chickadee is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+;;; General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with this program.  If not, see
+;;; <http://www.gnu.org/licenses/>.
+
+;;; Commentary
+;;
+;; GNU readline bindings for use with the Chickadee REPL.  The
+;; guile-readline C extension is not compatible with the alternative,
+;; callback-based readline interface so here comes the FFI to the
+;; rescue.
+;;
+;;; Code:
+
+(define-module (chickadee readline)
+  #:use-module (chickadee config)
+  #:use-module (system foreign)
+  #:export (bind-readline-variable
+            install-readline-handler
+            remove-readline-handler
+            readline-read-char
+            add-readline-history))
+
+;;;
+;;; Setup
+;;;
+
+(define libreadline (dynamic-link* %libreadline))
+
+(define (readline-func return-type function-name arg-types)
+  (pointer->procedure return-type
+                      (dynamic-func function-name libreadline)
+                      arg-types))
+
+(define-syntax-rule (define-foreign name return-type func-name arg-types)
+  (define name
+    (readline-func return-type func-name arg-types)))
+
+;;;
+;;; Variables
+;;;
+
+(define-foreign rl-variable-bind void "rl_variable_bind" '(* *))
+
+(define (bind-readline-variable name value)
+  (rl-variable-bind (string->pointer name) (string->pointer value)))
+
+;;;
+;;; Callbacks
+;;;
+
+(define-foreign rl-callback-handler-install void "rl_callback_handler_install" '(* *))
+(define-foreign rl-callback-handler-remove void "rl_callback_handler_remove" '())
+(define-foreign rl-callback-read-char void "rl_callback_read_char" '())
+(define-foreign rl-callback-sigcleanup void "rl_callback_sigcleanup" '())
+
+(define (install-readline-handler prompt proc)
+  (let ((proc-ptr (procedure->pointer void
+                                      (lambda (ptr)
+                                        (proc (if (null-pointer? ptr)
+                                                  ""
+                                                  (pointer->string ptr))))
+                                      '(*))))
+    (rl-callback-handler-install (string->pointer prompt) proc-ptr)))
+
+(define (remove-readline-handler)
+  (rl-callback-handler-remove))
+
+(define (readline-read-char)
+  (rl-callback-read-char))
+
+;;;
+;;; History
+;;;
+
+(define-foreign add-history void "add_history" '(*))
+
+(define (add-readline-history line)
+  (add-history (string->pointer line)))
diff --git a/configure.ac b/configure.ac
index aa53707..699e3b6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -10,6 +10,7 @@ AC_PATH_PROG([GUILE], [guile])
 AC_CONFIG_FILES([Makefile])
 AC_CONFIG_FILES([pre-inst-env], [chmod +x pre-inst-env])
 AC_CONFIG_FILES([test-env], [chmod +x test-env])
+AC_CONFIG_FILES([scripts/chickadee], [chmod +x scripts/chickadee])
 AC_CONFIG_FILES([chickadee/config.scm])
 
 # Prepare a version of $datadir that does not contain references to
@@ -64,4 +65,14 @@ AS_IF([test "FREETYPE_LIBDIR" = "x"], [
 ])
 AC_SUBST([FREETYPE_LIBDIR])
 
+PKG_CHECK_MODULES([readline], [readline])
+PKG_CHECK_VAR([READLINE_LIBDIR], [readline], [libdir])
+AC_MSG_CHECKING([readline library path])
+AS_IF([test "x$READLINE_LIBDIR" = "x"], [
+  AC_MSG_FAILURE([Unable to identify readline lib path.])
+], [
+  AC_MSG_RESULT([$READLINE_LIBDIR])
+])
+AC_SUBST([READLINE_LIBDIR])
+
 AC_OUTPUT
diff --git a/guix.scm b/guix.scm
index 7d0bda7..5d3ddf3 100644
--- a/guix.scm
+++ b/guix.scm
@@ -48,6 +48,7 @@
              (gnu packages autotools)
              (gnu packages fontutils)
              (gnu packages pkg-config)
+             (gnu packages readline)
              (gnu packages texinfo)
              (gnu packages guile)
              (gnu packages gl)
@@ -153,7 +154,8 @@ SDL2 C shared library via the foreign function interface.")
      ("guile" ,target-guile)
      ("libvorbis" ,libvorbis)
      ("mpg123" ,mpg123)
-     ("openal" ,openal)))
+     ("openal" ,openal)
+     ("readline" ,readline)))
   (propagated-inputs
    `(("guile-opengl" ,guile3.0-opengl)
      ("guile-sdl2" ,guile-sdl2)))