Component definitions support using Guile records

* src/system.scm: define-component
                  get-component-type

diff --git a/src/system.scm b/src/system.scm
new file mode 100644 (file)
index 0000000..b4f4870
--- /dev/null
+++ b/src/system.scm
@@ -0,0 +1,47 @@
+;;; Gacela, a GNU Guile extension for fast games development
+;;; Copyright (C) 2013 by Javier Sancho Fernandez <jsf at jsancho dot org>
+;;;
+;;; This program 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.
+;;;
+;;; This program 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/>.
+
+
+(define-module (gacela system)
+  #:use-module (srfi srfi-9))
+
+
+;;; Component definitions
+
+(define (make-symbol . args)
+  (string->symbol
+   (string-concatenate
+    (map (lambda (a) (if (symbol? a) (symbol->string a) a)) args))))
+
+(define-macro (define-component name . args)
+  `(begin
+     (use-modules (srfi srfi-9) (srfi srfi-9 gnu))
+     (define-record-type ,name
+       (,(make-symbol "make-" name) ,@args)
+       ,(make-symbol name "?")
+       ,@(map (lambda (a) (list a (make-symbol name "-" a) (make-symbol "set-" name "-" a "!"))) args))
+     (set-record-type-printer! ,name
+       (lambda (record port)
+        (format port "#<[~a]" ',name)
+        ,@(map (lambda (a) `(format port " ~a: ~a" ',a (,(make-symbol name "-" a) record))) args)
+        (format port ">")))
+     ',name))
+
+(define (get-component-type component)
+  (record-type-name (record-type-descriptor component)))
+
+(export define-component
+       get-component-type)