From: Javier Sancho <jsf@jsancho.org>
Date: Wed, 11 Sep 2013 05:13:43 +0000 (+0200)
Subject: Making systems with macros instead functions. Now, we have define-system and make... 
X-Git-Url: https://git.jsancho.org/?a=commitdiff_plain;h=ae294fed13cd0a99c87d04ac98db272e87cb289f;p=gacela.git

Making systems with macros instead functions. Now, we have define-system and make-system.
---

diff --git a/src/examples/composing-systems.scm b/src/examples/composing-systems.scm
index feecee3..5af39c0 100644
--- a/src/examples/composing-systems.scm
+++ b/src/examples/composing-systems.scm
@@ -20,23 +20,21 @@
   #:use-module (ice-9 receive))
 
 
-(define s1
-  (make-system '(l)
-    (lambda (e)
-      (sleep 3)
-      (map
-       (lambda (e1)
-	 (set-entity-components (car e1) `(l . ,(cons 1 (cdadr e1)))))
-       e))))
+(define-system (s1 l)
+  (lambda (e)
+    (sleep 3)
+    (map
+     (lambda (e1)
+       (set-entity-components (car e1) `(l . ,(cons 1 (cdadr e1)))))
+     e)))
 
-(define s2
-  (make-system '(l)
-    (lambda (e)
-      (sleep 4)
-      (map
-       (lambda (e1)
-	 (set-entity-components (car e1) `(l . ,(cons 2 (cdadr e1)))))
-       e))))
+(define-system (s2 l)
+  (lambda (e)
+    (sleep 4)
+    (map
+     (lambda (e1)
+       (set-entity-components (car e1) `(l . ,(cons 2 (cdadr e1)))))
+     e)))
 
 (define (composing-with-join)
   (let ((entities '())
diff --git a/src/examples/making-systems.scm b/src/examples/making-systems.scm
index b3f381d..3709719 100644
--- a/src/examples/making-systems.scm
+++ b/src/examples/making-systems.scm
@@ -25,11 +25,11 @@
 (define (making-systems)
   (let ((entities '())
 	(components '()))
-    (receive (e c) (((make-system '() (lambda (e) (list (new-entity (make-a 1 2)) (new-entity (make-a 10 20))))) entities components))
+    (receive (e c) (((make-system () (lambda (e) (list (new-entity (make-a 1 2)) (new-entity (make-a 10 20))))) entities components))
 	     (set! entities e)
 	     (set! components c))
     (format #t "Two new entities with a:~%~a~%~a~%~%" entities components)
 
-    (((make-system '(a) (lambda (e) (display e) (newline) '())) entities components))))
+    (((make-system (a) (lambda (e) (display e) (newline) '())) entities components))))
 
 (export making-systems)
diff --git a/src/system.scm b/src/system.scm
index 502ccd6..2a9365b 100644
--- a/src/system.scm
+++ b/src/system.scm
@@ -175,16 +175,23 @@
 		  (lset-intersection eq? e* (find-entities-by-components c (cdr t)))))))))
 		  
 
-(define (make-system component-types system-fun)
-  (lambda (entities components)
-    (let* ((e (find-entities-by-components components component-types))
-	   (e* (map (lambda (x) (assoc x entities)) e))
-	   (e** (map (lambda (x) (cons (car x) (filter (lambda (x) (memq (car x) component-types)) (cdr x)))) e*))
-	   (res (system-fun e**)))
-      (lambda* (#:optional (entities2 #f) (components2 #f))
-	(let ((e (if (and entities2 components2) entities2 entities))
-	      (c (if (and entities2 components2) components2 components)))
-	  (modify-entities res e c))))))
+(define-macro (make-system component-types system-func)
+  `(let ((func ,system-func))
+     (lambda (entities components)
+       (let* ((e (find-entities-by-components components ',component-types))
+	      (e* (map (lambda (x) (assoc x entities)) e))
+	      (e** (map (lambda (x) (cons (car x) (filter (lambda (x) (memq (car x) ',component-types)) (cdr x)))) e*))
+	      (res (func e**)))
+	 (lambda* (#:optional (entities2 #f) (components2 #f))
+	   (let ((e (if (and entities2 components2) entities2 entities))
+		 (c (if (and entities2 components2) components2 components)))
+	     (modify-entities res e c)))))))
+
+
+(define-macro (define-system head system-func)
+  (let ((name (car head))
+	(component-types (cdr head)))
+    `(define ,name (make-system ,component-types ,system-func))))
 
 
 (define (join-systems . systems)
@@ -214,6 +221,7 @@
 
 
 (export find-entities-by-components
+	define-system
 	make-system
 	join-systems
 	threaded-systems)