More verbose and powerful system definition

* src/examples/making-systems.scm: Examples redefined

* src/system.scm: System definitions with more than one components grouping
  and without requiring a function directly

diff --git a/src/examples/making-systems.scm b/src/examples/making-systems.scm
index 0addc1bf122d1ca923bfc5b74ea3fb49cae7992b..c049a904bb2e1b3d8ea5fd9aaed4d16e1c54353a 100644 (file)
--- a/src/examples/making-systems.scm
+++ b/src/examples/making-systems.scm
@@ -22,19 +22,17 @@
 
 (define-component a x y)
 
-(define-system (s1)
-  (lambda (e)
-    (list (new-entity (make-a 1 2))
-         (new-entity (make-a 10 20)))))
-
-(define-system (s2 a)
-  (lambda (e)
-    (for-each
-     (lambda (e1)
-       (format #t "Key: ~a  Component: ~a~%" (get-key e1) (get-component 'a e1)))
-     e)
-    '()))
-
+(define-system s1 ()
+  (list (new-entity (make-a 1 2))
+       (new-entity (make-a 10 20))))
+
+(define-system s2 ((with-a (a)))
+  (for-each
+   (lambda (e)
+     (format #t "Key: ~a  Component: ~a~%" (get-key e) (get-component 'a e)))
+   with-a)
+  '())
+  
 (define (making-systems)
   (let ((entities '())
        (components '()))

diff --git a/src/system.scm b/src/system.scm
index 26e31c6f52dc66b419341a75b62d226c9c33426c..b70bfee062527580b7560bcc686d45eb32b13ab5 100644 (file)
--- a/src/system.scm
+++ b/src/system.scm
@@ -193,21 +193,30 @@
 
 (define-syntax make-system
   (syntax-rules ()
-    ((_ component-types system-func)
+    ((_ ((name (component-type ...)) ...) form ...)
      (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-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))))))))
+       (let ((name (map (lambda (x)
+                         (cons (car x)
+                               (filter (lambda (x)
+                                         (memq (car x) '(component-type ...)))
+                                       (cdr x))))
+                       (map (lambda (x)
+                              (assoc x entities))
+                            (find-entities-by-components components '(component-type ...)))))
+            ...)
+        (let ((res (begin form ...)))
+          (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-syntax define-system
   (syntax-rules ()
-    ((_ (name . component-types) system-func)
-     (define name (make-system component-types system-func)))))
+    ((_ system-name ((name (component-type ...)) ...) form ...)
+     (define system-name
+       (make-system ((name (component-type ...)) ...)
+         form
+        ...)))))
 
 (define (join-systems . systems)
   (lambda (entities components)