X-Git-Url: https://code.consxy.com/gitweb/gitweb.cgi?a=blobdiff_plain;f=src%2Fmain%2Fnvm%2Fbase.lisp;h=fc2db581e6395ae764753febb0c8d8f52e308626;hb=c75540c;hp=ba895e38456f65da034ceee932b860125cc56001;hpb=083d6c212147c2242f0513924e931bcdafd641c9;p=clnl

diff --git a/src/main/nvm/base.lisp b/src/main/nvm/base.lisp
index ba895e3..fc2db58 100644
--- a/src/main/nvm/base.lisp
+++ b/src/main/nvm/base.lisp
@@ -9,8 +9,26 @@
 (defvar *dimensions* nil)
 (defvar *topology* :torus)
 (defvar *ticks* nil)
+(defvar *breeds* nil)
 
-(defstruct turtle who color heading xcor ycor (label "") (label-color 9.9d0) (size 1d0))
+(define-condition stop nil nil)
+
+(defmacro with-stop-handler (&rest forms)
+ "MACRO WITH-STOP-HANDLER &rest FORMS => HANDLED-FORM
+
+ARGUMENTS AND VALUES:
+
+  FORMS: body to be handled
+  HANDLED-FORM: body with handling
+
+DESCRIPTION:
+
+  WITH-STOP-HANDLER is a convenience macro to handle when
+  programs issue a stop condition.  When one does, a simple
+  :stop is returned."
+ `(handler-case (progn ,@forms) (stop (s) :stop)))
+
+(defstruct turtle who color heading xcor ycor (label "") (label-color 9.9d0) (size 1d0) shape)
 (defstruct patch color xcor ycor)
 
 (defun agentset-list (agentset)
@@ -38,3 +56,12 @@
 
 (defun agent-p (o)
  (or (turtle-p o) (patch-p o)))
+
+(defun breed-p (breed)
+ (find breed *breeds* :key #'car))
+
+(defun breed-default-shape (breed)
+ (second (find breed *breeds* :key #'car)))
+
+(defsetf breed-default-shape (breed) (shape)
+ `(setf (second (find ,breed *breeds* :key #'car)) ,shape))