performance optimization of vm/lex/parse/test

test/mandelbrot.nas

@@ -1,31 +1,27 @@
 import("lib.nas");
-var yMin=-0.2;
-var yMax=0.2;
-var xMin=-1.5;
-var xMax=-1.0;
+var (yMin,yMax,xMin,xMax,line)=(-0.2,0.2,-1.5,-1.0,"");
+var (yDel,xDel)=(yMax-yMin,xMax-xMin);
 for(var yPixel=0;yPixel<24;yPixel+=1)
 {
-    var y=(yPixel/24)*(yMax-yMin)+yMin;
+    var y=(yPixel/24)*yDel+yMin;
     for(var xPixel=0;xPixel<80;xPixel+=1)
     {
-        var x=(xPixel/80)*(xMax-xMin)+xMin;
+        var x=(xPixel/80)*xDel+xMin;
         var pixel=" ";
-        var x0=x;
-        var y0=y;
+        var (x0,y0)=(x,y);
         for(var iter=0;iter<80;iter+=1)
         {
             var x1=(x0*x0)-(y0*y0)+x;
             var y1=2*x0*y0+y;
-            x0=x1;
-            y0=y1;
-            var d=(x0*x0)+(y0*y0);
-            if(d>4)
+            (x0,y0)=(x1,y1);
+            if((x0*x0)+(y0*y0)>4)
             {
-                pixel=chr(" .:;+=xX$&"[int(iter/8)]);
+                pixel=chr(" .:;+=xX$&"[iter/8]);
                 break;
             }
         }
-        print(pixel);
+        line~=pixel;
     }
-    print('\n');
-}
+    line~='\n';
+}
+print(line);