Perlito5 - misc - minimal repl (js)

misc/pad.js

@@ -0,0 +1,43 @@
+
+// this is the algorithm for keeping the compile-time environment 
+// incrementally set environment; and keep a pad stack
+
+function print (s) { process.stdout.write(s) }
+
+var prog = [
+
+    '  var x = 3       ',
+
+    '  print( "x=" + x + "\\n")  ',
+
+    '  var y = 4;      ',
+
+    '  print( "y=" + y + "\\n")  ',
+
+    '  var z = 7;      ',
+
+    '  y++            ',
+
+    '  print( "y=" + y + "\\n")  ',
+
+    '  var k = y + 1; print( "k="+ k+ "\\n")  '
+
+];
+
+var pad;
+while (prog.length) {
+    var line = prog.shift();
+    cmd = '(function () { ' + 
+                line + '; ' + 
+                'return function (cmd) { ' + 
+                    'return( eval(cmd) ) ' + 
+                '} ' + 
+           '}())';
+    if (pad) {
+        pad = pad(cmd)
+    }
+    else {
+        pad = eval(cmd);
+    }
+}
+