reduce with tests

lib/ajlogo.js

@@ -847,6 +847,24 @@
 
 		return [];
 	});
+
+	topcontext.setProcedure('reduce', function(name, list) {
+		var proc = this.getProcedure(name);
+		var isproc = (proc.process != null);
+		var result = list[0];
+
+		for (var k = 1; k < list.length; k++)
+		{
+			var y = list[k];
+
+			if (isproc)
+				result = proc.process(this, [result, y]);
+			else
+				result = proc.apply(this, [result, y]);
+		}
+
+		return result;
+	});
 
 	topcontext.setProcedure('thing', function(name) {
 		return this.getVariable(name);

test/test.js

@@ -220,6 +220,7 @@ assert.ok(ctx.getProcedure('ascii'));
 assert.ok(ctx.getProcedure('char'));
 assert.ok(ctx.getProcedure('filter'));
 assert.ok(ctx.getProcedure('find'));
+assert.ok(ctx.getProcedure('reduce'));
 
 result = ajlogo.compileText('make "three 3');
 (new ajlogo.CompositeExpression(result)).evaluate(ctx);
@@ -649,3 +650,7 @@ result = ajlogo.evaluateText('to oddp :x output remainder :x 2 end find "oddp [2
 assert.ok(result instanceof Array);
 assert.equal(0, result.length);
 
+// reduce
+
+assert.equal(10, ajlogo.evaluateText('reduce "sum [1 2 3 4]'));
+assert.equal(10, ajlogo.evaluateText('to mysum :x :y output sum :x :y end reduce "mysum [1 2 3 4]'));