Time for an 2014 update…

Task/Queue-Definition/R/queue-definition-2.r

@@ -1,27 +1,27 @@
 # The usual Scheme way : build a function that takes commands as parameters (it's like message passing oriented programming)
 queue <- function() {
-	v <- list()
-	f <- function(cmd, val=NULL) {
-		if(cmd == "push") {
-			v <<- c(v, val)
-			invisible()
-		} else if(cmd == "pop") {
-			if(length(v) == 0) {
-				stop("empty queue")
-			} else {
-				x <- v[[1]]
-				v[[1]] <<- NULL
-				x
-			}
-		} else if(cmd == "length") {
-			length(v)
-		} else if(cmd == "empty") {
-			length(v) == 0
-		} else {
-			stop("unknown command")
-		}
-	}
-	f
+    v <- list()
+    f <- function(cmd, val=NULL) {
+        if(cmd == "push") {
+            v <<- c(v, val)
+            invisible()
+        } else if(cmd == "pop") {
+            if(length(v) == 0) {
+                stop("empty queue")
+            } else {
+                x <- v[[1]]
+                v[[1]] <<- NULL
+                x
+            }
+        } else if(cmd == "length") {
+            length(v)
+        } else if(cmd == "empty") {
+            length(v) == 0
+        } else {
+            stop("unknown command")
+        }
+    }
+    f
 }
 
 # Create two queues