2016 Update

Task/Visualize-a-tree/Elena/visualize-a-tree.elena

@@ -0,0 +1,62 @@
+#import system.
+#import system'routines.
+#import extensions.
+
+#class Node
+{
+    #field theValue.
+    #field theChildren.
+
+    #constructor new : value &children:children
+    [
+        theValue := value.
+        theChildren := children toArray.
+    ]
+
+    #constructor new : value
+        <= new:value &children:nil.
+
+    #constructor new &children:children
+        <= new:emptyLiteralValue &children:children.
+
+    #constructor new : value &child:child
+        <= new:value &children:(Array new &object:child).
+
+    #method get = theValue.
+
+    #method children = theChildren.
+}
+
+#class(extension)treeOp
+{
+    #method writeTree:node:prefix &subject:childrenProp
+    [
+        #var children := node::childrenProp get.
+        #var length := children length.
+        children zip:(RangeEnumerator new &from:1 &to:length) &eachPair:(:child:index)
+        [
+            self writeLine:prefix:"|".
+            self writeLine:prefix:"+---":(child get).
+            #var nodeLine := prefix + (index==length)iif:"    ":"|   ".
+
+            self writeTree:child:nodeLine &subject:childrenProp.
+        ].
+        ^ self.
+    ]
+
+    #method writeTree:node &subject:childrenProp
+        = self writeTree:node:"" &subject:childrenProp.
+}
+
+#symbol program =
+[
+    #var tree := Node new &children:
+                 (
+                    Node new:"a" &children:
+                    (
+                        Node new:"c" &child:(Node new:"d"),
+                        Node new:"d"
+                    ),
+                    Node new:"b").
+    console writeTree:tree &subject:%children.
+].