Merge 943a16beb6 into 6b12529ec3

source/niknaks/containers.d

@@ -11,6 +11,8 @@ import std.datetime.stopwatch : StopWatch, AutoStart;
 import core.thread : Thread;
 import core.sync.condition : Condition;
 import std.functional : toDelegate;
+import std.string : format;
+import niknaks.arrays : removeResize;
 
 version(unittest)
 {
@@ -597,4 +599,331 @@ unittest
 
     // Destroy the map (such that it ends the sweeper
     destroy(map);
+}
+
+public template Always(T)
+{
+    public bool Always(Tree!(T) treeNode)
+    {
+        version(unittest)
+        {
+            import std.stdio : writeln;
+            writeln("Strat for: ", treeNode);
+        }
+        return true;
+    }
+}
+
+public template Nothing(T)
+{
+    public void Nothing(Tree!(T) treeNode)
+    {
+
+    }
+}
+
+/** 
+ * The inclusion stratergy which
+ * will be called upon the tree
+ * node prior to it being visited
+ * during a dfs operation.
+ *
+ * It is a predicate to determine
+ * whether or not the tree node
+ * in concern should be recursed
+ * upon.
+ */
+public template InclusionStratergy(T)
+{
+    public alias InclusionStratergy = bool delegate(Tree!(T) item);
+}
+
+/** 
+ * This is called on a tree node
+ * as part of the first action
+ * that takes place during the
+ * visitation of said node during
+ * a dfs operation.
+ */
+public template TouchStratergy(T)
+{
+    public alias TouchStratergy = void delegate(Tree!(T) item);
+}
+
+
+
+// TODO: Technically this is a graph
+public class Tree(T)
+{
+    private T value;
+    private Tree!(T)[] children;
+
+    this(T value)
+    {
+        this.value = value;
+    }
+
+    this()
+    {
+
+    }
+
+    public void setValue(T value)
+    {
+        this.value = value;
+    }
+
+    public void appendNode(Tree!(T) node)
+    {
+        this.children ~= node;
+    }
+
+    public bool removeNode(Tree!(T) node)
+    {
+        bool found = false;
+        size_t idx;
+        for(size_t i = 0; i < this.children.length; i++)
+        {
+            found = this.children[i] == node;
+            if(found)
+            {
+                idx = i;
+                break;
+            }
+        }
+
+        if(found)
+        {
+            this.children = this.children.removeResize(idx);
+            return true;
+        }
+
+        return false;
+    }
+
+    // public T opIndex(size_t idx)
+    // {
+    //     return idx < this.children.length ? this.children[idx].getValue() : T.init;
+    // }
+
+    private static bool isTreeNodeType(E)()
+    {
+        return __traits(isSame, E, Tree!(T));
+    }
+
+    private static bool isTreeValueType(E)()
+    {
+        return __traits(isSame, E, T);
+    }
+
+    public E[] opSlice(E)()
+    if(isTreeNodeType!(E) || isTreeValueType!(E))
+    {
+        // If the children as tree nodes is requested
+        static if(isTreeNodeType!(E))
+        {
+            return this.children;
+        }
+        // If the children as values themselves is requested
+        else static if(isTreeValueType!(E))
+        {
+            T[] slice;
+            foreach(Tree!(T) tnode; this.children)
+            {
+                slice ~= tnode.value;
+            }
+            return slice;
+            // import std.algorithm.iteration : map;
+            // return map!(getValue)(this.children)[];
+        }
+    }
+
+    public T[] opSlice()
+    {
+        return opSlice!(T)();
+    }
+
+    public E opIndex(E)(size_t idx)
+    if(isTreeNodeType!(E) || isTreeValueType!(E))
+    {
+        // If the cjild as a tree node is requested
+        static if(isTreeNodeType!(E))
+        {
+            return this.children[idx];
+        }
+        // If the child as a value itself is requested
+        else static if(isTreeValueType!(E))
+        {
+            return this.children[idx].value;
+        }
+    }
+
+    public T opIndex(size_t idx)
+    {
+        return opIndex!(T)(idx);
+    }
+
+    public T[] dfs
+    (
+        InclusionStratergy!(T) strat = toDelegate(&Always!(T)),
+        TouchStratergy!(T) touch = toDelegate(&Nothing!(T))
+    )
+    {
+        version(unittest)
+        {
+            writeln("dfs entry: ", this);
+        }
+        
+        T[] collected;
+        scope(exit)
+        {
+            version(unittest)
+            {
+                writeln("leaving node ", this, " with collected ", collected);
+            }
+        }
+
+        // Touch
+        touch(this); // root[x]
+
+        foreach(Tree!(T) child; this.children) // subtree[x], 
+        {
+            if(strat(child))
+            {
+                version(unittest)
+                {
+                    writeln("dfs, strat good for child: ", child);
+                }
+
+                // Visit
+                collected ~= child.dfs(strat, touch);
+            }
+            else
+            {
+                version(unittest)
+                {
+                    writeln("dfs, strat ignored for child: ", child);
+                }
+            }
+        }
+
+        // "Visit"
+        collected ~= this.value;
+        
+        
+        return collected;
+    }
+
+    public override string toString()
+    {
+        return format("TreeNode [val: %s]", this.value);
+    }
+}
+
+
+version(unittest)
+{
+    import std.functional : toDelegate;
+    import std.stdio : writeln;
+
+    private void DebugTouch(T)(Tree!(T) node)
+    {
+        writeln("Touching tree node ", node);
+    }
+}
+
+unittest
+{
+    Tree!(string) treeOfStrings = new Tree!(string)("Top");
+
+    Tree!(string) subtree_1 = new Tree!(string)("1");
+    Tree!(string) subtree_2 = new Tree!(string)("2");
+    Tree!(string) subtree_3 = new Tree!(string)("3");
+
+    treeOfStrings.appendNode(subtree_1);
+    treeOfStrings.appendNode(subtree_2);
+    treeOfStrings.appendNode(subtree_3);
+
+
+    InclusionStratergy!(string) strat = toDelegate(&Always!(string));
+    TouchStratergy!(string) touch = toDelegate(&DebugTouch!(string));
+
+    string[] result = treeOfStrings.dfs(strat, touch);
+    writeln("dfs: ", result);
+
+    assert(result[0] == "1");
+    assert(result[1] == "2");
+    assert(result[2] == "3");
+    assert(result[3] == "Top");
+
+
+    auto i = treeOfStrings.opSlice!(Tree!(string))();
+    writeln("Siblings: ", i);
+    assert(i[0] == subtree_1);
+    assert(i[1] == subtree_2);
+    assert(i[2] == subtree_3);
+
+    auto p = treeOfStrings.opSlice!(string)();
+    writeln("Siblings (vals): ", p);
+    assert(p == treeOfStrings[]);
+
+
+    assert(treeOfStrings.removeNode(subtree_1));
+    assert(!treeOfStrings.removeNode(subtree_1));
+}
+
+public class VisitationTree(T) : Tree!(T)
+{
+    private bool visisted;    
+
+    this(T value)
+    {
+        super(value);
+    }
+
+    public T[] linearize()
+    {
+        return dfs(toDelegate(&_shouldVisit), toDelegate(&_touch));
+    }
+
+    private static bool _shouldVisit(Tree!(T) tnode)
+    {
+        VisitationTree!(T) vnode = cast(VisitationTree!(T))tnode;
+        return vnode && !vnode.isVisited();
+    }
+
+    private static void _touch(Tree!(T) tnode)
+    {
+        VisitationTree!(T) vnode = cast(VisitationTree!(T))tnode;
+        if(vnode)
+        {
+            vnode.mark();
+        }
+    }
+
+    private void mark()
+    {
+        this.visisted = true;
+    }
+    
+    private bool isVisited()
+    {
+        return this.visisted;
+    }
+}
+
+unittest
+{
+    VisitationTree!(string) root = new VisitationTree!(string)("root");
+
+    VisitationTree!(string) thing = new VisitationTree!(string)("subtree");
+    root.appendNode(thing);
+    thing.appendNode(root);
+
+    string[] linearized = root.linearize();
+    writeln(linearized);
+
+    assert(linearized[0] == "subtree");
+    assert(linearized[1] == "root");
+
 }