/**
* Gives string representation of a tree, parametrized by how to represent each position. It does
* a preorder traversal, giving a newline and some indentation before each node, then represents
* each node as specified. It can print a tree which is at most 100 levels deep.
*
* @param t tree to stringify
* @param pts how to stringify each position
* @throws IndexOutOfBoundsException if the tree is more then 100 levels deep
* @return the string representation of t
*/
public static String stringfor(InspectableTree t, PositionToString pts) {
if (spaces == null) {
spaces = new byte[200]; // tree can't be more than 100 levels deep
for (int i = 0; i < 200; ++i) spaces[i] = (byte) ' ';
}
// the 4 below was generated entirely at random
ByteArrayOutputStream bstr = new ByteArrayOutputStream(t.size() * 4);
DataOutputStream ostr = new DataOutputStream(bstr);
writeNodeAndChildren(t.root(), pts, ostr, t, 0, 2);
return bstr.toString();
}
/**
* Recursively dumps a byte representation of a subtree onto a stream. Used by stringfor( InspTree
* ). Publicly available in case you want to stringify a subtree and really think this way is less
* work than doing it yourself. You'll want to make sure the "spaces" static variable is
* initialized first :)
*
* @param subtreeRoot root of subtree to represent
* @param pts way to stringify each position
* @param ostream stream on which to represent the subtree
* @param t tree, so children(.) can be called
* @param indentation number of spaces to indent this level
* @param indentation_increment amount by which indentation will be increased before writing
* children
*/
public static void writeNodeAndChildren(
Position subtreeRoot,
PositionToString pts,
DataOutputStream ostream,
InspectableTree t,
int indentation,
int indentation_increment) {
try {
// indent, then write the subtreeRoot
ostream.write(spaces, 0, indentation);
ostream.writeBytes(pts.stringfor(subtreeRoot));
ostream.writeBytes("\n");
} catch (java.io.IOException e) {
System.err.println("\nAn I/O error occurred: " + e);
return;
}
PositionIterator pp = t.children(subtreeRoot);
// recur on all children
while (pp.hasNext())
writeNodeAndChildren(
pp.nextPosition(),
pts,
ostream,
t,
indentation + indentation_increment,
indentation_increment);
}