* base relationship
* synthesized relationship
* relation "names" should be nodes as well
* just triples? (x, R, y)



TextField = function(contents) {
  this.contents = contents
  this.letters = []
}
TextField.prototype.width = 30
TextField.prototype.letterAt = function(idx) { return (idx < 0 || idx >= this.contents.size) ? null : this.letters[idx] }

Letter = function(tf, idx) { this.tf = tf; this.idx = idx }
Letter.prototype.successor   = function() { this.succ == undefined ? this.succ = this.tf.letterAt(idx + 1) : this.succ }
Letter.prototype.predecessor = function() { this.pred == undefined ? this.pred = this.tf.letterAt(idx - 1) : this.pred }
Letter.prototype.toString    = function() {
  return "Letter(..." +
         this.predecessor().letter +
         "<" + this.letter() + ">" +
         this.successor.letter() +
         "...)"
}

TextField.prototype.classifyContents = function() {
  for (var idx = 0; idx < this.contents.length; idx++)
    this.letters[idx] = new Letter(this, idx)
}
TextField.prototype.print = function() {
  for (var idx = 0; idx < this.contents.length; idx++)
    Transcript.show(this.letterAt(idx))
}

tf = new TextField("this is a test")
tf.classifyContents()
tf.print()



Character.newId = (function() {
  return function() { return id++ }
})()
Character = function(tf, c) { this.tf = tf; this.theCharacter = c }
Character.prototype.width = function() { return 1 }

Word = function(tf) { this.tf = tf; this.first = null; this.last = null }
Word.prototype.width = function() {
  var c = this.first, w = 0
  while (true) {
    w = w + 1
    if (c == this.last)
      return w
    c = this.tf.successor(c)
  }
}

TextField.prototype.reclassify = function() {
  tf
}