On 6/02/2015, at 7:29 am, Roman Cheplyaka
"Test.SmallCheck.Series" still states that "For data values, [depth] is the depth of nested constructor applications."
True is a single constructor, so its depth is 1. Just True is a constructor application of depth 2.
Arguably, while True *is* a constructor, it is not a *nested* constructor. To me it obviously isn't, while to you it obviously is. This kind of problem with natural language is why we need more formal specifications. In the same way, to me (Just True) *obviously* has depth (actually height) 1. It is the tree +--------+ | Just | +--------+ | v +--------+ | True | +--------+ in which the longest path from the root to a leaf contains 1 edge. Where is the second edge? For example, http://www.cs.cmu.edu/~adamchik/15-121/lectures/Trees/trees.html says - The depth of a node is the number of edges from the root to the node. - The height of a node is the number of edges from the node to the deepest leaf. - The height of a tree is [the] height of the root. These are essentially the same definitions found in http://en.wikipedia.org/wiki/Tree_(data_structure) So we don't just have a potential ambiguity (what is "nested"?) but an actual clash with standard terminology; you are defining depth tree = height tree + 1