QDBP (Quested-Depth/Boundary-Perceived Expressions) is a tree notation framework that allows hierarchical structures to be written using either:
- explicit boundaries (ordinary S-expressions)
- explicit depth relationships (depth-annotated expressions)
or any mixture of the two.
QDBP is based on a simple observation:
Trees can be perceived in at least two fundamentally different ways:
- by seeing what belongs together (boundaries)
- by seeing where something belongs (depth)
Traditional S-expressions emphasize boundaries.
Indentation-based systems emphasize depth.
QDBP treats both as first-class parts of the same tree.
Traditional S-expression:
(package
shapes
(module
math
(fn
square
(lambda (x)
(* x x)))))
Equivalent QDBP representation:
package
.shapes
.module
..math
..fn
...square
...(lambda (x)
(* x x))
Both forms describe exactly the same tree.
The compiler processes QDBP format to output S-Expression format using API or CLI.
Resources:
QDBP is experimental.
The project explores whether boundary-oriented and depth-oriented tree representations can coexist as complementary views of the same underlying structure.
Feedback, criticism, and alternative interpretations are welcome.