Module CCKTree

module CCKTree: sig .. end

Lazy Tree Structure

This structure can be used to represent trees and directed graphs (as infinite trees) in a lazy fashion. Like CCKList, it is a structural type.

type 'a sequence = ('a -> unit) -> unit

type 'a gen = unit -> 'a option

type 'a klist = unit -> [ `Cons of 'a * 'a klist | `Nil ]

type 'a printer = Buffer.t -> 'a -> unit

type 'a formatter = Format.formatter -> 'a -> unit

Basics

type 'a t = unit -> [ `Nil | `Node of 'a * 'a t list ]

val empty : 'a t

val is_empty : 'a t -> bool

val singleton : 'a -> 'a t

Tree with only one label

val node : 'a -> 'a t list -> 'a t

Build a node from a label and a list of children

val node1 : 'a -> 'a t -> 'a t

Node with one child

val node2 : 'a -> 'a t -> 'a t -> 'a t

Node with two children

val fold : ('a -> 'b -> 'a) -> 'a -> 'b t -> 'a

Fold on values in no specified order. May not terminate if the tree is infinite.

val iter : ('a -> unit) -> 'a t -> unit

val size : 'a t -> int

Number of elements

val height : 'a t -> int

Length of the longest path to empty leaves

val map : ('a -> 'b) -> 'a t -> 'b t

val (>|=) : 'a t -> ('a -> 'b) -> 'b t

val cut_depth : int -> 'a t -> 'a t

Cut the tree at the given depth, so it becomes finite.

Graph Traversals

class type ['a] pset = object .. end

Abstract Set structure

val set_of_cmp : ?cmp:('a -> 'a -> int) -> unit -> 'a pset

Build a set structure given a total ordering

val dfs : ?pset:'a pset ->
       'a t -> [ `Enter of 'a | `Exit of 'a ] klist

Depth-first traversal of the tree

val bfs : ?pset:'a pset -> 'a t -> 'a klist

Breadth-first traversal of the tree

val force : 'a t -> ([ `Nil | `Node of 'a * 'b list ] as 'b)

force t evaluates t completely and returns a regular tree structure
Since 0.13

val find : ?pset:'a pset -> ('a -> 'b option) -> 'a t -> 'b option

Look for an element that maps to Some _

Pretty-printing

Example (tree of calls for naive Fibonacci function):

  let mk_fib n =

    let rec fib' l r i =

      if i=n then r else fib' r (l+r) (i+1)

    in fib' 1 1 1;;



  let rec fib n = match n with

    | 0 | 1 -> CCKTree.singleton (`Cst n)

    | _ -> CCKTree.node2 (`Plus (mk_fib n)) (fib (n-1)) (fib (n-2));;



  let pp_node fmt = function

    | `Cst n -> Format.fprintf fmt "%d" n

    | `Plus n -> Format.fprintf fmt "%d" n;;



  Format.printf "%a@." (CCKTree.print pp_node) (fib 8);;

val print : 'a formatter -> 'a t formatter

A pretty-printer using S-expressions and boxes to render the tree. Empty nodes are not rendered; sharing is ignored.
Since 0.9

Pretty printing in the DOT (graphviz) format

module Dot: sig .. end