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