package containers

  1. Overview
  2. Docs
package containers
Legend:
Library
Module
Module type
Parameter
Class
Class type

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

Basics

type +'a t = unit -> [ `Nil | `Node of 'a * 'a t list ]
val empty : 'a t
val is_empty : _ 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 : _ t -> int

Number of elements.

val height : _ 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 pp : 'a printer -> 'a t printer

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
OCaml

Innovation. Community. Security.

GitHub Discord Twitter Peertube RSS
About
Changelog Releases Industrial Users Academic Users Why OCaml
Ecosystem
Packages Community Events OCaml Planet Jobs
Resources
Install OCaml Get Started Platform Tools Language Manual Standard Library API Books Exercises Papers OCaml Playground Logo
Policies
Carbon Footprint Governance Privacy Code of Conduct