irmin 3.5.2 · OCaml Package

Graph specifies the signature for node graphs. A node graph is a deterministic DAG, labeled by steps.

Node Graphs

type 'a t

The type for store handles.

type metadata

The type for node metadata.

val metadata_t : metadata Type.t

type contents_key

The type of user-defined contents.

val contents_key_t : contents_key Type.t

type node_key

The type for node values.

val node_key_t : node_key Type.t

type step

The type of steps. A step is used to pass from one node to another.

val step_t : step Type.t

type path

The type of store paths. A path is composed of steps.

val path_t : path Type.t

type value = [

| `Node of node_key
| `Contents of contents_key * metadata

]

The type for store values.

val value_t : value Type.t

val empty : [> Perms.write ] t -> node_key Lwt.t

The empty node.

val v : [> Perms.write ] t -> (step * value) list -> node_key Lwt.t

v t n is a new node containing n.

val list : [> Perms.read ] t -> node_key -> (step * value) list Lwt.t

list t n is the contents of the node n.

val find : [> Perms.read ] t -> node_key -> path -> value option Lwt.t

find t n p is the contents of the path p starting form n.

val add : 
  [> Perms.read_write ] t ->
  node_key ->
  path ->
  value ->
  node_key Lwt.t

add t n p v is the node x such that find t x p is Some v and it behaves the same n for other operations.

val remove : [> Perms.read_write ] t -> node_key -> path -> node_key Lwt.t

remove t n path is the node x such that find t x is None and it behhaves then same as n for other operations.

val closure : 
  [> Perms.read ] t ->
  min:node_key list ->
  max:node_key list ->
  node_key list Lwt.t

closure t min max is the unordered list of nodes n reachable from a node of max along a path which: (i) either contains no min or (ii) it ends with a min.

Note: Both min and max are subsets of n.

val iter : 
  [> Perms.read ] t ->
  min:node_key list ->
  max:node_key list ->
  ?node:(node_key -> unit Lwt.t) ->
  ?contents:(contents_key -> unit Lwt.t) ->
  ?edge:(node_key -> node_key -> unit Lwt.t) ->
  ?skip_node:(node_key -> bool Lwt.t) ->
  ?skip_contents:(contents_key -> bool Lwt.t) ->
  ?rev:bool ->
  unit ->
  unit Lwt.t

iter t min max node edge skip rev () iterates in topological order over the closure of t.

It applies the following functions while traversing the graph: node on the nodes; edge n predecessor_of_n on the directed edges; skip_node n to not include a node n, its predecessors and the outgoing edges of n and skip_contents c to not include content c.

If rev is true (the default) then the graph is traversed in the reverse order: node n is applied only after it was applied on all its predecessors; edge n p is applied after node n. Note that edge n p is applied even if p is skipped.

package irmin

Node Graphs