Data-Driven Semantic Network

Here's a super-simple version of a basic semantic network using only strings. There's not much it couldn't be extended to do. However, using only strings in this way is likely to be sub-optimal. For example, when we follow a link from one node to another, in order to go any further we have to do a second lookup, etc.

But I have to say I'm not as displeased with the look and feel of the string version as I had thought I would be, so I think this is the version I'll extend.

Standard disclaimers: as-is, no warranty or implied fitness, use at your own risk.

open System.Collections.Generic 


type Rel () =

  let store = 
    new Dictionary<string,Dictionary<string,HashSet<string>>>()
    
  member private this.TryAdd 
    ((n0,l,n1):string*string*string) = 
    let d = 
      match store.TryGetValue n0 with 
      | (true,d0) -> d0
      | (false,_) ->
          let d0 = new Dictionary<string,HashSet<string>>()
          store.Add(n0,d0)
          d0
    let h =
      match d.TryGetValue l with 
      | (true,h0) -> h0
      | (false,_) ->
          let h0 = new HashSet<string>()
          d.Add(l,h0)
          h0
    h.Add n1 |> ignore
    
  static member (+=) 
    ((r:Rel),((nln):string*string*string)) =
    r.TryAdd nln
    r
  
    
let r = Rel()
 
r += ("mammal","isA","animal") |> ignore
r += ("dog","isA","mammal") |> ignore
r += ("spot","isA","dog") += ("spot","isA","pet") |> ignore