Return to search.sml CVS log

Up to [Research Unix] / researchv10no / cmd / sml / doc / examples / missionaries

Annotation of researchv10no/cmd/sml/doc/examples/missionaries/search.sml, revision 1.1

1.1     ! root        1: (* state searching module *)
        !             2: 
        !             3: signature BUFFER =
        !             4: sig
        !             5:   type 'a buffer
        !             6:   exception EMPTY
        !             7:   val empty: 'a buffer
        !             8:   val get: 'a buffer -> 'a * 'a buffer
        !             9:   val put: 'a * 'a buffer -> 'a buffer
        !            10: end
        !            11: 
        !            12: signature STATE_SPACE =
        !            13: sig
        !            14:   type state
        !            15:   val goal: state -> bool
        !            16:   val moves: state -> state list
        !            17: end
        !            18: 
        !            19: signature SEARCH =
        !            20: sig
        !            21:   structure States: STATE_SPACE
        !            22:   val search: States.state -> unit
        !            23: end
        !            24: 
        !            25: functor Search(structure States: STATE_SPACE and Buffer: BUFFER): SEARCH =
        !            26: struct
        !            27: 
        !            28:   structure States = States
        !            29: 
        !            30:   open States Buffer
        !            31: 
        !            32:   fun search state = 
        !            33:       let fun try pending =
        !            34:              let val (current,pending) = get pending
        !            35:               in if goal current
        !            36:                  then (print "found"; ())
        !            37:                  else try(fold put (moves current) pending)
        !            38:              end
        !            39:        in try(put(state,empty))
        !            40:          handle EMPTY => (print "failed"; ())
        !            41:       end
        !            42: 
        !            43: end  (* Search *)

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.