model.bend source

model.bend on the hub · documented module

import Baseimport ./protocol.bend as P# Independent abstract state: no Vec, Map, Symbols or hash dependency.type Model is Data:  Names{limit: U32, entries: List<&2,String>}def length(xs: List<&2,String>) -> U32:  match xs:    case Nil{}: 0    case Con{h,t}: U32.add(1,length(t))def search_step(index: U32, equal: Bool, later: Maybe<&2,U32>) -> Maybe<&2,U32>:  match equal:    case True{}: Some{index}    case False{}: laterdef search(xs: List<&2,String>, +name: String, +index: U32) -> Maybe<&2,U32>:  match xs:    case Nil{}: None{}    case Con{head,tail}: search_step(index,String.eq(head,name),search(tail,name,U32.add(index,1)))def append(xs: List<&2,String>, name: String) -> List<&2,String>:  match xs:    case Nil{}: Con{name,Nil{}}    case Con{h,t}: Con{h,append(t,name)}def at(xs: List<&2,String>, i: Nat) -> P.Reply:  match xs i:    case Nil{} _: P.Invalid{}    case Con{h,t} 0n: P.Name{h}    case Con{h,t} 1n+p: at(t,p)def find_reply(x: Maybe<&2,U32>) -> P.Reply:  match x:    case None{}: P.Missing{}    case Some{i}: P.Id{i}def insert_if(limit: U32, xs: List<&2,String>, name: String, n: U32, room: Bool) -> Model & P.Reply:  match room:    case True{}: (Names{limit,append(xs,name)},P.Id{n})    case False{}: (Names{limit,xs},P.Full{})def insert_found(+limit: U32, +xs: List<&2,String>, name: String, found: Maybe<&2,U32>) -> Model & P.Reply:  match found:    case Some{i}: (Names{limit,xs},P.Id{i})    case None{}: insert_if(limit,xs,name,length(xs),U32.is_lt(length(xs),limit))def step(m: Model, command: P.Command) -> Model & P.Reply:  match m:    case Names{+limit,+xs}:      match command:        case P.Intern{+name}: insert_found(limit,xs,name,search(xs,name,0))        case P.Find{name}: (Names{limit,xs},find_reply(search(xs,name,0)))        case P.Resolve{i}: (Names{limit,xs},at(xs,U32.to_nat(i)))        case P.Length{}: (Names{limit,xs},P.Number{length(xs)})        case P.Limit{}: (Names{limit,xs},P.Number{limit})def trace_next(next: Model -> List<&2,P.Observation>, pair: Model & P.Reply) -> List<&2,P.Observation>:  (m,r) = pair  match m:    case Names{+limit,+xs}:      Con{P.Observed{r,length(xs),limit,xs},next(Names{limit,xs})}def trace(commands: List<&2,P.Command>, m: Model) -> List<&2,P.Observation>:  match commands:    case Nil{}: Nil{}    case Con{c,cs}: trace_next(trace(cs),step(m,c))def run(commands: List<&2,P.Command>, limit: U32) -> List<&2,P.Observation>:  trace(commands,Names{U32.min(limit,16777216),Nil{}})