Effects.ObsReader

The effect for reading observable variables from a model environment.

Documentation

data ObsReader env a where

The effect for reading observed values from a model environment env

Constructors

Ask

Given the observable variable x is assigned a list of type [a] in env, attempt to retrieve its head value.

Fields

• :: Observable env x a
• => ObsVar x

  variable x to read from

• -> ObsReader env (Maybe a)

  the head value from x's list

ask :: forall env es x a. (Member (ObsReader env) es, Observable env x a) => ObsVar x -> Prog es (Maybe a)

Wrapper function for calling Ask

handleRead

Arguments

:: Env env

initial model environment

-> Prog (ObsReader env ': es) a

-> Prog es a

Handle the Ask requests of observable variables