-- GeNeRaTeD fOr: ../../CBS/Funcons/Computations/Data flow/Storing/Simple variables/assigned.aterm
{-# LANGUAGE OverloadedStrings #-}

module Funcons.Core.Computations.DataFlow.Storing.SimpleVariables.Assigned where

import Funcons.EDSL

entities = []

types = typeEnvFromList
    []

funcons = libFromList
    [("assigned",StrictFuncon stepAssigned)]

-- |
-- /assigned(Var)/ gives the value currently assigned to the variable /Var/ .
--   If this value is /uninitialised/ , then computation /fail/ s.
assigned_ fargs = FApp "assigned" (FTuple fargs)
stepAssigned fargs =
    evalRules [] [step1,step2,step3]
    where step1 = do
            let env = emptyEnv
            env <- lifted_vsMatch fargs [VPMetaVar "Var"] env
            env <- getMutPatt "store" (VPMetaVar "Sigma") env
            env <- lifted_sideCondition (SCPatternMatch (TApp "lookup" (TTuple [TVar "Var",TVar "Sigma"])) (VPMetaVar "V")) env
            env <- lifted_sideCondition (SCNotInSort (TVar "V") (TName "uninitialised-values")) env
            putMutTerm "store" (TTuple [TVar "Sigma"]) env
            stepTermTo (TVar "V") env
          step2 = do
            let env = emptyEnv
            env <- lifted_vsMatch fargs [VPMetaVar "Var"] env
            env <- getMutPatt "store" (VPMetaVar "Sigma") env
            env <- lifted_sideCondition (SCIsInSort (TApp "lookup" (TTuple [TVar "Var",TVar "Sigma"])) (TName "uninitialised-values")) env
            putMutTerm "store" (TTuple [TVar "Sigma"]) env
            stepTo (FName "fail")
          step3 = do
            let env = emptyEnv
            env <- lifted_vsMatch fargs [VPMetaVar "Var"] env
            env <- getMutPatt "store" (VPMetaVar "Sigma") env
            env <- lifted_sideCondition (SCEquality (TApp "is-in-set" (TTuple [TVar "Var",TApp "domain" (TTuple [TVar "Sigma"])])) (TName "false")) env
            putMutTerm "store" (TTuple [TVar "Sigma"]) env
            stepTo (FName "fail")