RWST MonadRec

RWSTMonadRec.java

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package com.sm.fp.data.trans.rws;

import com.sm.fp.data.trans.RWST;
import com.sm.fp.kinds.T_;
import com.sm.fp.kinds.T__;
import com.sm.fp.kinds.T___;
import com.sm.fp.kinds.T____;
import com.sm.fp.kinds.T_____;
import com.sm.fp.typeclass1.monad.MonadRec;
import fj.F;
import fj.P;
import fj.P3;
import fj.data.Either;

/**
 *
 * @author Clinton
 */
public interface RWSTMonadRec<R,W,S,M> extends RWSTMonad<R,W,S,M>, MonadRec<T__.Mu<T___.Mu<T____.Mu<T_____.Mu<RWST.Mu,R>,W>,S>,M>> {
    
    @Override
    public MonadRec<M> m();
    
    @Override
    public default <A, B> RWST<R,W,S,M,B> tailRecM(F<A, T_<T__.Mu<T___.Mu<T____.Mu<T_____.Mu<RWST.Mu, R>, W>, S>, M>, Either<A, B>>> f, A a0) {
        return (R r, S s0) -> m().tailRecM(
            (P3<A,S,W> x) -> {
                A a = x._1();
                S s = x._2();
                W w = x._3();
                return m().fmap(
                    (P3<Either<A,B>,S,W> x2) -> {
                        Either<A,B> aOrB = x2._1();
                        S s2 = x2._2();
                        W w2 = x2._3();
                        return aOrB.bimap(
                            (A a2) -> P.p(a2, s2, wSemigroup().sum(w, w2)),
                            (B b) -> P.p(b, s2, wSemigroup().sum(w, w2))
                        );
                    },
                    RWST.narrow(f.f(a)).run(r, s)
                );
            },
            P.p(a0, s0, wMonoid().zero())
        );
    }
}