public static Fetch <C> SelectMany <A, B, C>(this Fetch <A> self, Expression <Func <A, Fetch <B> > > bind, Expression <Func <A, B, C> > project)
{
var bindExpression = new BindProjectPair(bind, project);
var newBinds = self.CollectedExpressions.Append(bindExpression);
return(new Bind <A, B, C>(newBinds, self));
}
public static Fetch <B> Select <A, B>(this Fetch <A> self, Expression <Func <A, B> > f)
{
var isLet = LetExpression.IsLetExpression(f);
if (!isLet)
{
return(new Select <A, B>(self, f));
}
Expression <Func <A, Fetch <A> > > letBind = _ => self;
var letProject = LetExpression.RewriteLetExpression(f);
var letPair = new BindProjectPair(letBind, letProject);
return(new Bind <A, B, B>(self.CollectedExpressions.Append(letPair), self)
{
IsLet = true
});
}
