Это не так. С заглядываниями вперед LL(k)-парсеры могут распознавать такие же грамматки если не больше.

import std.stdio;
import std.typetuple;

// фабрика

class _abstract(AT...)
{
    T create(T)()
    {
        const i = IndexOf!(T, AT);
        static assert(i >= 0 && i < AT.length);
        return cast(T)do_create(i);
    }

    Object do_create(int i)
    {
        return null;
    }
}

template fab(AT...)
{   
    class concrete_class(CT...) : _abstract!(AT)
    {
        override Object do_create(int i)
        {   
            foreach(ii, T; CT)
            {
                if(ii == i) return cast(Object)(new T);
            }            
        }

    }
    
    _abstract!(AT) concrete(CT...)()
    {
        return new concrete_class!(CT);
    }
}


// тестовые классы и интерфейсы

// базовые интерфейсы
interface Soldier { char[] info(); };
interface Monster { char[] info(); };
interface SuperMonster { char[] info(); };


// конкретные классы
class SillySoldier : public Soldier {char[] info() {return "SillySoldier";}};
class SillyMonster : public Monster {char[] info() {return "SillyMonster";}};
class SillySuperMonster : public SuperMonster {char[] info() {return "SillySuperMonster";}};    

class BadSoldier : public Soldier {char[] info() {return "BadSoldier";}};
class BadMonster : public Monster {char[] info() {return "BadMonster";}};
class BadSuperMonster : public SuperMonster {char[] info() {return "BadSuperMonster";}};    


void print(_abstract!(Soldier, Monster, SuperMonster) f1)
{
writefln(f1);
    
auto sl = f1.create!(Soldier);
auto mn = f1.create!(Monster);
auto sp = f1.create!(SuperMonster);    
writefln(sl.info());
writefln(mn.info());
writefln(sp.info());
    
writefln();    
}

void main()
{
auto f1 =  fab!(Soldier, Monster, SuperMonster)
            .concrete!(SillySoldier, SillyMonster, SillySuperMonster);
print(f1);
    
f1 = fab!(Soldier, Monster, SuperMonster)
            .concrete!(BadSoldier, BadMonster, BadSuperMonster);
print(f1);
}

FR>>public void Linq1() {
FR>>    int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };

FR>>    var lowNums =
FR>>        from n in numbers
FR>>        where n < 5
FR>>        select n;

FR>>    Console.WriteLine("Numbers < 5:");
FR>>    foreach (var x in lowNums) {
FR>>        Console.WriteLine(x);
FR>>    }
FR>>}
FR>>

numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0]
print "Numbers < 5:"
for x in (n for n in numbers if n < 5):
  print x

VD>Nemerle рулит

VD>def numbers = array[5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
VD>WriteLine(numbers.Filter(_ < 5));
VD>

VD>def numbers = array[5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
VD>WriteLine($[x | x in numbers, x < 5]);
VD>

numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0]
print filter(lambda x: x < 5, numbers)

numbers = [5, 4, 1, 3, 9, 8, 6, 7, 2, 0]
print list(x for x in  numbers if n < 5)

VD>Nemerle рулит

VD>def numbers = array[5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
VD>WriteLine(numbers.Filter(_ < 5));
VD>

VD>def numbers = array[5, 4, 1, 3, 9, 8, 6, 7, 2, 0];
VD>WriteLine($[x | x in numbers, x < 5]);
VD>

const int numbers[] = {5, 4, 1, 3, 9, 8, 6, 7, 2, 0};
for_each(numbers, numbers + sizeof(numbers)/sizeof(int), _1 < 5 && cout<<_1<<endl);