private static Gen <Regex <char> > DefineGen()
{
var delayedRegex = Gen.Delay(new GetRegex());
return(Gen.ChoiceRecursive(
new[]
{
from c in Gen.Unicode
select Regex <char> .Just(c),
Gen.Constant(Regex <char> .Fail),
Gen.Constant(Regex <char> .Epsilon),
},
new[]
{
from c in delayedRegex
select ~c,
from c in delayedRegex
select !c,
from l in delayedRegex
from r in delayedRegex
select l *r,
from l in delayedRegex
from r in delayedRegex
select l + r,
from l in delayedRegex
from r in delayedRegex
select l& r,
}));
}