public static Query Append <T>(this VarList <T> initial, VarList <T> other, VarList <T> result)
{
return((initial <= VarList <T> .Empty & other <= result)
| (() =>
{
var head = new Var <T>();
var initialTail = new VarList <T>();
var resultTail = new VarList <T>();
return initial <= (head, initialTail)
& result <= (head, resultTail)
& initialTail.Append(other, resultTail);
}));
}
public static Query Chain <T>(this Func <VarList <T>, Var <T>, Query> subQuery, int repetitions, VarList <T> input, VarList <T> output = null)
{
output ??= new VarList <T>();
var queryAccumulator = Query.Success;
VarList <T> intermediary = null;
for (int index = 0; index < repetitions; index++)
{
intermediary = new VarList <T>();
var element = new Var <T>();
queryAccumulator &= subQuery(input, element) & intermediary <= input.Append(element);
}
return(intermediary <= output & queryAccumulator);
}
public static Func <VarList <T>, Query> Append <T>(this VarList <T> initial, VarList <T> tail) => result => initial.Append(tail, result);
public static Query Append <T>(this VarList <T> initial, Var <T> item, VarList <T> result)
{
return(initial.Append(VarList.Create(item), result));
}
public static Func <VarList <T>, Query> Append <T>(this VarList <T> initial, Var <T> item) => result => initial.Append(item, result);
