Creating hierarchical data using closure in C #?
I am trying to create hierarchical data using closure in C #. I have a Method " Pair " that looks like this:
public static Func<string, int> Pair(int x,Func<string, int> y)
{
Func<string, int> pair =
(a) =>
{
if (a == "con") return x;
if (a == "crd") return y("con");
throw new Exception();
};
return pair;
}
Than I will create my Hierarchical data as below:
var pair = Pair(1,
Pair(2,
Pair(3,
Pair(4,null))));
which when visually presented looks like this:
I know this approach is wrong because I cannot get / print all the values stored in a pair. I cannot do something like this:
public static void Print(Func<string, int> pair)
{
if (pair("crd") == null) return;
Console.WriteLine(pair("con"));
Print(pair("crd")); //Compilation Error
}
Can someone tell me how to do this in C #.
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1 answer
The problem is that your pair's closure must return two different types of objects: int if you ask for "con", and the next closure on the line if you ask for "crd".
Here's one possible implementation:
Use a speaker so you can come back.
public static Func<string, dynamic> Pair(int x, Func<string, dynamic> y)
{
Func<string, dynamic> pair =
(a) =>
{
if (a == "con") return x;
if (a == "crd") return y;
throw new Exception();
};
return pair;
}
public static void Print(Func<string, dynamic> pair)
{
while (true)
{
var next = pair("crd");
Console.WriteLine((next == null ? "-":"+") +"> " + pair("con"));
if (next != null)
{
Console.WriteLine("|");
pair = (x) => next(x);
continue;
}
break;
}
}
Test:
var pair = Pair(1,
Pair(2,
Pair(3,
Pair(4, null))));
Print(pair);
output:
+> 1
|
+> 2
|
+> 3
|
-> 4
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