FP Homework 3 - Revision history

Beh01 at 10:44, 31 October 2022

2022-10-31T10:44:29Z

Beh01 at 10:40, 31 October 2022

2022-10-31T10:40:38Z

Beh01 at 10:38, 31 October 2022

2022-10-31T10:38:14Z

Beh01 at 10:37, 31 October 2022

2022-10-31T10:37:33Z

Beh01 at 10:18, 31 October 2022

2022-10-31T10:18:32Z

Beh01: /* Immutable Array */

2022-10-31T10:07:18Z

Immutable Array

Beh01: Created page with "= Immutable data types = == Immutable Array == data Point = Point Int Int data Shape = Circle Point Int | Rectangle {topLeft:: Poi..."

2022-10-31T09:56:46Z

Created page with "= Immutable data types = == Immutable Array == <syntaxhighlight lang="Haskell"> data Point = Point Int Int data Shape = Circle Point Int | Rectangle {topLeft:: Poi..."

New page

= Immutable data types =
== Immutable Array ==

<syntaxhighlight lang="Haskell">
data Point = Point Int Int
data Shape = Circle Point Int
| Rectangle {topLeft:: Point, bottomRight::Point}
</syntaxhighlight>

@@ Line 29: / Line 29: @@
 </syntaxhighlight>
-Now, build an array composed from these triples. The individual triples will be used to store values and to store references. Internally, the array will be represented as a ternary tree composed from these triples. In this tree, leafs are values stored in these triples and branches are references stored in these triples.
+Now, build an array composed from these triples. The individual triples will be used to store values and to store references. Internally, the array will be represented as a ternary tree composed from these triples. In this tree, leaves are values stored in these triples and branches are references stored in these triples.
 For such immutable array create:
@@ Line 35: / Line 35: @@
 * ''Enumerator'' - a way to go trough the array and get all values.
 * ''Indexer'' - a way how to get a value defined by its ''index'' (in range 0..'''n-1''').
-* ''Set method'' - a way, ho to change a value in the array based on its index. While it is an immutable array, this method needs to return the new array that accomodated the change.
+* ''Set method'' - a way, ho to change a value in the array based on its index. While it is an immutable array, this method needs to return the new array that accommodated the change.

@@ Line 34: / Line 34: @@
 * ''Constructor'' - a way to define an array of given size '''n''' (an array to store '''n''' values).
 * ''Enumerator'' - a way to go trough the array and get all values.
-* ''Indexer'' - a way how to get and change a value defined by its ''index'' (in range 0..'''n-1''').
+* ''Indexer'' - a way how to get a value defined by its ''index'' (in range 0..'''n-1''').

@@ Line 34: / Line 34: @@
 * ''Constructor'' - a way to define an array of given size '''n''' (an array to store '''n''' values).
 * ''Enumerator'' - a way to go trough the array and get all values.
-* ''Indexer'' - a way how to get and change a value defined by its ''index''.
+* ''Indexer'' - a way how to get and change a value defined by its ''index'' (in range 0..'''n-1''').

← Older revision		Revision as of 10:37, 31 October 2022
Line 28:		Line 28:
	}		}
	</syntaxhighlight>		</syntaxhighlight>
		+
		+	Now, build an array composed from these triples. The individual triples will be used to store values and to store references. Internally, the array will be represented as a ternary tree composed from these triples. In this tree, leafs are values stored in these triples and branches are references stored in these triples.
		+
		+	For such immutable array create:
		+	* ''Constructor'' - a way to define an array of given size '''n''' (an array to store '''n''' values).
		+	* ''Enumerator'' - a way to go trough the array and get all values.
		+	* ''Indexer'' - a way how to get and change a value defined by its ''index''.

← Older revision		Revision as of 10:18, 31 October 2022
Line 1:		Line 1:
	= Immutable data types =		= Immutable data types =
−	== Immutable Array ==	+	== 1 - Immutable Array ==
		+
		+	Study materials for immutable (persistent) arrays are at: https://en.wikipedia.org/wiki/Persistent_data_structure or https://en.wikipedia.org/wiki/Persistent_array
		+
		+	Let's have a class representing a ''triple'' or triplet, where the values can be set only once at the beginning, when we are creating an instance of this class.
		+
		+	An example can be following class implemented in C#:

	<syntaxhighlight lang="csharp">		<syntaxhighlight lang="csharp">
−	~~private~~ abstract class ~~Triplet~~<A> ~~: ITriplet~~	+	abstract class Triple<A>
−	{	+	{
−	private A[] data = new A[3];	+	private readonly A[] data = new A[3];
−	public ~~Triplet~~(A left, A middle, A right)	+	public Triple(A left, A middle, A right)
−	{	+	{
−	data[0] = left;	+	data[0] = left;
−	data[1] = middle;	+	data[1] = middle;
−	data[2] = right;	+	data[2] = right;
−	}	+	}
−	public A this[int index]	+	public A this[int index]
−	{	+	{
−	get => index switch	+	get => index switch
−	{	+	{
−	>= 0 and <= 2 => this.data[index],	+	>= 0 and <= 2 => this.data[index],
−	_ => throw new IndexOutOfRangeException($"Index {index} out of range for a triplet.")	+	_ => throw new IndexOutOfRangeException($"Index {index} out of range for a triplet.")
−	};	+	};
−	}	+	}
−	}	+	}
	</syntaxhighlight>		</syntaxhighlight>

@@ Line 2: / Line 2: @@
 == Immutable Array ==
-<syntaxhighlight lang="Haskell">
+<syntaxhighlight lang="csharp">
-data Point = Point Int Int
+private abstract class Triplet<A> : ITriplet
-data Shape = Circle Point Int
-           | Rectangle {topLeft:: Point, bottomRight::Point}
+            private A[] data = new A[3];
 </syntaxhighlight>