From 021d7af55982796bf0fb55ac073bf9457bb7ba04 Mon Sep 17 00:00:00 2001
From: DahyeonWoo <wdh112139@gmail.com>
Date: Fri, 16 Sep 2022 18:23:24 +0900
Subject: [PATCH] Create `README.md` for Charset (#246)

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+# Charset
+
+## Table of Contents
+* [Charset](#Charset)
+* [ASCIICharset](#ASCIICharset)
+* [DefaultCharset](#DefaultCharset)
+* [UTFCharset](#UTFChraset)
+  * [UTF8Charset](#UTF8Charset)
+  * [UTF16Charset](#UTF16Charset)
+  * [UTF32Charset](#UTF32Charset)
+* [CharsetAutoSelector](#CharsetAutoSelector)
+* [Reference](#Reference)
+
+## Charset
+* In euphony, Follow the Charset interface.
+* Currently, Euphony library supports 5 types charsets such as ASCIICharset, DefaultCharset, UTF8Charset, UTF16Charset, UTF32Charset.
+* In case of the DefaultCharset, Hex Value Itself.
+* In case of the ASCIICharset, English & some symbols can be expressed.
+* In addition, euphony supports UTF charset.
+
+
+## ASCIICharset
+All of you are familiar with ASCII codes. When you learn C language in your freshman year of college, you must have experienced that each letter is matched with a number. 'a' is stored as 61, 'b' as 62, and 'c' as 63.
+ASCII code is stored as a total of 128 characters from 0 to 127. With only 7 bits, everything can be expressed. This means that it is stored in one byte. Everyone knows that a char type is 1 byte. ASCII is expressed with only 7 bits, so it is neatly stored in a char. All you need to know about ASCII code is this.
+
+## DefaultCharset
+Hex Value Itself.
+
+
+## UTFCharset
+UTF is a variable-width character encoding used for electronic communication. Defined by the Unicode Standard, the name is derived from Unicode (or Universal Coded Character Set) Transformation Format.
+
+#### Unicode
+An industry standard designed to consistently represent and handle all characters in the world on your computer.
+
+#### Configuration
+ISO 10646 Character Set, Character Encoding, Character Information Database, Algorithms to Handle Characters, etc.
+
+#### Code Point
+The number of tables on which characters correspond.
+
+#### Encoding
+Rules for mapping code points to binary data.
+Unicode mapping methods include UTF (Unicode Transformation Format) and UCS (Universal Coded Character Set).
+
+#### Example
+Text: "A"
+Code point: U+0041 (0000000 01000001)
+ASCII encoding: 01000001
+UTF-8 encoding: 01000001
+
+Text: "가"
+Code Point: U+AC00 (1010110 0000000)
+ASCII encoding: None
+UTF-8 encoding: 11101010 10110000 10000000
+
+
+### UTF8Charset
+* Variable length encoding (1-3 bytes)
+* Most used
+* High compatibility (superset in ASCII)
+
+### UTF16Charset
+* Fixed length encoding (2 bytes)
+* Easy to implement (same as bit representation of code points on a 2-byte basis)
+
+### UTF32Charset
+* Fixed length encoding (4 bytes)
+* Easy to compare with Unicode (it is placed in a 4-byte position)
+* Has the advantage of simplifying string processing (the size of one character is fixed to 4 bytes.)
+
+## CharsetAutoSelector
+It is a class that returns a character set that shows the shortest encoding result when a desired string is entered.
+
+## Reference
+* https://github.com/orgs/euphony-io/discussions/44
+* https://github.com/orgs/euphony-io/discussions/58
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