Aheui

Why should ASCII have all the fun? :)

Puzzlet Chung

 

Aheui(아희) is an esoteric programming language, first ever to be designed for the Hangul/Hangeul. The aim of the language is to reflect the graphical design of Hangul.

 

"Aheul"

"아희"("aheui") is an archaic term for "child" or "youngster", mainly found as an idiom "아희야"("aheui-ya", coincidently mathches with "Oh, boy!") in 15th-to-18th-century Korean poetry called Sijo. IPA notation for pronunciation of "aheui" is /ɑ.hɨj/(X-SAMPA `/A.h1j/`), or /ɑ.hɰi/(`/A.hM\i/`). However, since English language has no exact equivalent sounds of /ɨ/ and /ɰ/, it is acceptable to call it "AH-hi"/ɑ.hi/.

 

Structure of Hangul

Also known as "Korean alphabet", Hangul is truly an alphabetic system, in which each symbol represents separate phoneme, or sound.

 

아희

 

Every Hangul letter has a structure, that is, a constant is juxtaposed or surrounded by a vowel. You can recognize vowel symbols easily, as they are bar-shaped, often with an attached little rod or two. All of Hangul vowel symbols are following:

ㅏㅓㅗㅜㅡㅣ
ㅑㅕㅛㅠㅢ

ㅘㅚ　ㅐㅙ
ㅝㅟ　ㅔㅞ

Last eight complex vowels are not recognized as a feature of Aheui but as ornamental symbols; so you can ignore them.

 

Lecturing on which-symbol-stands-for-which-sound is too far from the purpose of this document. However, it is notable that similar-looking symbols represent similar sound, as all consonants can be classified into five groups:

ㄱㅋ
ㄴㄷㅌㄹ
ㅁㅂㅍ
ㅅㅈㅊ
ㅇㅎ

These consonants can also be placed under each letter, as well as on the top of the character surrounded by a vowel. The consonant on the top is called the "initial" consonant while on the bottom is the "final" consonant.

 

안흼

 

In Aheui, functions of consonants and vowels are different each other.

 

Aheui specification

WARNING: This spec is incomplete and subject to change.

 

Typical code of Aheui is a two-dimensional space of Hangul characters, where each character is a command. In there cursor is moving around to execute the character which is under the cursor, similar to the intruction pointer of Funge-98.

 

As mentioned above, consonants and vowels have different fuctions. While the consonant is the actual instruction, the vowel is to determine the cursor's next position. Precisely, when the cursor meets a character, it is engaged to the following process:

• Cursor executes the command, according to the initial consonant of the character. Final consonant might be used as an argument, if needed by the initial.
• Cursor moves, according to the vowel's direction.

There is more than one storage in Aheui. Most of them stacks, and one queue. Also the extension feature is treated as a quasi-stack where you "push" the input packets and "pop" the output packets. In any of the instructions involving a pop or two, including duplication, if a storage has less element than the instruction requires, the cursor doesn't execute the instruction but moves according to the vowel only.

 

Vowels: the Directions

Little rod attached to the bar indicates the direction of the cursor.

• ㅏ, ㅓ, ㅗ, and ㅜ moves cursor by one character right, left, top, bottom respectively.
• ㅑ, ㅕ, ㅛ, and ㅠ moves cursor by two characters right, left, top, bottom respectively.
• ㅡ, ㅣ, and  ㅢ are the "reflectors". The cursor moves back to where it had come from. While ㅢ reflects all movement of the cursor, ㅡ reflects only vertical movement of the cursor, as ㅣ does horizontal movement only. The movement which is not reflected moves in the direction it went, by the law of inertia.

 

Consonants: the Commands

The ㅇ group: null

• ㅇ, as it is shaped, is the null command, which does nothing. The cursor will immediately move as the vowel indicates.
• ㅎ is the terminate command. The cursor stops at the character and terminates the execution.

Hence "아희" itself is the code, which would be a null program.

 

The ㄴ group: arithmatic

• ㄷ is the add command. The cursor pops two element from the current storage, and pushes the sum of two values.
• ㄸ is shaped double-ㄷ, hence the multiply command. The cursor pops two element from the current storage, and pushes the product of two values.
• ㄴ is the divide command. The cursor pops two element from the current storage, divide latter value by former value(latter/former), and pushes the result.
• ㅌ is the subtract command. The cursor pops two element from the current storage, subtract former value from latter value(latter-former), and pushes the result.
• ㄹ is the modulo command. The cursor pops two element from the current storage, and pushes (latter value) modulo (former value)

The ㅁ group: storage

• ㅁ is the pop command. The cursor pops an element from the current storage. Final consonanat can be applied by case. (See below.)
• ㅂ is the push command. The cursor pushes an element to the current storage. The value to push is specified by the final consonant. (See below.)
• ㅃ, double-ㅂ, is the duplicate command. If the current storage is a stack, the cursor copies the top element. If the current storage is a queue, the cursor copies the front element.
• ㅍ is the swap command. The cursor swaps two elements .

 In ㅁ command, only ㅇ and ㅎ are recognized as a final consonant. With ㅇ, the cursor pops an element from the storage and prints it as an integer. ㅎ specifies the cursor prints the character corresponding the value as the Unicode codepoint.

That is same as in ㅂ command, where ㅇ specifies the cursor to receives an integer from user input and pushes it into the storage, and ㅎ receives a character and pushes the Unicode code point. And other final consonant of the ㅂ command stands for the value to be pushed into the storage, which is specified by the line segments that the consonant is consist of:

ㄱ	ㄴ	ㄷ	ㄹ	ㅁ	ㅂ	ㅅ	ㅈ	ㅊ	ㅋ	ㅌ	ㅍ
2	2	3	5	4	4	2	3	4	3	4

In Korean language, these "consonant clusters" are also valid as placed in the final. They are also used in Ahui  usefully for higher number, if you can remember which one is valid:

ㄲ	ㄳ	ㄵ	ㄶ	ㄺ	ㄻ	ㄼ	ㄽ	ㄾ	ㄿ	ㅀ	ㅄ	ㅆ
4	4	5	5	7	9	9	7	9	9	8	6	4

ㅂ command with no final consonant pushes zero. There is no way to push 1 explicitly, but it is possible by simple arithmatic, such as `반반나`(2/2), `밤받타`(4-3).

The ㅅ group: miscellaneous

• ㅅ is select command, where the cursor selects the storage. The final consonant specifies which storage is to be selected. (See below.)
• ㅆ is transfer commmand. The cursor pops an element from the current storage, and pushes it into the storage that the final consonant indicates.
• ㅈ is shaped like balance scales, and this is the compare command. The cursor pops two elements from the current storage. If the latter value is grater than or equal to the former value, the cursor pushes 1, otherwise 0.
• ㅊ has many forks, so it is the decide command. The cursor pops an element from the current storage. If the value is non-zero, the cursor moves as is specified by the vowel. If the value is zero, the cursor moves *opposite* from the vowel's direction.

 Storages you can specify with ㅅ and ㅆ commands are (none), ㄱ, ㄴ, ㄷ, ㄹ, ㅁ, ㅂ, ㅇ, ㅅ, ㅈ, ㅊ, ㅋ, ㅌ, ㅍ, ㅎ, ㄲ, ㄳ, ㄵ, ㄶ, ㄺ, ㄻ, ㄼ, ㄽ, ㄾ, ㄿ, ㅀ, ㅄ, and ㅆ. All are stacks except ㅇ, which is the queue, and ㅎ, which is the protocol the cursor communicate with an extension.

The default storage which is selected at the very beginning of the execusion is the (none) stack.

 

Implementation

The code of Aheui is written in UTF-8 encoding. Only Hangul syllables (from U+!AC00 to U+!D7A3) are recognized as a command; others are ignored.

 

Example

This code prints "Hello, world!"

1. 밤밣따빠밣밟따뿌
2. 빠맣파빨받밤뚜뭏
3. 돋밬탕빠맣붏두붇
4. 볻뫃박발뚷투뭏붖
5. 뫃도뫃희멓뭏뭏붘
6. 뫃봌토범더벌뿌뚜
7. 뽑뽀멓멓더벓뻐뚠
8. 뽀덩벐멓뻐덕더벅

 

Acknowledgement

I would like to thank Seong-hoon "Tokigun" Kang who helped me a lot working with the specification.

 

Links

• http://puzzlet.org/html/jsaheui.html - interpreter written in JavaScript
• http://dev.tokigun.net/esolang/ahui/ahui.py - interpreter written in Python