Sort order for Thai words

If we want to look up in a Thai dictionary or lexicon, we are faced with sorting of Thai words.

Unlike in our alphabet, which is present as a combined list of consonants and vowels, are consonants and vowels separated in the Thai script and appear in two lists.

In the first instance is sorted according to the consonants, and in the order in which we learn it:

ก ข ฃ ค ฅ ฆ ง จ ฉ ช ซ ฌ ญ ฎ ฏ ฐ ฑ ฒ ณ ด ต ถ ท ธ น บ ป ผ ฝ พ ฟ ภ ม ย ร ฤ ล ฦ ว ศ ษ ส ห ฬ อ ฮ

This list contains the two characters no longer in use (in gray) and also the characters rü and lü (red), which are vowels.

The second criterion are the vowels in the following order:

-ะ, -ั -, า, -ำ, -ิ, -ี, -,ึ -ื, -ุ, -ู, เ-, แ-, โ-, ใ-, ไ-

The last five listed here are written in front of the initial consonant of a syllable and require special consideration: They are sorted as they would stand behind the next consonant. In the case of a double initial consonant, this characters move to a place between the two character initial consonant. Remaining parts of a vowel combination stay at her place around the last initial consonant.

Sound and other diacritical marks remain completely ignored in the first step of sorting.

The first step of sorting then compares character by character from two words, until there is a difference. The first different character determines the order in the sorted list: two different consonants in according to the priority list of the consonants, a consonant has higher priority than vowels, two vowels, the list of vowels decides pursuance of the said priority. If the search for the first different character reaches the end of one word before the end of the other word, then the shorter term has the higher priority.

If the two words are absolutely the same, then (and only then) special characters are also incorporated in a second step in the following priority order:

-, -่, -้, -๊, -๋, -็, -์, -ๆ, -ฯ

Summary

1. Two given words are compared character by character from left to right up to the first difference. This difference alone decide according to the above mentioned priorities. It does no matter how many signs were previously equal, nor what follows behind. If several consonants follow each other is no need to investigate whether this is a special kind of consonant cluster, or whether they are initial or final consonant. Of vowel combinations, only the individual characters are in their current position in relation to the character that is found in the same position in the other word. The only exceptions are vowel signs in front of a consonant, which are classified as behind the consonant.

2. If found out at the comparison, that the two words are equal, any existing sound and other special characters be considered in a second step. If it proves a difference, this will decide the sort order.

3. If the shorter of two different words identical with the beginning of the longer word, the shorter one has the higher sort priority.

Special case: Compound Words

The first two words in the list below - considered in isolation - are in the right order, because the first three characters are the same and therefore the shorter term has the higher priority. Because without regarding the special character the third term in the list is identical to the first, in according to the tone rules it should be placed on the second place. However, there are dictionaries in which the following sequence is applied:

The objective of this order meaning is unmistakable. This order arises not from the above-described sorting rules. In their application would come out the following sequence:

Both sorts, however, apply to be correct. Today, probably more dictionaries are sorted by computer than by hand. A sorting algorithm that has as a result the first form is not easy to program and work only with the help of a large exception dictionary. Therefore, probably, most current dictionaries sorted by the rule and show these words in the sequence of the second list.