Current Status: In Progress
Project: Extend lttoolbox to have the power of HFST
Guidelines
- Every rule in the dictionary file must be properly compatible with the the HFST twolc engine and must not result in any kind of ambiguities.
- The xml tags must be well defined for archiphonemes and rules and must be distinct from the other existing tags in lttoolbox.
- Every rule entry should have comments adequate enough to give a brief understanding of morphophonological transformations performed by the twol compiler.
Design
- The design is still in the development stage and may need significant modifications after it is implemented on the existing language pairs.
- The design must be robust enough to support all type of rules namely:
- Phonologically conditioned deletion
- Morphologically conditioned deletion
- Phonologically conditioned symbol change
- Morphologically conditioned symbol change
- Phonologically conditioned insertion
- Morphologically conditioned insertion
Alphabets
<alphabet>аӑеёӗиоуӳыэюябвгджзклмнпрсҫтфхцчшщйьъАӐЕЁӖИОУӲЫЭЮЯБВГДЖЗКЛМНПРСҪТФХЦЧШЩЙЬЪ<ar n="A">ae</ar></alphabet>
The alphabets within the ar tags denote all the possible surface form transformations possible for the archiphoneme.
| Tag/Symbol |
Meaning
|
| ar |
archiphoneme
|
| n |
archiphoneme name
|
Sets
<sets>
<set n="Vowels">aeiou</set>
<set n="BackVow">bcdfg</set>
</sets>
| Tag/Symbol |
Meaning
|
| set |
set/group of alphabets
|
| n |
set name
|
Definitions
<sets>
<set n="Vowels">aeiou</set>
<set n="BackVow">bcdfg</set>
</sets>
| Tag/Symbol |
Meaning
|
| set |
set/group of alphabets
|
| n |
set name
|
Diacritics
<sets>
<set n="Vowels">aeiou</set>
<set n="BackVow">bcdfg</set>
</sets>
| Tag/Symbol |
Meaning
|
| set |
set/group of alphabets
|
| n |
set name
|
Rule Definitions
<sets>
<set n="Vowels">aeiou</set>
<set n="BackVow">bcdfg</set>
</sets>
| Tag/Symbol |
Meaning
|
| set |
set/group of alphabets
|
| n |
set name
|
Rules
<rules>
<rule c="Back vowel harmony for archiphoneme A">
<m><ar n="A"></m><s>a</s>
<context dir="e"><l_c><set n="BackVow"></l_c><r_c></r_c></context>
</rule>
<rule c="Only hyphen in vowel boundaries and caps">
<m><ar n="hyph?"></m><s>-</s>
<context dir="f"><l_c><set n="Vowels"></l_c><r_c></r_c></context>
</rule>
<rule c="Back vowel harmony for archiphoneme A">
<m><ar n="A"></m><s>a</s>
<context dir="b"><l_c><set n="BackVow"></l_c><r_c></r_c></context>
</rule>
<rule c="Back vowel harmony for archiphoneme A">
<m><ar n="A"></m><s>a</s>
<context dir="ne"><l_c><set n="BackVow"></l_c><r_c></r_c></context>
</rule>
</rules>
| Tag/Symbol |
Meaning
|
| rule |
twol rule
|
| c |
comment
|
| m |
morphotactic side
|
| s |
surface side
|
| context |
context for transformation
|
| dir |
direction constraint
|
| f |
a:b => _ ; If the symbol pair a:b appears it must be in context _
|
| b |
a:b <= _ ; If lexical a appears in the context _ then it must correspond to surface b
|
| e |
a:b <=> _ ; Lexical a always corresponds to b in context _
|
| ne |
a:b /<= _ ; Lexical a never corresponds to b in context _
|
| r_c |
right context
|
| l_c |
left context
|
Regular Expression Synatx
Regular expressions in the twolc syntax are handled with the help
Regular Expression Operators
| Tag/Symbol |
Meaning
|
| set |
set/group of alphabets
|
| n |
set name
|
