Even though, following arguments are detailed only for /nta/, they are equally applicable to /ta/ as well.
Representation of /nta/ is closely related to what
is used to represent /nrra/ for writing English words like ‘Henry’ ( ) or ‘Enroll’ ( ) in Malayalam, while and is used in many new orthography fonts to represent /nta/. Typically a font places itself to be somewhere in the middle of new and old orthographies choosing only a convenient subset of conjuncts from old orthography. As an example, Mathrubhumi is the ASCII Malayalam font, which is the closest available to old orthography. Even in that, /nta/ is rendered as . So this usage is very common.
These facts give way to two quite reasonable inputting scenarios:
- There can be Malayalam keyboard layouts with specific keys for Chillu-NA(
) and RRA ( ); and nothing for /nta/.
- Even if, there is a specific method for inputting /nta/, a writer may choose to input /nta/ as Chillu-NA(
) and then RRA( ) adjacent to it.
Along with above inputting scenarios following not-so-obvious facts should also be considered:
- Since Malayalam has, just one letter to represent /ta/ and /rra/,
are essentially the same in the graphemic deep structure: Chillu-NA + RRA
- When used as /nta/,
is considered a single unit. While in /nrra/ context, it is used as having two separate components. It is evident from the reordering of left vowel signs in following examples:to be considered a fallback for stacked . , . The reordering position of the left vowel sign cannot be deduced without knowing the word context from higher text processing. This is the serious unsolved problem if we want
- Graphically ,
can be considered as Chillu-NA + subscript form of RRA. Since Chillus are not encoded (yet), as perpr#37 , the encoding for will be NA + VIRAMA + ZWJ + ZWJ + VIRAMA + RRA. This definitely is an obscure sequence!There is one more drawback to this encoding. When the font lacks subscript RRA, it rendering engine will fall back to explicit virama + full RRA form. This is not at all desired.
- Consider as a conjunct ligature of NA and RRA. This will lead to much simpler encoding NA + VIRAMA + RRA for
. This choice invalidates use ofpr#37, the fallback to level 2 can result half-form of NA (Chillu-NA) + full RRA form. This infact is the desired result. If chillu-NA is separately encoded, we would loose this fallback advantage in this method. Nevertheless, it will have the reordering problem mentioned above. That can healed to an extend by considering NA + VIRAMA + RRA as /nta/ always and NA + VIRAMA + ZWJ + RRA as /nrra/. On detecting, NA + VIRAMA + RRA, rendering engine can make sure that the left vowel sign is placed before the NA-form regardless of whether subscript-RRA is present or not. for /nta/. Now about fallback.. From
- Chillu-NA + RRA forms the conjunct (
) to represent /nta/. This conjunct is rendered only if the font has the subscript form of RRA. As per the Zero-Width-Non-Joiner’s usual meaning, Chillu-NA + RRA + ZWNJ should produce in every font. Then, as per Uniqueness rule, NA + VIRAMA + RRA should not form /nta/ conjunct. To avoid the reordering problem,on detecting Chillu-NA + RRA sequence without trailing ZWNJ, rendering engine can make sure that the left vowel sign is placed before the NA-form regardless of whether subscript-RRA is present. This option will allow Chillu-NA to be encoded.