Backwards compatibility or sanity? help

Mark Waddingham mark at livecode.com
Sun Aug 21 10:49:41 EDT 2016


Perhaps there's a misunderstanding here...

If when you refer to rtl to mean rtl languages (such as Arabic) then there is nothing to do - rtl languages are stored in memory in logical order - ie the same way round as ltr languages. It is just the display which is changed.

If you mean doing chunk searching from high indicies to low then that would just be equivalent to reversing the order of the chars in the target string and then using the current operations on it (from what you've said about the suggested semantics).

Can you clarify your use-case?

Warmest Regards,

Mark.

Sent from my iPhone

> On 21 Aug 2016, at 15:26, hh <hh at hyperhh.de> wrote:
> 
> Ali,
> probably it's about time that you give at RTL-lesson/blog/tutorial?
> Would be very appreciated.
> 
>> Ali wrote:
>> the number of items in 'ab' is not an invariant of its read order,
>> unless you reverse the characters in the delimiter too.
>> When the item delimiter is 'aa', the items of 'baaa' are completely
>> different. What happens when the item delimiter has combining
>> characters and we're matching the precombined version?
> 
> Not reversing the LTR-delimiter to a RTL-delimiter changes the delimiter:
> Isn't it planned to introduce RTL-multichar-delimiters to solve this?
> 
>> For a more simple example of the issues here, what are the backward
>> and forward words of
>> "String without closing quote
> 
> RTL and LTR (should) have exactly the same words/truewords (seen as a counted
> set) and the same number of words/truewords. Right?
> 
> Anyway, this is not my point, because words/truewords cannot be empty
> (except as the non-existent ones 'out-of-bounds') contrary to items or lines.
> 
> My point is, that a _trailing_ LTR delimiter 'item' or 'line' that is ignored
> becomes a _leading_ RTL delimiter (delimiter also RTL), for the same string.
> 
> Thus the number of items or lines increases by one, because the LTR ignored empty
> 'item' or 'line' becomes a RTL not-ignored empty 'item' or 'line' respectively.
> And the result of "empty is among the items of" (should be an order-independent
> "element-of-check") may switch from LTR-false to RTL-true, for the same string,
> and for the same one-char-delimiter (or also reversed multichar-delimiter).
> 
> Salut, Hermann
> 
> 
> 
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