Re: Preventing accidental prefix match in input-method

[Joost Kremers <joostkremers@fastmail.fm>]

On Fri, Nov 23 2018, Stefan Monnier wrote:
>>> I'd like to setup an input method where I have a mapping
>>>
>>>     \b  =>  β
>>>
>>> but where I'd like it that when the user enters `\beta`
>>> the result is `\beta` rather than `βeta`.
>>>
>>> I know I can do it by adding mappings
>>>
>>>     \ba  =>  \ba
>>>     \bb  =>  \bb
>>>     \bc  =>  \bc
>>>     \bd  =>  \bd
>>>     \be  =>  \be
>>>     ...
>>>
>>> but that would blow up my input method by a factor 50.
>>> Is there a better solution?
>>
>> Would adding a mapping from `βeta` to `\beta` work?
>
> I didn't mean that only `\beta` stays untouched, sorry.
> `\big` should also stay as `\big` rather than be turned into 
> `βig`, and
> same for all other `\b<something>` where <something> is made up 
> of
> alphabetic characters.
>
> IOW I'd like to be able to say something like "\b is rewritten 
> to β but
> only if immediately followed by a word boundary".

You could always create mapping of the form "\b " (i.e., with a 
space) => β, but then you may need to add more mappings such as 
"\b.", "\b,", etc., all mapping to β. Also not ideal.

The way to deal with this, AFAICT, is to add a binding that 
effectively cancels the "special" character. For example, 
latin-9-prefix uses space for this: typing ' followed by a gives 
«á», but ' + space + a gives «'a». The TeX input method allows you 
to type backslash twice to get a single backslash.

So you could add a mapping from "\\" or "\ " to "\" and accustom 
yourself to typing "\\beta" or "\ beta" to get "\beta".


-- 
Joost Kremers
Life has its moments