combining marks for currency characters? general combining character?

[philip chastney]

FontLab provides facilities for combining two outlines which correspond to the set operations of union, intersection and set difference

they take no discernible time to execute, and could therefore be made available at print-time, via the rendering engine

this suggests that the specification of which outlines to combine should be done within HTML (or similar)

this approach 
(i) would require no additional characters within Unicode,
(ii) would allow greater generality (the symbols you mention are often used in mathematics to denote negation, while other symbols are combined in other contexts),  
(iii) the combined outline needs to be generated before rasterization, but
(iv) the maths involved would pose no problem to the clever people who wrote the routines to rasterize outlines in the first place (though hinting would obviously no longer be possible, of course)

all the best   . . .   /phil

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On Wed, 3/8/16, Kim Slawson <kimslawson at gmail.com> wrote:

 Subject: combining marks for currency characters? general combining character?
 To: unicode at unicode.org
 Date: Wednesday, 3 August, 2016, 7:26 PM
 
 It's nice to see
 a good selection of currency symbols defined in unicode, but
 I wonder if it might be useful to add a few combining marks
 for the purpose of constructing currency symbols.
 For example, many currency symbols use single or
 double horizontal lines, vertical lines or solidi ( |, -, /,
 ||, =, // ). Having these available as combining marks would
 simplify the creation of new currency symbols, as many are
 simply overstruck letters.
 Would these be good candidates for proposed
 combining characters?
 Alternately (and I have no clue if this has been
 addressed), why not allow arbitrary combining characters?
 ZWJ does not currently work for this, but it could be
 amended to, or another joining character
 introduced.
  Kim
 Slawson
 Kernel Panic
 Consulting
 kim at slawson.org
 207-370-7401