16bit hash

["Martin v. Löwis"]

> I'm trying to create UniqueID's for dynamic postscript fonts. According
> to my resources we don't actually need to use these, but if they are
> required by a particular postscript program (perhaps to make a print run
> efficient) then the private range of these ID's is 4000000<=UID<=4999999
> ie a range of one million.
> 
> So I probably really need an 18 bit hash

I don't fully understand the example, but ISTM that "no, you don't need
a hash at all. You need a unique identification".

> The data going into the font consists of
> 
> fontBBox '[-415 -431 2014 2033]'
> charmaps ['dup (\000) 0 get /C0 put',......]
> metrics ['/C0 1251 def',.....]
> bboxes ['/C29 [0 0 512 0] def',.......]
> chardefs ['/C0 {newpath 224 418 m 234 336 ......def}',......]
> 
> ie a bunch of lists of strings which are eventually joined together and
> written out with a template to make the postscript definition.

And the UniqueID should be unique within this file, right?

Why don't you just use a serial number then?

Regards,
Martin