Re: explicit fonts in specifier code?

Ar an deichiú lá de mí na Samhain, scríobh Ilya N. Golubev: I think adding these comments to the source code would be overkill, but I have no objection to explaining what you ask here. - The differing behaviour only occurs when the charset variable is non-nil; this check is on line 2871 of specifier.c. The charset variable can only be non-nil if the matchspec argument is of the correct format for a font specifier--that is, it must be a cons with the first element a character set and the second one of the symbols 'initial or 'final. If it is not a cons with the first element a charset or a symbol naming a charset, it remains nil; if it is such a cons, but the second element isn’t one of the desired symbols, an assertion is triggered on line 2850 of specifier.c. Otherwise, the code is functionally equivalent to the previous code; it loops through the inst_list, ignoring entries if their tag sets don’t match the device at hand, trying to instantiate using an entry if they do match, and returning an instantiator if such an instantiation is successful. No extant specifier matchspec, for any specifier type, matches the format used. There would need to be a local development of the specifier C code that happened to choose exactly the same format and the same two symbol names for the changed code to see a matchspec that doesn’t belong to a font specifier. I am as certain as I can be that this code will not change anything except font specifiers. Previous to this change, there was no way to set the font used for a face when using a given non-ASCII Mule charset. Now, such a customisation is possible, and relatively painless: (define-specifier-tag 'ipa nil (lambda (charset) (eq charset (find-charset 'ipa)))) (set-face-font 'default "-etl-fixed-medium-r-normal--24-240-72-72-c-120-muleipa-1" '(x ipa)) The way I chose to implement this used the existing specifier tag infrastructure; the only way to change the calculation of which specifier tags are relevant to a given instantiation and which are ignored is to change specifier_instance_from_inst_list. I would have preferred not to modify the general specifier code, but since faces are implemented as specifiers, and there was previously no way for specifiers to store charset information, I couldn’t think of an alternative. -- Santa Maradona, priez pour moi! _______________________________________________ XEmacs-Beta mailing list XEmacs-Beta(a)xemacs.org http://calypso.tux.org/cgi-bin/mailman/listinfo/xemacs-beta