Re: [Dev-luatex] Uunderdelimiter & friends and mathstyles

On Mon, Apr 19, 2021 at 11:57:23PM +0200, luigi scarso wrote:

On Sun, Apr 18, 2021 at 11:15 PM Marcel Fabian Krüger wrote:

...

Hi,

I noticed some odd behavior about \U{under,over}delimiter/\Udelimiter{under,over} related to the applied mathstyles for the nucleus: Take the following example

\input luaotfload.sty \font\lmmath"Latin Modern Math:script=math,mode=base" \font\scriptlmmath"Latin Modern Math:script=math,mode=base" at 7pt \font\scriptscriptlmmath"Latin Modern Math:script=math,mode=base" at 5pt \textfont42=\lmmath \scriptfont42=\scriptlmmath \scriptscriptfont42=\scriptscriptlmmath $$ \Udelimiterunder42 "2192{\mathstyle x^L} \Udelimiterover42 "2192{\mathstyle x^L} \Uunderdelimiter42 "2192{\mathstyle x^L} \Uoverdelimiter42 "2192{\mathstyle x^L} $$ \bye

In all four situations \mathstyle shows 1, but neither of the four x^L are actually set in \mathstyle 1 (crampeddisplay):

\Udelimiterunder sets it's argument in the outer mathstyle. IMO this is the expected behavior but should be reflected in \mathstyle.

\Udelimiterover sets it's argument in the outer mathstyle. IMO it should be cramped instead.

\Uoverdelimiter sets it's argument in subscript style (cramped and one size smaller) Since there's nothing printed on top of it' argument, I think that superscript style would be better. (aka not cramped) In any case it should be reflected in \mathstyle.

\Uunderdelimiter sets it's argument in superscript style (one size smaller) Since the delimiter is printed on top of it I think that subscript style would be better (aka cramped). In any case it should be reflected in \mathstyle.

The patch at the end adapts both \mathstyle and changes the actually used styles.

hm, changing these math stuff probably breaks backward compatibility --- better if can be implemented as an option. Can you send the two patches as separated files taking the latest commit from experimental as reference ?

The two diffs are attached. Marcel