Re: [NTG-context] TeX capacity exceeded - in Lua block - why?

On Thu, Jul 16, 2015 at 10:55 AM, Procházka Lukáš Ing. - Pontex s. r. o. < LPr@pontex.cz> wrote:

Hello,

On Thu, 16 Jul 2015 10:27:48 +0200, Hans Hagen wrote:

On 7/16/2015 10:20 AM, Procházka Lukáš Ing. - Pontex s. r. o. wrote:

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Hello,

why this code:

---- \def\GG{\ifmmode G_G\else$\GG$\fi}

because in math mode \GG expands \GG which expands \GG ....

I want to just pass G_G in math mode, so it seems to me that "\ifmmode G_G..." does the check.

The macro should write G + "lower index G" for both math and non-math scope.

And, in non math scope, the macro should just enclose itself by $...$ (or \m{...})...

And, this works well in TeX code:

---- \def\GG{\ifmmode G_G\else$\GG$\fi}

\starttext \GG $\GG$ \startitemize[][] \sym{\GG} \GG \sym{$\GG$} $\GG$ \sym{\m{\GG}} \m{\GG} \item End \stopitemize \stoptext ----

So how to rewrite the itemization into Lua?

maybe you mean:

...

\def\GG{\ifmmode G_G\else$GG$\fi}

... Could be \def\GG{\ifmmode G_G\else$G_G$\fi}, too, but why not \def\GG{\ifmmode G_G\else$\GG$\fi} (seems to me be simpler as the macro definition - which may be more complicated - appears only once)?

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\def\GG{\ifmmode G_G\else$\GG$\fi} means "define the macro \GG as G_G if mmmod is true, else as \GG " It's clear that you always are in a situation where mmod is true, then \GG is replaced with G_G but as soon as you fall into "mmod not true" then you have infinite recursion. -- luigi