Re: [NTG-context] nil from TeX to Lua

On 8/10/2021 9:23 AM, Taco Hoekwater via ntg-context wrote:

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On 9 Aug 2021, at 22:05, Aditya Mahajan via ntg-context wrote:

On Mon, 9 Aug 2021, Hans van der Meer via ntg-context wrote:

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In the TeX to Lua interface with

\def\Macro#1{\directlua{luafunction("#1")}}

the transfer from TeX to Lua is by string. However what to do at the Lua end when calling \Macro{}? As I understand it, then on the Lua side an empty argument and an empty string are indistinguishable.

On the TeX side, these are always indistinguishable (as TeX doesn’t have ’strings’) so depending on the called macro, you could just assume str == "” actually means nil?

indeed, just check for "" Hans ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl -----------------------------------------------------------------