Right, it's a tricky problem because (in your example) "stage1" might not be defined, so stage1 cannot appear in the definition of "check_marker".
Fortunately Neil Bawd's word ANEW does something similar: http://www.wilbaden.com/neil_bawd/tool2002.txt His original definitions are: : POSSIBLY ( "name" -- ) BL WORD FIND ?dup AND IF EXECUTE THEN ; : ANEW ( "name" -- )( Run: -- ) >IN @ POSSIBLY >IN ! MARKER ; But in AmForth it is supplied already as common/lib/anew.frt: : possibly ( "name" -- ) parse-name find-xt if execute then ; : anew ( "name" -- ) >in @ possibly >in ! marker ; On Wed, Jun 29, 2016 at 3:37 PM, Tristan Williams <h...@tjnw.co.uk> wrote: > Apologies, that should be (and is in my code) > > check_marker > > > On 29Jun16 23:23, Tristan Williams wrote: > > Hello, > > > > I would like to set a marker or execute a marker dependant upon > > whether that marker exists or not. What I have in mind is something > > like this > > > > : check_marker [defined] stage1 if stage1 else marker stage1 then ; > > > > followed by > > > > check_maker > > > > However, this does not work for me and I suspect this is because of > > a (another) gap in my understanding. > > > > At the interpreter > > > > [defined] stage1 > > > > gives 0 or -1 as I would hope but I am unable to make progress when I > > try and put it in a word. > > > > Can anyone put me out of my misery? Where am I going wrong? > > > > Kind regards and thanks, > > > > Tristan > > > > > > > > > > > ------------------------------------------------------------------------------ > > Attend Shape: An AT&T Tech Expo July 15-16. Meet us at AT&T Park in San > > Francisco, CA to explore cutting-edge tech and listen to tech luminaries > > present their vision of the future. This family event has something for > > everyone, including kids. Get more information and register today. > > http://sdm.link/attshape > > _______________________________________________ > > Amforth-devel mailing list for http://amforth.sf.net/ > > Amforth-devel@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/amforth-devel > > > > > ------------------------------------------------------------------------------ > Attend Shape: An AT&T Tech Expo July 15-16. Meet us at AT&T Park in San > Francisco, CA to explore cutting-edge tech and listen to tech luminaries > present their vision of the future. This family event has something for > everyone, including kids. Get more information and register today. > http://sdm.link/attshape > _______________________________________________ > Amforth-devel mailing list for http://amforth.sf.net/ > Amforth-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/amforth-devel > -- James Bowman http://www.excamera.com/ ------------------------------------------------------------------------------ Attend Shape: An AT&T Tech Expo July 15-16. Meet us at AT&T Park in San Francisco, CA to explore cutting-edge tech and listen to tech luminaries present their vision of the future. This family event has something for everyone, including kids. Get more information and register today. http://sdm.link/attshape _______________________________________________ Amforth-devel mailing list for http://amforth.sf.net/ Amforth-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/amforth-devel
