[NTG-context] new mp trickery / next challenge for alan and mari

10 Sep 2013

      Hi,

There's now a convenient way to pass data back from an mprun to the tex 
instance:

\starttext

\startMPcode
     passvariable("version","1.0") ;
     passvariable("number",123) ;
     passvariable("string","whatever") ;
     passvariable("point",(1,2)) ;
     passvariable("triplet",(1,2,3)) ;
     passvariable("quad",(1,2,3,4)) ;
     passvariable("boolean",false) ;
     passvariable("path",fullcircle scaled 1cm) ;

     draw fullcircle scaled 20pt ;
\stopMPcode

\ctxlua{inspect(metapost.variables)}

\ctxcommand{mprunvar("number")}
\ctxcommand{mprunvar("string")}

\stoptext

the inspect shows:

table={
  ["boolean"]=false,
  ["number"]=123,
  ["path"]={
   { 10.02177, 10.02177, 12.67969, 7.36386, 7.36386, 12.67969 },
   { 0, 14.17323, 3.75914, 14.17323, -3.75914, 14.17323 },
   { -10.02177, 10.02177, -7.36386, 12.67969, -12.67969, 7.36386 },
   { -14.17323, 0, -14.17323, 3.75914, -14.17323, -3.75914 },
   { -10.02177, -10.02177, -12.67969, -7.36386, -7.36386, -12.67969 },
   { 0, -14.17323, -3.75914, -14.17323, 3.75914, -14.17323 },
   { 10.02177, -10.02177, 7.36386, -12.67969, 12.67969, -7.36386 },
   { 14.17323, 0, 14.17323, -3.75914, 14.17323, 3.75914 },
  },
  ["point"]={ 1, 2 },
  ["quad"]={ 1, 2, 3, 4 },
  ["string"]="whatever",
  ["triplet"]={ 1, 2, 3 },
  ["version"]="1.0",
}

the mprunvar pips a value or concatination to tex

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