Is it possible to create MakeBoxesStop wrapper?

Question

It is known that output expressions are passed through MakeBoxes to turn the graphics expressions into the box language which the front end uses to represent graphics (when $Output has default option FormatType->StandardForm). For example, if we evaluate:

HoldComplete[Graphics[Disk[]]]

we get a disk wrapped by HoldComplete:

screenshot

This is because HoldComplete does not stop MakeBoxes from converting its contents to typeset expression:

In[4]:= MakeBoxes@HoldComplete[Graphics[Disk[]]]
Out[4]= RowBox[{"HoldComplete", "[", GraphicsBox[DiskBox[{0, 0}]], "]"}]

So my question is: is it possible to make some additional definitions to MakeBoxes such that wrapping any expression with head MakeBoxesStop will prevent MakeBoxes from converting this expression to typeset form? In this case the expression should look in output as any other expression with no rules associated with symbols in it; in the above case:

screenshot

P.S. Please do not suggest to use InputForm since I am not satisfied with its default behavior.

As I mentioned several times in our past conversations, the phrase HoldComplete does not stop MakeBoxes... is confusing. HoldComplete matters at evaluation stage, and for the purposes of rendering (conversion to boxes) is just a normal wrapper. I don't understand why you mentioned it here at all. What matters for the rendering/FE is the resulting box form of an expression, and this is completely separate topic from evaluation happening in the kernel. — Leonid Shifrin
@Leonnid @Alexey - the comment about 'rendering in the FE vs. what's happening in the kernel' reminded me of this reply to a MathGroup post by John Fultz. Would forcing legacy graphics rendering help? (probably a dumb suggestion, but thought I'd share) — telefunkenvf14
@telefunkenvf14 I am the wrong person to ask about this. But IMO sending the expression in the box form to the FE even when it is graphics is cleaner than sending an image, so I would not force the legacy graphics rendering unless really necessary. — Leonid Shifrin
Strongly related: Prevent graphics render inside held expression. — Alexey Popkov

Leonid Shifrin Leonid Shifrin · Accepted Answer · 2011-06-30T12:33:43

This function seems to do it:

Clear[MakeBoxesStop];
MakeBoxesStop /: MakeBoxes[MakeBoxesStop[expr_], form_] :=
  Module[{heldHeads = 
     Join @@ Cases[expr,s_Symbol[___] :> HoldComplete[s], {0, Infinity}, 
      Heads -> True], 
    modified, direct,  tempContext = ToString[Unique[]] <> "`"},
   Block[{$ContextPath = $ContextPath, $Packages  = $Packages},
     BeginPackage[tempContext];
       modified = 
        Join @@ Map[
          Function[head,
             ToExpression[ToLowerCase[ToString[Unevaluated[head]]],InputForm, HoldComplete],     
             HoldAllComplete], 
          heldHeads];
     EndPackage[];
     With[{newexpr = 
       expr /. (List @@ Thread[HoldPattern /@ heldHeads -> modified, HoldComplete])},
       With[{result = 
        MakeBoxes[newexpr, form] /. 
           Thread[Rule @@ 
              Map[List @@ 
                 Map[Function[head, ToString[Unevaluated[head]], HoldAllComplete], #] &,
                 {modified , heldHeads}]]
            },
            Remove @@ Names[tempContext <> "*"];
            result]]]];

It won't win the elegance contests, and may be not very clean, but it seems to do what you requested:

In[270]:= MakeBoxesStop[Graphics[Disk[]]]

Out[270]= Graphics[Disk[List[0, 0]]]

If you don't want expression inside MakeBoxesStop to evaluate, add the appropriate attributes and Unevaluated wrappers in the body.

EDIT

The following simple box-making function is based on the Mathematica parser posted here:

Clear[toBoxes];
toBoxes[expr_] :=
  First[parse[tokenize[ToString@FullForm[expr]]] //. {
    head_String[elem_] :>    RowBox[{head, "[", elem, "]"}], 
    head_String[elems___] :>  RowBox[{head, "[", RowBox[Riffle[{elems}, ","]], "]"}]}]

Then, we need:

Clear[MakeBoxesStopAlt];
MakeBoxesStopAlt /: MakeBoxes[MakeBoxesStopAlt[expr_], form_] :=  toBoxes[expr]

For example:

In[327]:= MakeBoxesStopAlt[Graphics[Disk[]]]

Out[327]= Graphics[Disk[List[0, 0]]]

Is it possible to create MakeBoxesStop wrapper?

2 Answers