2d print

[mmatera]

This is a kind of experiment. In WMA, in opposition to InputForm which produces an "inline" representation of an expression, OutputForm consists in a "2D" text-like representation of an expression. There are some examples:

In[1]:= a/b                                                                     

        a
Out[1]= -
        b

In[2]:= Sqrt[a]                                                                 

Out[2]= Sqrt[a]

In[3]:= Integrate[f[x],x]                                                       

Out[3]= Integrate[f[x], x]

In[4]:= Sqrt[a]^q                                                               

         q/2
Out[4]= a

In[5]:= MatrixForm[Table[i*j,{i,2},{j,2}]]                                      

Out[5]//MatrixForm= 1   2

                    2   4

In this way, the output in OutputForm is formatted in a similar way to the prettyprint format of Sympy.

This PR provides a way to partially reproduce this behavior when an expression is wrapped by OutputForm, and a variable $Use2DOutputForm is set to True.

The support is not complete, and probably can be improved using the code in sympy.prettyprint. Also, it currently does not work in Mathics-Django, because it is not able to print strings with line breaks.

Here are some examples in Mathics, under this branch:

In[1]:=  $Use2DOutputForm=True
Out[1]= True

In[2]:= OutputForm[a/b]
Out[2]= 
         a 
        ---
         b 

In[3]:= OutputForm[Sqrt[a]]
Out[3]= 
        __
        |a

In[4]:= Integrate[F[x],x]^2//OutputForm
Out[4]= 
                   2
         /+         
         |  F[x] dx 
        +/          

In[5]:= MatrixForm[Table[i*j,{i,2},{j,2}]]
Out[5]//MatrixForm= 1   2
                    
                    2   4