I want to draw math diagrams, which I think falls in the category of vector graphics.

I used tikz for a long time, but the language is not clean enough for me and feels like a hack rather than a proper tool. For example there are so many backslashes e.g.

\foreach \x in {0,...,4} {
      \foreach \y in {\x,...,4} {
        \x --["\ifthenelse{\x=3 \OR \y=3 \OR \x=\y}{}{\x\y}",sloped] \y;
  }}

Then I tried gnuplot, which seems to focus on plotting data rather than drawing diagrams. For example, to draw a simple circle, I need to plot NaN after set object X circle ...:

set xrange [-5:5]
set yrange [-5:5]
set object 1 circle at 0,0 size char 1 fillcolor rgb "black" fillstyle solid
plot NaN

I also tried inkscape, but it's graphical interface, whereas I hate looking for the correct button to click and prefer a markup-language type of tool.

I am going to try asymptote now. Meanwhile, can anyone recommend a good vector graphics markup language that is convenient for creating math diagrams?

Thanks in advance.