Round trip conversion leads to invalid LaTeX

[Smurf-IV]

Describe the bug

With the correct fix from #57, still get incorrect LaTeX

To Reproduce

• Input is \mathrm{Gap}^2
  

• output from MathListBuilder.MathListToString(mathList)
  is \mathrm{Gap^2}

• Put this into the MathListBuilder -> Build() and it does not convert.

[Smurf-IV]

Also makes a mess of the following
\mathrm{Gap}^2\mathrm{gb} into \mathrm{Gap^2gb}
which removes the "understanding" of this being 2 variables !

[charlesroddie]

It's possible this could be changed. Ideally before that, the purpose of getting a latex string from a mathlist should be decided.

Without speccing this out I do not see a bug here. TeX represents displayed mathematics. It does not necessarily represent what formulas mean. (For example a(b+c) could refer to multiplication or function application.) In your examples the input and the output TeX will be displayed the same way. So the simplification could be done in either step and is valid, unless we agree that specific non-visual information needs encoding inside mathlist or tex.

[Happypig375]

This is a bug in MathList->TeX code. If we use \mathbf instead of \mathrm, aka \mathbf{Gap}^2\mathbf{gb}, the 2 is not bolded and displays as so. However, when we convert the MathList back to TeX, it becomes \mathbf{Gap^2gb} and the 2 becomes bolded.

[Happypig375]

Fixed! Now the result is \mathrm{Gap^{\mathnormal{2}}} which is the true representation of \mathrm{Gap}^2 in CSharpMath.

CSharpMath/CSharpMath.Tests/Atoms/LaTeXBuilderTest.cs

Lines 638 to 652 in 9fef1e1

	[Fact] // This is for https://github.com/verybadcat/CSharpMath/issues/59
	public void TestFontInsideScript() {
	var list = LaTeXBuilder.MathListFromLaTeX(@"\mathbf{Gap}^2");
	Assert.Collection(list,
	CheckAtom<Variable>("G", G => Assert.Equal(FontStyle.Bold, G.FontStyle)),
	CheckAtom<Variable>("a", a => Assert.Equal(FontStyle.Bold, a.FontStyle)),
	CheckAtom<Variable>("p", p => {
	Assert.Equal(FontStyle.Bold, p.FontStyle);
	Assert.Collection(p.Superscript,
	CheckAtom<Number>("2", two => Assert.Equal(FontStyle.Default, two.FontStyle))
	);
	})
	);
	Assert.Equal(@"\mathbf{Gap^{\mathnormal{2}}}", LaTeXBuilder.MathListToLaTeX(list));
	}