public static string Interpret(Atom.MathList mathList, System.Func <string, string>?errorLaTeX = null)
{
errorLaTeX ??= error => $@"\color{{red}}\text{{{Atom.LaTeXParser.EscapeAsLaTeX(error)}}}";
(Atom.MathList left, Atom.MathList right)? equation = null;
for (var i = 0; i < mathList.Count; i++)
{
if (mathList[i] is Atom.Atoms.Relation {
Nucleus: "="
})
private MathList?BuildInternal(bool oneCharOnly, char stopChar = '\0')
{
if (oneCharOnly && stopChar > '\0')
{
throw new InvalidCodePathException("Cannot set both oneCharOnly and stopChar");
}
var r = new MathList();
MathAtom?prevAtom = null;
while (HasCharacters)
{
if (Error != null)
{
return(null);
}
MathAtom atom;
switch (GetNextCharacter())
{
case '^' when oneCharOnly:
case '}' when oneCharOnly:
case '_' when oneCharOnly:
case '&' when oneCharOnly:
// this is not the character we are looking for. They are for the caller to look at.
UnlookCharacter();
return(r);
case var ch when stopChar > '\0' && ch == stopChar:
return(r);
case '^':
if (prevAtom == null || prevAtom.Superscript != null || !prevAtom.ScriptsAllowed)
{
prevAtom = new Ordinary(string.Empty);
r.Add(prevAtom);
}
// this is a superscript for the previous atom.
// note, if the next char is StopChar, it will be consumed and doesn't count as stop.
prevAtom.Superscript = this.BuildInternal(true);
continue;
case '_':
if (prevAtom == null || prevAtom.Subscript != null || !prevAtom.ScriptsAllowed)
{
prevAtom = new Ordinary(string.Empty);
r.Add(prevAtom);
}
// this is a subscript for the previous atom.
// note, if the next char is StopChar, it will be consumed and doesn't count as stop.
prevAtom.Subscript = this.BuildInternal(true);
continue;
case '{':
MathList?sublist;
if (_currentEnvironment != null && _currentEnvironment.Name == null)
{
// \\ or \cr which do not have a corrosponding \end
var oldEnv = _currentEnvironment;
_currentEnvironment = null;
sublist = BuildInternal(false, '}');
_currentEnvironment = oldEnv;
}
else
{
sublist = BuildInternal(false, '}');
}
if (sublist == null)
{
return(null);
}
prevAtom = sublist.Atoms.LastOrDefault();
r.Append(sublist);
if (oneCharOnly)
{
return(r);
}
continue;
#warning TODO Example
//https://phabricator.wikimedia.org/T99369
//https://phab.wmfusercontent.org/file/data/xsimlcnvo42siudvwuzk/PHID-FILE-bdcqexocj5b57tj2oezn/math_rendering.png
//dt, \text{d}t, \partial t, \nabla\psi \\ \underline\overline{dy/dx, \text{d}y/\text{d}x, \frac{dy}{dx}, \frac{\text{d}y}{\text{d}x}, \frac{\partial^2}{\partial x_1\partial x_2}y} \\ \prime,
case '}' when oneCharOnly || stopChar != 0:
throw new InvalidCodePathException("This should have been handled before.");
case '}':
SetError("Missing opening brace");
return(null);
case '\\':
var command = ReadCommand();
var done = StopCommand(command, r, stopChar);
if (done != null)
{
return(done);
}
if (Error != null)
{
return(null);
}
if (ApplyModifier(command, prevAtom))
{
continue;
}
if (LaTeXDefaults.FontStyles.TryGetValue(command, out var fontStyle))
{
var oldSpacesAllowed = _textMode;
var oldFontStyle = _currentFontStyle;
_textMode = (command == "text");
_currentFontStyle = fontStyle;
var childList = BuildInternal(true);
if (childList == null)
{
return(null);
}
_currentFontStyle = oldFontStyle;
_textMode = oldSpacesAllowed;
prevAtom = childList.Atoms.LastOrDefault();
r.Append(childList);
if (oneCharOnly)
{
return(r);
}
continue;
}
switch (AtomForCommand(command, stopChar))
{
case null:
SetError(Error ?? "Internal error");
return(null);
case var a:
atom = a;
break;
}
break;
case '&': // column separation in tables
if (_currentEnvironment != null)
{
return(r);
}
var table = BuildTable(null, r, false, stopChar);
if (table == null)
{
return(null);
}
return(new MathList(table));
case '\'': // this case is NOT in iosMath
int i = 1;
while (ExpectCharacter('\''))
{
i++;
}
atom = new Prime(i);
break;
case ' ' when _textMode:
atom = new Ordinary(" ");
break;
case var ch when ch <= sbyte.MaxValue:
if (LaTeXDefaults.ForAscii((sbyte)ch) is MathAtom asciiAtom)
{
atom = asciiAtom;
}
else
{
continue; // Ignore ASCII spaces and control characters
}
break;
case var ch:
// not a recognized character, display it directly
atom = new Ordinary(ch.ToStringInvariant());
break;
}
atom.FontStyle = _currentFontStyle;
r.Add(atom);
prevAtom = atom;
if (oneCharOnly)
{
return(r); // we consumed our character.
}
}
if (stopChar > 0)
{
if (stopChar == '}')
{
SetError("Missing closing brace");
}
else
{
// we never found our stop character.
SetError("Expected character not found: " + stopChar.ToStringInvariant());
}
}
return(r);
}
