public static MathList MathListForCharacters(string chars)
{
var r = new MathList();
foreach (char c in chars)
{
r.Add(ForCharacter(c));
}
return(r);
}
public static MathList WithAtoms(List <IMathAtom> atoms)
{
var r = new MathList();
foreach (var atom in atoms)
{
r.Add(atom);
}
return(r);
}
internal MathList StopCommand(string command, MathList list, char stopChar)
{
if (command == "right")
{
if (_currentInnerAtom == null)
{
SetError("Missing \\left");
return(null);
}
_currentInnerAtom.RightBoundary = _BoundaryAtomForDelimiterType("right");
if (_currentInnerAtom.RightBoundary == null)
{
return(null);
}
return(list);
}
if (fractionCommands.ContainsKey(command))
{
bool rule = (command == "over");
var fraction = new Fraction(rule);
var delimiters = fractionCommands[command];
if (delimiters != null)
{
fraction.LeftDelimiter = delimiters.Value.First;
fraction.RightDelimiter = delimiters.Value.Second;
}
fraction.Numerator = list;
fraction.Denominator = BuildInternal(false, stopChar);
if (_error != null)
{
return(null);
}
return(MathLists.WithAtoms(fraction));
}
else if (command == "\\" || command == "cr")
{
if (_currentEnvironment == null)
{
var table = BuildTable(null, list, true, stopChar);
if (table == null)
{
return(null);
}
return(MathLists.WithAtoms(table));
}
else
{
// stop the current list and increment the row count
_currentEnvironment.NRows++;
return(list);
}
}
else if (command == "end")
{
if (_currentEnvironment == null)
{
SetError(@"Missing \begin");
return(null);
}
var env = ReadEnvironment();
if (env == null)
{
return(null);
}
if (env != _currentEnvironment.Name)
{
SetError($"Begin environment name {_currentEnvironment.Name} does not match end environment name {env}");
return(null);
}
_currentEnvironment.Ended = true;
return(list);
}
return(null);
}
internal IMathList BuildInternal(bool oneCharOnly, char stopChar)
{
if (oneCharOnly && stopChar > 0)
{
throw new InvalidOperationException("Cannot set both oneCharOnly and stopChar");
}
var r = new MathList();
IMathAtom prevAtom = null;
while (HasCharacters)
{
if (_error != null)
{
return(null);
}
IMathAtom atom;
var ch = GetNextCharacter();
if (oneCharOnly)
{
if (ch == '^' || ch == '}' || ch == '_' || ch == '&')
{
// this is not the character we are looking for. They are for the caller to look at.
UnlookCharacter();
return(r);
}
}
if (stopChar > 0 && ch == stopChar)
{
return(r);
}
switch (ch)
{
case '^':
if (prevAtom == null || prevAtom.Superscript != null || !prevAtom.ScriptsAllowed)
{
prevAtom = MathAtoms.Create(MathAtomType.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 = MathAtoms.Create(MathAtomType.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 '{':
IMathList 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();
if (oneCharOnly)
{
r.Append(sublist);
return(r);
}
#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,
atom = new Group {
InnerList = sublist
};
break;
case '}':
if (oneCharOnly || stopChar != 0)
{
throw new InvalidCodePathException("This should have been handled before.");
}
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;
}
var fontStyleQ = MathAtoms.FontStyle(command);
if (fontStyleQ.HasValue)
{
var fontStyle = fontStyleQ.Value;
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;
}
atom = AtomForCommand(command, stopChar);
if (atom == null)
{
SetError(_error ?? "Internal error");
return(null);
}
break;
case '&': { // column separation in tables
if (_currentEnvironment != null)
{
return(r);
}
var table = BuildTable(null, r, false, stopChar);
if (table == null)
{
return(null);
}
return(MathLists.WithAtoms(table));
}
case '\'': // this case is NOT in iosMath
int i = 1;
while (ExpectCharacter('\''))
{
i++;
}
atom = new Prime(i);
break;
default:
if (_textMode && ch == ' ')
{
atom = MathAtoms.ForLatexSymbolName(" ");
}
else
{
atom = MathAtoms.ForCharacter(ch);
if (atom == null)
{
// not a recognized character
continue;
}
}
break;
}
if (atom == null)
{
throw new InvalidCodePathException("Atom shouldn't be null");
}
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.ToString());
}
}
return(r);
}
