private Atom AttachScripts(
TexFormula formula,
SourceSpan value,
ref int position,
Atom atom,
bool skipWhiteSpace,
ICommandEnvironment environment)
{
if (skipWhiteSpace)
{
SkipWhiteSpace(value, ref position);
}
var initialPosition = position;
if (position == value.Length)
{
return(atom);
}
// Check for prime marks.
var primesRowAtom = new RowAtom(new SourceSpan(value.Source, position, 0));
int i = position;
while (i < value.Length)
{
if (value[i] == primeChar)
{
primesRowAtom = primesRowAtom.Add(SymbolAtom.GetAtom("prime", value.Segment(i, 1)));
position++;
}
else if (!IsWhiteSpace(value[i]))
{
break;
}
i++;
}
var primesRowSource = new SourceSpan(
value.Source,
primesRowAtom.Source.Start,
position - primesRowAtom.Source.Start);
primesRowAtom = primesRowAtom.WithSource(primesRowSource);
if (primesRowAtom.Elements.Count > 0)
{
atom = new ScriptsAtom(primesRowAtom.Source, atom, null, primesRowAtom);
}
if (position == value.Length)
{
return(atom);
}
TexFormula superscriptFormula = null;
TexFormula subscriptFormula = null;
var ch = value[position];
if (ch == superScriptChar)
{
// Attach superscript.
position++;
superscriptFormula = ReadScript(formula, value, ref position, environment);
SkipWhiteSpace(value, ref position);
if (position < value.Length && value[position] == subScriptChar)
{
// Attach subscript also.
position++;
subscriptFormula = ReadScript(formula, value, ref position, environment);
}
}
else if (ch == subScriptChar)
{
// Add subscript.
position++;
subscriptFormula = ReadScript(formula, value, ref position, environment);
SkipWhiteSpace(value, ref position);
if (position < value.Length && value[position] == superScriptChar)
{
// Attach superscript also.
position++;
superscriptFormula = ReadScript(formula, value, ref position, environment);
}
}
if (superscriptFormula == null && subscriptFormula == null)
{
return(atom);
}
// Check whether to return Big Operator or Scripts.
var subscriptAtom = subscriptFormula?.RootAtom;
var superscriptAtom = superscriptFormula?.RootAtom;
if (atom.GetRightType() == TexAtomType.BigOperator)
{
var source = value.Segment(atom.Source.Start, position - atom.Source.Start);
if (atom is BigOperatorAtom typedAtom)
{
return(new BigOperatorAtom(
source,
typedAtom.BaseAtom,
subscriptAtom,
superscriptAtom,
typedAtom.UseVerticalLimits));
}
return(new BigOperatorAtom(source, atom, subscriptAtom, superscriptAtom));
}
else
{
var source = new SourceSpan(value.Source, initialPosition, position - initialPosition);
return(new ScriptsAtom(source, atom, subscriptAtom, superscriptAtom));
}
}
private Atom AttachScripts(TexFormula formula, string value, ref int position, Atom atom)
{
if (position == value.Length)
{
return(atom);
}
if (value[position] == superScriptChar || value[position] == subScriptChar)
{
if (position == value.Length - 1)
{
position++;
return(atom);
}
}
else
{
return(atom);
}
TexFormula superscriptFormula = null;
TexFormula subscriptFormula = null;
//0: Undetermined; 1: Not Yet; 2: Yes, we are; 3: Yes, and make it smaller
int markAsBig = 0;
//0: In Beginning;1: We are in _;2: we are in ^
int lastIsSuper = 0;
while (position < value.Length)
{
var ch = value[position];
if (ch == superScriptChar || ch == subScriptChar)
{
if (++position < value.Length && (value[position] == ch))
{
markAsBig = 2;
if (++position < value.Length && (value[position] == ch))
{
markAsBig = 3;
position++;
}
}
bool v = ch == superScriptChar;
if ((v ? superscriptFormula : subscriptFormula) == null)
{
lastIsSuper = v ? 2 : 1;
}
continue;
}
else if (ch == rightGroupChar || (value[position - 1] != '^' && value[position - 1] != '_'))
{
break;
}
if (lastIsSuper == 2)
{
if (superscriptFormula == null)
{
superscriptFormula = ReadScript(formula, value, ref position);
}
else
{
position--;
superscriptFormula.RootAtom = AttachScripts(formula, value, ref position, superscriptFormula.RootAtom);
}
}
else if (lastIsSuper == 1)
{
if (subscriptFormula == null)
{
subscriptFormula = ReadScript(formula, value, ref position);
}
else
{
position--;
subscriptFormula.RootAtom = AttachScripts(formula, value, ref position, subscriptFormula.RootAtom);
}
}
else
{
break;
}
}
if (superscriptFormula == null && subscriptFormula == null)
{
return(atom);
}
// Check whether to return Big Operator or Scripts.
if (atom != null && (atom.GetRightType() == CharType.BigOperator || markAsBig >= 2))
{
return(BigOperatorAtom.Get(atom, subscriptFormula == null ? null : subscriptFormula.GetRoot,
superscriptFormula == null ? null : superscriptFormula.GetRoot, markAsBig == 3));
}
else
{
return(ScriptsAtom.Get(atom, subscriptFormula == null ? null : subscriptFormula.GetRoot,
superscriptFormula == null ? null : superscriptFormula.GetRoot));
}
}
