private void ParseTopLevel(BibTexLexerCallback callback)
{
int prev_c = c;
while (c < MAX_C)
{
// The `@keyword` must always be preceded by at least one whitespace
// character so as to differentiate it from email addresses, etc.:
// `joe@article` vs. ` @article`
if ('@' != bibtex[c] || !Char.IsWhiteSpace(bibtex[c - 1]))
{
++c;
}
else
{
// Hit a `@` BibTeX command start marker.
// Everything that we looped through thus far is either whitespace or comment or both:
string comment = bibtex.Substring(prev_c, c - prev_c).Trim();
if (!String.IsNullOrEmpty(comment))
{
callback.RaiseComment(comment);
}
// Get this @entry
ParseEntry(callback);
// Skip spaces between entries
ParseWhiteSpace();
prev_c = c;
}
}
callback.RaiseFinished();
}
private void ParseEntry(BibTexLexerCallback callback)
{
// skip initial `@`
++c;
// Get the entry name
int entry_name_start = c;
while (IsNameChar(bibtex[c]))
{
++c;
}
int entry_name_end = c;
string entry_name = bibtex.Substring(entry_name_start, entry_name_end - entry_name_start);
// Check if it is a comment
if (0 == "comment".CompareTo(entry_name.ToLower()))
{
ParseWhiteSpace();
switch (bibtex[c])
{
case '(':
callback.RaiseComment(ParseUntilDelim(callback, ')'));
return;
case '{':
callback.RaiseComment(ParseUntilDelim(callback, '}'));
return;
default:
// b0rked `@comment`: parse until EOL
callback.RaiseComment(ParseUntilDelim(callback, '\n'));
return;
}
}
callback.RaiseEntryName(entry_name);
// Check the length of the entry name
if (entry_name_end == entry_name_start)
{
Exception(callback, "The BibTeX type is missing");
}
// Skip spaces between name and open brackets
ParseWhiteSpace();
// Now an entry is either { xxx } or ( xxx )
switch (/* c < MAX_C ? */ bibtex[c]) // -- optimization
{
case '(':
ParseEntry_Delim(callback, '(', ')');
break;
case '{':
ParseEntry_Delim(callback, '{', '}');
break;
default:
Exception(callback, "Expecting a {0} or {1} to start a BibTeX reference", "(", "{{");
return;
}
}
private void ParseEntry(BibTexLexerCallback callback)
{
try
{
// Check we have our @
if ('@' != bibtex[c])
{
Exception(callback, "Entry should start with @");
return;
}
else
{
++c;
}
// Get the entry name
int entry_name_start = c;
while (IsNameChar(bibtex[c]))
{
++c;
}
int entry_name_end = c;
string entry_name = bibtex.Substring(entry_name_start, entry_name_end - entry_name_start);
// Check if it is a comment
if (0 == "comment".CompareTo(entry_name.ToLower()))
{
ParseUntilDelim(callback, '{'); //Ensure we have an opening {
++c; //Skip it.
callback.RaiseComment(ParseUntilDelim(callback, '}'));
return;
}
callback.RaiseEntryName(entry_name);
// Check the length of the entry name
if (entry_name_end == entry_name_start)
{
Exception(callback, "The BibTeX type is missing");
}
// Skip spaces between name and open brackets
ParseWhiteSpace();
// Now and entry is either { xxx } or ( xxx )
if (false)
{
}
else if ('(' == bibtex[c])
{
ParseEntry_Delim(callback, '(', ')');
}
else if ('{' == bibtex[c])
{
ParseEntry_Delim(callback, '{', '}');
}
else
{
Exception(callback, "Expecting a {0} or {1} to start a BibTeX reference", "(", "{{");
return;
}
}
catch (IndexOutOfRangeException)
{
Exception(callback, "Ran out of characters while reading the entry");
}
}