// NOTE: we capture entire lines as "tokens"; this class's job is to classify individual line entries (and tag comment/whitespace trivia), not to parse raw tokens
public IniToken GetNextToken()
{
var leadingTrivia = new List <IniTrivia>();
// NOTE: this loop will continue until we parse a line or read eof of file
while (true)
{
var nextLine = this.ReadIniTextLine();
if (nextLine is null)
{
return(new IniToken(IniTokenKind.EndOfFile, new List <char>() /* empty lexeme, rather than null */, IniLineTerminatorOption.None, leadingTrivia, null));
}
var lexeme = nextLine.Text !;
var lineTerminator = nextLine.LineTerminator;
// check for empty lines
if (lexeme.Count == 0)
{
// empty line; treat this as trivia
var whitespaceTrivia = new IniTrivia(IniTriviaKind.Whitespace, lexeme, lineTerminator);
leadingTrivia.Add(whitespaceTrivia);
// capture another line of text
continue;
}
else
{
// check for comment lines
if (lexeme.First() == ';')
{
// comment; capture this as trivia
var commentTrivia = new IniTrivia(IniTriviaKind.Comment, lexeme, lineTerminator);
leadingTrivia.Add(commentTrivia);
// capture another line of text
continue;
}
// check for whitespace lines
var lineIsWhitespace = lexeme.All(ch =>
{
switch (ch)
{
case ' ':
case '\t':
return(true);
default:
return(false);
}
});
if (lineIsWhitespace == true)
{
var whitespaceTrivia = new IniTrivia(IniTriviaKind.Whitespace, lexeme, lineTerminator);
leadingTrivia.Add(whitespaceTrivia);
// capture another line of text
continue;
}
// check for an EOF marker
if (lexeme.Count == 1 && lexeme.First() == (char)0x1A /* EOF marker */)
{
// EOF marker; this will end our text capture
return(new IniToken(IniTokenKind.EndOfFile, lexeme, lineTerminator, leadingTrivia, null));
}
// now categorize our lexeme (or mark it as invalid)
char?firstNonWhitespaceCharacter = null;
foreach (var ch in lexeme)
{
switch (ch)
{
case ' ':
case '\t':
continue;
default:
firstNonWhitespaceCharacter = ch;
break;
}
if (firstNonWhitespaceCharacter is not null)
{
break;
}
}
// check for sections
if (firstNonWhitespaceCharacter == '[')
{
// make sure that the line contains an ending (right) bracket
var indexOfRightBracket = lexeme.IndexOf(']');
if (indexOfRightBracket > 0)
{
// found right bracket; make sure that the line does not contain any non-whitespace characters after the bracket
for (var index = indexOfRightBracket + 1; index < lexeme.Count; index += 1)
{
switch (lexeme[index])
{
case ' ':
case '\t':
// whitespace
break;
default:
// if we encounter any non-whitespace characters, this an invalid token
return(new IniToken(IniTokenKind.Invalid, lexeme, lineTerminator, leadingTrivia, null));
}
}
// this section is valid; return it now
return(new IniToken(IniTokenKind.Section, lexeme, lineTerminator, leadingTrivia, null));
}
else
{
// this line does not have a closing bracket for the section
return(new IniToken(IniTokenKind.Invalid, lexeme, lineTerminator, leadingTrivia, null));
}
}
// NOTE: at this point, the line should be a property (i.e. key/value pair); anything else is invalid
// check for an equals sign; we will treat anything to the left as the key and anything to the right as the value
var indexOfEqualsCharacter = lexeme.IndexOf('=');
if (indexOfEqualsCharacter >= 0)
{
// key/value pair
// NOTE: our parser is responsible for parsing out the key and value (and dealing with leading/trailing whitespace, double quotes around values, etc.)
return(new IniToken(IniTokenKind.Property, lexeme, lineTerminator, leadingTrivia, null));
}
// anything else is an invalid token
return(new IniToken(IniTokenKind.Invalid, lexeme, lineTerminator, leadingTrivia, null));
}
}
}
private static void AppendTriviaToStringBuilder(IniTrivia trivia, ref StringBuilder builder)
{
builder.Append(trivia.Lexeme.ToArray());
IniFile.AppendLineTerminatorToStringBuilder(trivia.LineTerminator ?? IniLineTerminatorOption.None, ref builder);
}
