/// <summary>
/// Match is a static method that determines whether
/// or not the token starting at
/// <paramref name="begin">begin</paramref>
/// is an C# identifier.
/// </summary>
/// <param name="begin">begin</param>
/// <param name="end">end</param>
internal static bool Match(Position begin, Position end)
{
if (begin == end) {
return false;
}
char read = begin.Get();
return Ctype.IsLetter(read) || read == '_';
}
private void SplitIntoLines()
{
Position begin = new Position(contents, 0);
Position end = new Position(contents, contents.Length);
Position pos;
bool inComment = false;
while ((pos = Utility.Find(begin, end, '\r')) != end) {
lines.Add(new Line(begin, pos, ref inComment));
begin = ++pos;
if (begin != end && begin.Get() == '\n') {
++begin;
}
}
// last line might not have a terminating newline
if (begin != end) {
lines.Add(new Line(begin, pos, ref inComment));
}
// remove trailing blank lines
while (lines.Count > 0 && ((Line)lines[lines.Count-1]).IsBlank()) {
lines.RemoveAt(lines.Count - 1);
}
}
internal Line(Position begin, Position end, ref bool inComment)
{
while (begin != end) {
Position pos;
if (inComment || MultiLineComment.Match(begin, end)) {
pos = MultiLineComment.Eat(begin, end);
if (pos != end) {
++pos; ++pos; inComment = false;
} else {
inComment = true;
}
tokens.Add(MultiLineComment.MakeToken(begin, pos));
}
else if (OneLineComment.Match(begin, end)) {
pos = OneLineComment.Eat(begin, end);
tokens.Add(OneLineComment.MakeToken(begin, pos));
}
else if (WhiteSpace.Match(begin, end)) {
pos = WhiteSpace.Eat(begin, end);
tokens.Add(WhiteSpace.MakeToken(begin, pos));
}
else if (Identifier.Match(begin, end)) {
pos = Identifier.Eat(begin, end);
if (Keyword.Match(begin, pos)) {
tokens.Add(Keyword.MakeToken(begin, pos));
} else {
tokens.Add(Identifier.MakeToken(begin, pos));
}
}
else if (Directive.Match(begin, end)) {
pos = Directive.Eat(begin, end);
tokens.Add(Directive.MakeToken(begin, pos));
}
else {
pos = end;
tokens.Add(Other.MakeToken(begin, end));
}
begin = pos;
}
}
internal WhiteSpaceToken(Position begin, Position end)
: base(begin, end)
{
}
internal static bool Match(Position begin, Position end)
{
return begin != end && Ctype.IsWhiteSpace(begin.Get());
}
internal static IWhiteSpaceToken MakeToken(Position begin, Position end)
{
return new WhiteSpaceToken(begin, end);
}
internal static Position Eat(Position begin, Position end)
{
return Utility.FindIf(begin, end, notWhiteSpace);
}
internal IdentifierToken(Position begin, Position end)
: base(begin, end)
{
}
/// <summary>
/// MakeToken is a static method that creates and
/// returns a token representing an identifier that
/// starts at
/// <paramref name="begin">begin</paramref>
/// and finishes just before
/// <paramref name="end">end</paramref>.
/// </summary>
/// <param name="begin">begin</param>
/// <param name="end">end</param>
internal static IIdentifierToken MakeToken(Position begin, Position end)
{
return new IdentifierToken(begin, end);
}
/// <summary>
/// Eat is a static method that eats the identifier
/// token assumed to start at
/// <paramref name="begin">begin</paramref>.
/// </summary>
/// <param name="begin">begin</param>
/// <param name="end">end</param>
/// <returns>
/// A Position representing the first
/// character not in the identifier token. The
/// returned Position is useful as the second
/// parameter to the MakeToken method.
/// </returns>
internal static Position Eat(Position begin, Position end)
{
return Utility.FindIf(begin, end, notIdentifier);
}