public void TestCreateWord()
{
var w = new Word( Tag.True, "true" );
Assert.AreEqual( Tag.True, w.Tag );
Assert.AreEqual( "true", w.Lexeme );
}
public Token Scan( StringReader reader )
{
for ( ;; _peek = (char) reader.Read() )
{
if ( _peek == ' ' || _peek == '\t' )
continue;
if ( _peek == '\n' )
Line += 1;
else
break;
}
if ( Char.IsDigit( _peek ) )
{
var buf = new StringBuilder();
do
{
buf.Append( _peek );
_peek = (char) reader.Read();
} while( Char.IsDigit( _peek ) );
if ( _peek == '.' )
{
buf.Append( _peek );
_peek = (char) reader.Read();
while( Char.IsDigit( _peek ) )
{
buf.Append( _peek );
_peek = (char)reader.Read();
}
CultureInfo ci = (CultureInfo)CultureInfo.CurrentCulture.Clone();
ci.NumberFormat.CurrencyDecimalSeparator = ".";
double d = double.Parse( buf.ToString(), NumberStyles.Any, ci );
return new Float( Tag.Float, d );
}
return new Num( Tag.Num, int.Parse( buf.ToString() ) );
}
if ( _peek == '.' )
{
var buf = new StringBuilder();
buf.Append( _peek );
_peek = (char)reader.Read();
while ( Char.IsDigit( _peek ) )
{
buf.Append( _peek );
_peek = (char)reader.Read();
}
CultureInfo ci = (CultureInfo)CultureInfo.CurrentCulture.Clone();
ci.NumberFormat.CurrencyDecimalSeparator = ".";
double d = double.Parse( buf.ToString(), NumberStyles.Any, ci );
return new Float( Tag.Float, d );
}
if ( Char.IsLetter( _peek ) )
{
var buf = new StringBuilder();
do
{
buf.Append( _peek );
_peek = (char) reader.Read();
} while( Char.IsLetterOrDigit( _peek ) );
string s = buf.ToString();
var w = (Word) _words[s];
if ( w != null )
return w;
w = new Word( Tag.Id, s );
_words.Add( s, w );
return w;
}
if ( _peek == '/' )
{
_peek = (char) reader.Read();
if ( _peek == '/' )
{
_peek = (char) reader.Read();
var buf = new StringBuilder();
do
{
buf.Append( _peek );
_peek = (char) reader.Read();
} while( _peek != '\n' );
return new Comment( Tag.Comment, buf.ToString() );
}
if ( _peek == '*' )
{
var buf = new StringBuilder();
_peek = (char) reader.Read();
while( true )
{
if ( _peek == '*' )
{
_peek = (char) reader.Read();
if ( _peek == '/' )
{
return new Comment( Tag.Comment, buf.ToString() );
}
buf.Append( '*' );
}
else
{
buf.Append( _peek );
_peek = (char) reader.Read();
}
}
}
}
if ( _peek == '<' )
{
var buf = new StringBuilder();
buf.Append( _peek );
_peek = (char) reader.Read();
if ( _peek == '=' )
{
buf.Append( _peek );
_peek = (char) reader.Read();
return new Word( Tag.LessOrEqual, buf.ToString() );
}
return new Word( Tag.Less, buf.ToString() );
}
if ( _peek == '>' )
{
var buf = new StringBuilder();
buf.Append( _peek );
_peek = (char) reader.Read();
if ( _peek == '=' )
{
buf.Append( _peek );
_peek = (char) reader.Read();
return new Word( Tag.BetterOrEqual, buf.ToString() );
}
return new Word( Tag.Better, buf.ToString() );
}
if ( _peek == '=' )
{
var buf = new StringBuilder();
buf.Append( _peek );
_peek = (char) reader.Read();
if ( _peek == '=' )
{
buf.Append( _peek );
_peek = (char) reader.Read();
return new Word( Tag.Equal, buf.ToString() );
}
}
if ( _peek == '!' )
{
var buf = new StringBuilder();
buf.Append( _peek );
_peek = (char) reader.Read();
if ( _peek == '=' )
{
buf.Append( _peek );
_peek = (char) reader.Read();
return new Word( Tag.NotEqual, buf.ToString() );
}
}
var t = new Token( _peek );
_peek = ' ';
return t;
}
private void Reserve( Word word )
{
_words.Add( word.Lexeme, word );
}
