/// <summary>
/// Initializes a new instance of the <see cref="UvssLexerToken"/> structure.
/// </summary>
/// <param name="type">A <see cref="UvssLexerTokenType"/> value that indicates the token's type.</param>
/// <param name="sourceOffset">The token's offset within the source text.</param>
/// <param name="sourceLength">The token's length within the source text.</param>
/// <param name="sourceLine">The index of the line on which the token appears in the source text.</param>
/// <param name="sourceColumn">The index of the column in which the token appears in the source text.</param>
/// <param name="text">The token text.</param>
public UvssLexerToken(UvssLexerTokenType type,
Int32 sourceOffset, Int32 sourceLength, Int32 sourceLine, Int32 sourceColumn, String text)
{
this.Type = type;
this.SourceOffset = sourceOffset;
this.SourceLength = sourceLength;
this.SourceLine = sourceLine;
this.SourceColumn = sourceColumn;
this.Text = text;
}
/// <summary>
/// Initializes a new instance of the <see cref="UvssLexerToken"/> structure.
/// </summary>
/// <param name="type">A <see cref="UvssLexerTokenType"/> value that indicates the token's type.</param>
/// <param name="sourceOffset">The token's offset within the source text.</param>
/// <param name="sourceLength">The token's length within the source text.</param>
/// <param name="sourceLine">The index of the line on which the token appears in the source text.</param>
/// <param name="sourceColumn">The index of the column in which the token appears in the source text.</param>
/// <param name="text">The token text.</param>
public UvssLexerToken(UvssLexerTokenType type,
Int32 sourceOffset, Int32 sourceLength, Int32 sourceLine, Int32 sourceColumn, String text)
{
this.Type = type;
this.SourceOffset = sourceOffset;
this.SourceLength = sourceLength;
this.SourceLine = sourceLine;
this.SourceColumn = sourceColumn;
this.Text = text;
}
/// <summary>
/// Reads an extended token, such as a comment, which continues until reaching some termination condition.
/// </summary>
/// <param name="source">The source string.</param>
/// <param name="position">The position at which the token begins.</param>
/// <param name="tokenType">The token's type.</param>
/// <param name="tokenText">The token's text.</param>
private static void ReadExtendedToken(String source, Int32 position,
ref UvssLexerTokenType tokenType, ref String tokenText)
{
switch (tokenType)
{
case UvssLexerTokenType.SingleLineComment:
ReadSingleLineComment(source, position, ref tokenType, ref tokenText);
break;
case UvssLexerTokenType.MultiLineComment:
ReadMultiLineComment(source, position, ref tokenType, ref tokenText);
break;
}
}
/// <summary>
/// Initializes a new instance of the <see cref="UvssLexerToken"/> structure.
/// </summary>
/// <param name="tokenType">The token's type.</param>
/// <param name="start">The index of the token within the source text.</param>
/// <param name="length">The length of the token within the source text.</param>
/// <param name="line">The line of source code that contains the token.</param>
/// <param name="value">The token's associated value.</param>
public UvssLexerToken(UvssLexerTokenType tokenType, Int32 start, Int32 length, Int32 line, String value = null)
{
this.tokenType = tokenType;
this.start = start;
this.length = length;
this.line = line;
switch (tokenType)
{
case UvssLexerTokenType.WhiteSpace:
this.value = " ";
break;
case UvssLexerTokenType.OpenParenthesis:
this.value = "(";
break;
case UvssLexerTokenType.CloseParenthesis:
this.value = ")";
break;
case UvssLexerTokenType.OpenCurlyBrace:
this.value = "{";
break;
case UvssLexerTokenType.CloseCurlyBrace:
this.value = "}";
break;
case UvssLexerTokenType.Colon:
this.value = ":";
break;
case UvssLexerTokenType.Semicolon:
this.value = ";";
break;
case UvssLexerTokenType.Comma:
this.value = ",";
break;
case UvssLexerTokenType.UniversalSelector:
this.value = "*";
break;
default:
this.value = value;
break;
}
}
/// <summary>
/// Reads a multi-line comment token starting at the specified position in the source.
/// </summary>
/// <param name="source">The source string.</param>
/// <param name="position">The source position at which the comment token begins.</param>
/// <param name="tokenType">The token's type.</param>
/// <param name="tokenText">The full text of the multi-line comment token.</param>
private static void ReadMultiLineComment(String source, Int32 position,
ref UvssLexerTokenType tokenType, ref String tokenText)
{
var offset = position;
var length = source.Length - position;
for (int i = position + tokenText.Length; i < source.Length - 1; i++)
{
if (source[i] == '*' && source[i + 1] == '/')
{
length = (i - offset) + 2;
break;
}
}
tokenText = source.Substring(offset, length);
}
/// <summary>
/// Given a <see cref="Match"/> instance, determines the type and text of the corresponding lexer token.
/// </summary>
/// <param name="match">The <see cref="Match"/> instance to evaluate.</param>
/// <param name="tokenType">The lexed token's type.</param>
/// <param name="tokenText">The lexed token's text.</param>
/// <returns>true if the <see cref="Match"/> represented a valid token; otherwise, false.</returns>
private static Boolean GetTokenInfoFromRegexMatch(Match match,
out UvssLexerTokenType tokenType, out String tokenText)
{
for (int i = 1; i < match.Groups.Count; i++)
{
var group = match.Groups[i];
if (group.Success)
{
tokenType = GetTokenTypeFromName(regexGroupNames[i]);
tokenText = group.Value;
return(true);
}
}
tokenType = UvssLexerTokenType.Unknown;
tokenText = null;
return(false);
}
/// <summary>
/// Reads a single-line comment token starting at the specified position in the source.
/// </summary>
/// <param name="source">The source string.</param>
/// <param name="position">The source position at which the comment token begins.</param>
/// <param name="tokenType">The token's type.</param>
/// <param name="tokenText">The full text of the single-line comment token.</param>
private static void ReadSingleLineComment(String source, Int32 position,
ref UvssLexerTokenType tokenType, ref String tokenText)
{
var offset = position;
var length = tokenText.Length;
for (int i = position + tokenText.Length; i < source.Length; i++)
{
if (source.Length == i + 1)
{
length = source.Length - offset;
break;
}
if ((source[i] == '\r' && source[i + 1] == '\n') || source[i] == '\n')
{
length = i - offset;
break;
}
}
tokenText = source.Substring(offset, length);
}
/// <summary>
/// Reads a multi-line comment token starting at the specified position in the source.
/// </summary>
/// <param name="source">The source string.</param>
/// <param name="position">The source position at which the comment token begins.</param>
/// <param name="tokenType">The token's type.</param>
/// <param name="tokenText">The full text of the multi-line comment token.</param>
private static void ReadMultiLineComment(String source, Int32 position,
ref UvssLexerTokenType tokenType, ref String tokenText)
{
var offset = position;
var length = source.Length - position;
for (int i = position + tokenText.Length; i < source.Length - 1; i++)
{
if (source[i] == '*' && source[i + 1] == '/')
{
length = (i - offset) + 2;
break;
}
}
tokenText = source.Substring(offset, length);
}
/// <summary>
/// Throws an exception if the specified token does not match the specified parameters.
/// </summary>
/// <param name="state">The parser state.</param>
/// <param name="token">The token to evaluate.</param>
/// <param name="type">The desired token type.</param>
/// <param name="value">The desired token value.</param>
private static void MatchTokenOrFail(UvssParserState state, UvssLexerToken? token, UvssLexerTokenType type, String value = null)
{
if (token == null)
ThrowUnexpectedEOF(state);
if (token.Value.TokenType != type)
ThrowExpectedToken(state, token.Value, type);
if (value != null && !String.Equals(token.Value.Value, value, StringComparison.OrdinalIgnoreCase))
ThrowExpectedValue(state, token.Value, value);
}
/// <summary>
/// Gets a value indicating whether the specified token is a match for the specified parameters.
/// </summary>
/// <param name="token">The token to evaluate.</param>
/// <param name="type">The desired token type.</param>
/// <param name="value">The desired token value.</param>
/// <returns><c>true</c> if the specified token is a match; otherwise, <c>false</c>.</returns>
private static Boolean MatchToken(UvssLexerToken? token, UvssLexerTokenType type, String value = null)
{
if (token == null)
return false;
if (token.Value.TokenType != type)
return false;
if (value != null && !String.Equals(token.Value.Value, value, StringComparison.OrdinalIgnoreCase))
return false;
return true;
}
/// <summary>
/// Attempts to consume a punctuation token.
/// </summary>
private static Boolean ConsumePunctuation(UvssLexerTokenType type, Char punctuation, String input, IList<UvssLexerToken> output, Int32 line, ref Int32 ix)
{
if (IsPastEndOfStream(input, ix))
return false;
if (input[ix] == punctuation)
{
var token = new UvssLexerToken(type, ix, 1, line);
output.Add(token);
ix++;
return true;
}
return false;
}
/// <summary>
/// Determines whether the last token in the output sequence has the specified type.
/// </summary>
private static Boolean LastTokenHasType(IList<UvssLexerToken> output, UvssLexerTokenType type)
{
if (output.Count == 0)
return false;
var token = output[output.Count - 1];
return token.TokenType == type;
}
/// <summary>
/// Reads a single-line comment token starting at the specified position in the source.
/// </summary>
/// <param name="source">The source string.</param>
/// <param name="position">The source position at which the comment token begins.</param>
/// <param name="tokenType">The token's type.</param>
/// <param name="tokenText">The full text of the single-line comment token.</param>
private static void ReadSingleLineComment(String source, Int32 position,
ref UvssLexerTokenType tokenType, ref String tokenText)
{
var offset = position;
var length = tokenText.Length;
for (int i = position + tokenText.Length; i < source.Length; i++)
{
if (source.Length == i + 1)
{
length = source.Length - offset;
break;
}
if ((source[i] == '\r' && source[i + 1] == '\n') || source[i] == '\n')
{
length = i - offset;
break;
}
}
tokenText = source.Substring(offset, length);
}
/// <summary>
/// Retrieves all of the tokens between a matching pair of tokens.
/// </summary>
/// <param name="state">The parser state.</param>
/// <param name="start">The type of the first token in the matching pair.</param>
/// <param name="end">The type of the second token in the matching pair.</param>
/// <returns>A collection containing the tokens between the specified matching pair of tokens.</returns>
private static IList<UvssLexerToken> GetTokensBetweenMatchingPair(UvssParserState state, UvssLexerTokenType start, UvssLexerTokenType end)
{
if (state.CurrentToken.TokenType != start)
ThrowExpectedToken(state, state.CurrentToken, start);
var level = 1;
var tokens = new List<UvssLexerToken>();
state.Advance();
while (true)
{
if (state.IsPastEndOfStream)
ThrowUnterminatedSequence(state);
var token = state.Consume();
if (token.TokenType == start)
{
level++;
}
else if (token.TokenType == end)
{
level--;
}
if (level == 0)
{
break;
}
tokens.Add(token);
}
return tokens;
}
/// <summary>
/// Reads an extended token, such as a comment, which continues until reaching some termination condition.
/// </summary>
/// <param name="source">The source string.</param>
/// <param name="position">The position at which the token begins.</param>
/// <param name="tokenType">The token's type.</param>
/// <param name="tokenText">The token's text.</param>
private static void ReadExtendedToken(String source, Int32 position,
ref UvssLexerTokenType tokenType, ref String tokenText)
{
switch (tokenType)
{
case UvssLexerTokenType.SingleLineComment:
ReadSingleLineComment(source, position, ref tokenType, ref tokenText);
break;
case UvssLexerTokenType.MultiLineComment:
ReadMultiLineComment(source, position, ref tokenType, ref tokenText);
break;
}
}
/// <summary>
/// Given a <see cref="Match"/> instance, determines the type and text of the corresponding lexer token.
/// </summary>
/// <param name="match">The <see cref="Match"/> instance to evaluate.</param>
/// <param name="tokenType">The lexed token's type.</param>
/// <param name="tokenText">The lexed token's text.</param>
/// <returns>true if the <see cref="Match"/> represented a valid token; otherwise, false.</returns>
private static Boolean GetTokenInfoFromRegexMatch(Match match,
out UvssLexerTokenType tokenType, out String tokenText)
{
for (int i = 1; i < match.Groups.Count; i++)
{
var group = match.Groups[i];
if (group.Success)
{
tokenType = GetTokenTypeFromName(regexGroupNames[i]);
tokenText = group.Value;
return true;
}
}
tokenType = UvssLexerTokenType.Unknown;
tokenText = null;
return false;
}
/// <summary>
/// Throws an exception indicating that an expected token was not found.
/// </summary>
/// <param name="state">The parser state.</param>
/// <param name="token">The invalid token.</param>
/// <param name="expected">The expected token type.</param>
private static void ThrowExpectedToken(UvssParserState state, UvssLexerToken token, UvssLexerTokenType expected)
{
var lineNumber = token.Line;
throw new UvssException(PresentationStrings.StyleSheetSyntaxExpectedToken.Format(lineNumber, token.TokenType, expected));
}
