/// <summary>
/// Emits a token into the output stream.
/// </summary>
/// <param name="output">The output stream into which to emit the token.</param>
/// <param name="token">The token to emit into the output stream.</param>
/// <param name="lineIndex">The current line index.</param>
/// <param name="columnIndex">The current column index.</param>
/// <param name="options">The lexer's configurable options.</param>
/// <returns>The number of characters by which to advance the lexer's position
/// within the source string.</returns>
private static Int32 EmitToken(IList <UvssLexerToken> output, UvssLexerToken token,
ref Int32 lineIndex, ref Int32 columnIndex, UvssLexerOptions options)
{
HandleLineAndColumnTracking(token.Text, ref lineIndex, ref columnIndex, options);
output.Add(token);
return(token.Text.Length);
}
/// <summary>
/// Tokenizes the specified Ultraviolet StyleSheets (UVSS) string.
/// </summary>
/// <param name="source">The source string to tokenize.</param>
/// <param name="options">The lexer's configurable options, or null to use the default options.</param>
/// <returns>A <see cref="UvssLexerStream"/> instance which produces lexed tokens from the specified source text.</returns>
public static UvssLexerStream Tokenize(String source, UvssLexerOptions options = null)
{
Contract.Require(source, nameof(source));
var instance = new UvssLexer(source, options ?? UvssLexerOptions.Default);
return(new UvssLexerStream(instance));
}
/// <summary>
/// Calculates the length of the specified token text in columns, performing tab expansion if necessary.
/// </summary>
/// <param name="text">The text of the token that is being emitted.</param>
/// <param name="offset">The offset into the token text at which to begin measuring length.</param>
/// <param name="options">The lexer's configurable options.</param>
/// <returns>The length of the specified token text in columns.</returns>
private static Int32 CalculateTokenLengthInColumns(String text, Int32 offset, UvssLexerOptions options)
{
var length = 0;
for (int i = offset; i < text.Length; i++)
{
length += (text[i] == '\t') ? options.TabSize : 1;
}
return(length);
}
/// <summary>
/// Initializes a new instance of the <see cref="UvssLexer"/> class.
/// </summary>
/// <param name="source">The source which is being lexed.</param>
/// <param name="options">The lexer's options.</param>
private UvssLexer(String source, UvssLexerOptions options)
{
this.source = source;
this.options = options;
}
/// <summary>
/// Determines whether the lexer has advanced to a new line and updates the line index accordingly.
/// In addition, this method moves the column index forward by the length of the current token,
/// performing tab expansion as necessary.
/// </summary>
/// <param name="text">The text of the token that is being emitted.</param>
/// <param name="lineIndex">The current line index.</param>
/// <param name="columnIndex">The current column index.</param>
/// <param name="options">The lexer's configurable options.</param>
private static void HandleLineAndColumnTracking(String text,
ref Int32 lineIndex, ref Int32 columnIndex, UvssLexerOptions options)
{
var newlineMatches = regexNewline.Matches(text);
if (newlineMatches.Count > 0)
{
var lineStartOffset = 0;
foreach (Match match in newlineMatches)
{
lineIndex++;
lineStartOffset = match.Index + match.Length;
}
columnIndex = 1 + CalculateTokenLengthInColumns(text, lineStartOffset, options);
}
else
{
columnIndex += CalculateTokenLengthInColumns(text, 0, options);
}
}
/// <summary>
/// Determines whether the lexer has advanced to a new line and updates the line index accordingly.
/// In addition, this method moves the column index forward by the length of the current token,
/// performing tab expansion as necessary.
/// </summary>
/// <param name="text">The text of the token that is being emitted.</param>
/// <param name="lineIndex">The current line index.</param>
/// <param name="columnIndex">The current column index.</param>
/// <param name="options">The lexer's configurable options.</param>
private static void HandleLineAndColumnTracking(String text,
ref Int32 lineIndex, ref Int32 columnIndex, UvssLexerOptions options)
{
var newlineMatches = regexNewline.Matches(text);
if (newlineMatches.Count > 0)
{
var lineStartOffset = 0;
foreach (Match match in newlineMatches)
{
lineIndex++;
lineStartOffset = match.Index + match.Length;
}
columnIndex = 1 + CalculateTokenLengthInColumns(text, lineStartOffset, options);
}
else
{
columnIndex += CalculateTokenLengthInColumns(text, 0, options);
}
}
/// <summary>
/// Emits a token into the output stream.
/// </summary>
/// <param name="output">The output stream into which to emit the token.</param>
/// <param name="token">The token to emit into the output stream.</param>
/// <param name="lineIndex">The current line index.</param>
/// <param name="columnIndex">The current column index.</param>
/// <param name="options">The lexer's configurable options.</param>
/// <returns>The number of characters by which to advance the lexer's position
/// within the source string.</returns>
private static Int32 EmitToken(IList<UvssLexerToken> output, UvssLexerToken token,
ref Int32 lineIndex, ref Int32 columnIndex, UvssLexerOptions options)
{
HandleLineAndColumnTracking(token.Text, ref lineIndex, ref columnIndex, options);
output.Add(token);
return token.Text.Length;
}
/// <summary>
/// Calculates the length of the specified token text in columns, performing tab expansion if necessary.
/// </summary>
/// <param name="text">The text of the token that is being emitted.</param>
/// <param name="offset">The offset into the token text at which to begin measuring length.</param>
/// <param name="options">The lexer's configurable options.</param>
/// <returns>The length of the specified token text in columns.</returns>
private static Int32 CalculateTokenLengthInColumns(String text, Int32 offset, UvssLexerOptions options)
{
var length = 0;
for (int i = offset; i < text.Length; i++)
length += (text[i] == '\t') ? options.TabSize : 1;
return length;
}
/// <summary>
/// Tokenizes the specified Ultraviolet StyleSheets (UVSS) string.
/// </summary>
/// <param name="source">The source string to tokenize.</param>
/// <param name="options">The lexer's configurable options, or null to use the default options.</param>
/// <returns>A <see cref="UvssLexerStream"/> instance which produces lexed tokens from the specified source text.</returns>
public static UvssLexerStream Tokenize(String source, UvssLexerOptions options = null)
{
Contract.Require(source, nameof(source));
var instance = new UvssLexer(source, options ?? UvssLexerOptions.Default);
return new UvssLexerStream(instance);
}
/// <summary>
/// Initializes a new instance of the <see cref="UvssLexer"/> class.
/// </summary>
/// <param name="source">The source which is being lexed.</param>
/// <param name="options">The lexer's options.</param>
private UvssLexer(String source, UvssLexerOptions options)
{
this.source = source;
this.options = options;
}
