/// <summary>
/// Break a string into tokens
/// </summary>
/// <param name="s">The string</param>
/// <param name="culture">The Culture to use for this</param>
/// <param name="symbolIsOneChar">Whether to consider every symbol character a separate symbol token</param>
/// <param name="quoteCharacter">Quote character found around quoted literal token</param>
/// <param name="excludedSymbols">List of characters which are not to be considered symbols</param>
/// <returns>Enumerable of tokens</returns>
public static IEnumerable <Token> Tokenise(this string s, CultureInfo culture, bool symbolIsOneChar, char?quoteCharacter, List <char> excludedSymbols)
{
int pos = 0;
Token token = null;
Token lastToken = null;
bool hasWhitespaceBefore = false;
string decimalPoint = culture.NumberFormat.NumberDecimalSeparator;
if (excludedSymbols == null)
{
excludedSymbols = new List <char>();
}
while (pos < s.Length)
{
hasWhitespaceBefore = false;
while (pos < s.Length && char.IsWhiteSpace(s[pos]))
{
pos++;
hasWhitespaceBefore = true;
}
if (pos >= s.Length)
{
yield break;
}
if (quoteCharacter.HasValue && s[pos] == quoteCharacter)
{
token = new QuotedLiteralToken(pos + 1, pos + 1);
}
else if (char.IsNumber(s[pos]))
{
token = new NumberToken(pos, pos + 1);
}
else if (IsSymbolChar(s[pos], excludedSymbols))
{
token = new SymbolToken(pos, pos + 1);
}
else
{
token = new WordToken(pos, pos + 1);
}
pos++;
bool hasDP = false;
while (pos < s.Length && (token is QuotedLiteralToken || !char.IsWhiteSpace(s[pos])))
{
if ((token is NumberToken && char.IsNumber(s[pos])) ||
(token is SymbolToken && IsSymbolChar(s[pos], excludedSymbols) && !symbolIsOneChar) ||
(token is WordToken && !char.IsNumber(s[pos]) && !IsSymbolChar(s[pos], excludedSymbols) && !char.IsWhiteSpace(s[pos])) ||
(token is QuotedLiteralToken && s[pos] != quoteCharacter))
{
token.ExtendRight();
}
else if (token is NumberToken &&
s[pos] == decimalPoint[0] &&
pos + 1 < s.Length &&
char.IsNumber(s[pos + 1]) &&
!hasDP)
{
hasDP = true;
token.ExtendRight();
}
else
{
break;
}
pos++;
}
token.Previous = lastToken;
token.SetValue(s);
token.HasWhitespaceBefore = hasWhitespaceBefore;
if (token is QuotedLiteralToken) // skip final quote
{
pos++;
}
yield return(token);
lastToken = token;
}
}
/// <summary>
/// Break a string into tokens
/// </summary>
/// <param name="s">The string</param>
/// <param name="culture">The Culture to use for this</param>
/// <param name="symbolIsOneChar">Whether to consider every symbol character a separate symbol token</param>
/// <param name="quoteCharacter">Quote character found around quoted literal token</param>
/// <param name="excludedSymbols">List of characters which are not to be considered symbols</param>
/// <returns>Enumerable of tokens</returns>
public static IEnumerable<Token> Tokenise(this string s, CultureInfo culture, bool symbolIsOneChar, char? quoteCharacter, List<char> excludedSymbols)
{
int pos = 0;
Token token = null;
Token lastToken = null;
bool hasWhitespaceBefore = false;
string decimalPoint = culture.NumberFormat.NumberDecimalSeparator;
if (excludedSymbols == null)
excludedSymbols = new List<char>();
while (pos < s.Length)
{
hasWhitespaceBefore = false;
while (pos < s.Length && char.IsWhiteSpace(s[pos]))
{
pos++;
hasWhitespaceBefore = true;
}
if (pos >= s.Length)
yield break;
if (quoteCharacter.HasValue && s[pos] == quoteCharacter)
token = new QuotedLiteralToken(pos + 1, pos + 1);
else if (char.IsNumber(s[pos]))
token = new NumberToken(pos, pos + 1);
else if (IsSymbolChar(s[pos], excludedSymbols))
token = new SymbolToken(pos, pos + 1);
else
token = new WordToken(pos, pos + 1);
pos++;
bool hasDP = false;
while (pos < s.Length && (token is QuotedLiteralToken || !char.IsWhiteSpace(s[pos])))
{
if ((token is NumberToken && char.IsNumber(s[pos]))
|| (token is SymbolToken && IsSymbolChar(s[pos], excludedSymbols) && !symbolIsOneChar)
|| (token is WordToken && !char.IsNumber(s[pos]) && !IsSymbolChar(s[pos], excludedSymbols) && !char.IsWhiteSpace(s[pos]))
|| (token is QuotedLiteralToken && s[pos] != quoteCharacter))
token.ExtendRight();
else if (token is NumberToken
&& s[pos] == decimalPoint[0]
&& pos + 1 < s.Length
&& char.IsNumber(s[pos+1])
&& !hasDP)
{
hasDP = true;
token.ExtendRight();
}
else
break;
pos++;
}
token.Previous = lastToken;
token.SetValue(s);
token.HasWhitespaceBefore = hasWhitespaceBefore;
if (token is QuotedLiteralToken) // skip final quote
pos++;
yield return token;
lastToken = token;
}
}