/// <summary>
/// Gets the tokens in the match context by executing a different lexer
/// </summary>
/// <param name="context">The context of the current lexing process</param>
/// <param name="value">The string to lex</param>
/// <returns></returns>
public override IEnumerable <Token> GetTokens(RegexLexerContext context, string value)
{
var tokens = Lexer.GetTokens(value);
context.Position += value.Length;
return(tokens);
}
/// <summary>
/// Processes a match group and yields a single token for the vale
/// </summary>
/// <param name="context">The context of the lexer</param>
/// <param name="value">The group value that should be turned into a token</param>
/// <returns></returns>
public override IEnumerable <Token> GetTokens(RegexLexerContext context, string value)
{
yield return(new Token(context.Position, Type, value));
context.Position += value.Length;
}
/// <summary> /// Gets the tokens for a matched group value /// </summary> /// <param name="context">The lexer context</param> /// <param name="value">The matched group value to process</param> /// <returns></returns> public abstract IEnumerable <Token> GetTokens(RegexLexerContext context, string value);
/// <summary>
/// When overridden in a child class, gets all the <see cref="Token"/>s for the given string
/// </summary>
/// <param name="text">The string to tokenize</param>
/// <returns>A sequence of <see cref="Token"/> structs</returns>
protected override IEnumerable <Token> GetTokensUnprocessed(string text)
{
var rules = GetStateRules();
int pos = 0;
var stateStack = new Stack <string>(50);
stateStack.Push("root");
var currentStateRules = rules[stateStack.Peek()];
string nf = "";
int nfpos = -1;
while (true)
{
bool found = false;
foreach (var rule in currentStateRules)
{
var m = rule.Regex.Match(text, pos);
if (m.Success)
{
if (nfpos != -1 && (!String.IsNullOrEmpty(nf.Trim())))
{
yield return(new Token(nfpos, TokenTypes.Token, nf.ToString()));
nfpos = -1;
nf = "";
}
var context = new RegexLexerContext(pos, m, stateStack, rule.TokenType);
//Debug.Assert(m.Index == pos, $"Regex \"{rule.Regex}\" should have matched at position {pos} but matched at {m.Index}");
var tokens = rule.Action.Execute(context);
foreach (var token in tokens)
{
yield return(token);
}
pos = context.Position;
currentStateRules = rules[stateStack.Peek()];
found = true;
break;
}
}
if (!found)
{
if (pos >= text.Length)
{
break;
}
if (text[pos] == '\n')
{
stateStack.Clear();
stateStack.Push("root");
currentStateRules = rules["root"];
yield return(new Token(pos, TokenTypes.Text, "\n"));
pos++;
continue;
}
//yield return new Token(pos, TokenTypes.Error, text[pos].ToString());
nf += text[pos].ToString();
if (nfpos == -1)
{
nfpos = pos;
}
pos++;
}
}
}
