C# (CSharp) Antlr4.Runtime Namespace

This error strategy is useful in the following scenarios.

• Two-stage parsing: This error strategy allows the first stage of two-stage parsing to immediately terminate if an error is encountered, and immediately fall back to the second stage. In addition to avoiding wasted work by attempting to recover from errors here, the empty implementation of Sync(Parser) improves the performance of the first stage.
• Silent validation: When syntax errors are not being reported or logged, and the parse result is simply ignored if errors occur, the BailErrorStrategy avoids wasting work on recovering from errors when the result will be ignored either way.

myparser.setErrorHandler(new BailErrorStrategy());

This token stream ignores the value of IToken.Channel() . If your parser requires the token stream filter tokens to only those on a particular channel, such as TokenConstants.DefaultChannel or TokenConstants.HiddenChannel , use a filtering token stream such a CommonTokenStream .

This token stream provides access to all tokens by index or when calling methods like BufferedTokenStream.GetText() . The channel filtering is only used for code accessing tokens via the lookahead methods BufferedTokenStream.La(int) , Lt(int) , and Lb(int) .

By default, tokens are placed on the default channel ( TokenConstants.DefaultChannel ), but may be reassigned by using the ->channel(HIDDEN) lexer command, or by using an embedded action to call Lexer.Channel .

Note: lexer rules which use the ->skip lexer command or call Lexer.Skip() do not produce tokens at all, so input text matched by such a rule will not be available as part of the token stream, regardless of channel.

• Ambiguities: These are cases where more than one path through the grammar can match the input.
• Weak context sensitivity: These are cases where full-context prediction resolved an SLL conflict to a unique alternative which equaled the minimum alternative of the SLL conflict.
• Strong (forced) context sensitivity: These are cases where the full-context prediction resolved an SLL conflict to a unique alternative, and the minimum alternative of the SLL conflict was found to not be a truly viable alternative. Two-stage parsing cannot be used for inputs where this situation occurs.

ParserRuleContext does not include field storage for the rule index since the context classes created by the code generator override the RuleIndex() method to return the correct value for that context. Since the parser interpreter does not use the context classes generated for a parser, this class (with slightly more memory overhead per node) is used to provide equivalent functionality.

If the final token in the list is an TokenConstants.EOF token, it will be used as the EOF token for every call to NextToken() after the end of the list is reached. Otherwise, an EOF token will be created.