antlr/runtime/CSharp/Antlr4.Runtime/ITokenSource.cs

111 lines
4.6 KiB
C#

/*
* [The "BSD license"]
* Copyright (c) 2013 Terence Parr
* Copyright (c) 2013 Sam Harwell
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
using Antlr4.Runtime;
using Sharpen;
namespace Antlr4.Runtime
{
/// <summary>
/// A source of tokens must provide a sequence of tokens via nextToken()
/// and also must reveal it's source of characters; CommonToken's text is
/// computed from a CharStream; it only store indices into the char stream.
/// </summary>
/// <remarks>
/// A source of tokens must provide a sequence of tokens via nextToken()
/// and also must reveal it's source of characters; CommonToken's text is
/// computed from a CharStream; it only store indices into the char stream.
/// Errors from the lexer are never passed to the parser. Either you want
/// to keep going or you do not upon token recognition error. If you do not
/// want to continue lexing then you do not want to continue parsing. Just
/// throw an exception not under RecognitionException and Java will naturally
/// toss you all the way out of the recognizers. If you want to continue
/// lexing then you should not throw an exception to the parser--it has already
/// requested a token. Keep lexing until you get a valid one. Just report
/// errors and keep going, looking for a valid token.
/// </remarks>
public interface ITokenSource
{
/// <summary>Return a Token object from your input stream (usually a CharStream).</summary>
/// <remarks>
/// Return a Token object from your input stream (usually a CharStream).
/// Do not fail/return upon lexing error; keep chewing on the characters
/// until you get a good one; errors are not passed through to the parser.
/// </remarks>
IToken NextToken();
int Line
{
get;
}
int Column
{
get;
}
/// <summary>
/// From what character stream was this token created? You don't have to
/// implement but it's nice to know where a Token comes from if you have
/// include files etc...
/// </summary>
/// <remarks>
/// From what character stream was this token created? You don't have to
/// implement but it's nice to know where a Token comes from if you have
/// include files etc... on the input.
/// </remarks>
ICharStream InputStream
{
get;
}
/// <summary>
/// Where are you getting tokens from? normally the implication will simply
/// ask lexers input stream.
/// </summary>
/// <remarks>
/// Where are you getting tokens from? normally the implication will simply
/// ask lexers input stream.
/// </remarks>
string SourceName
{
get;
}
/// <summary>Gets the factory used for constructing tokens.</summary>
/// <remarks>Gets the factory used for constructing tokens.</remarks>
/// <summary>Optional method that lets users set factory in lexer or other source</summary>
ITokenFactory TokenFactory
{
get;
set;
}
}
}