NetBeans平台语言和ANTLR词法

Question

如何使NetBeans LexerInput适应于ANTLR的CharStream。我有下一个实现，但工作不太好。我想通过ANTLR词法分析器向NetBeans平台添加一种新语言。

Lexer只发出EOF，但令牌类型是ok的，我不明白。

import java.util.ArrayList;
import java.util.List;
import org.antlr.v4.runtime.CharStream;
import org.antlr.v4.runtime.misc.Interval;
import org.netbeans.spi.lexer.LexerInput;
/**
 * @author jonny
 */
public class AntlrCharStream implements CharStream {

    private class CharStreamState {
        int index;
        int line;
        int charPositionInLine;
    }
    private int line = 1;
    private int charPositionInLine = 0;
    private LexerInput input;
    private String name;
    private int index = 0;
    private List<CharStreamState> markers;
    private int markDepth = 0;
    private int lastMarker;
    public AntlrCharStream(LexerInput input, String name) {
        this.input = input;
        this.name = name;
    }
    @Override
    public String getText(Interval intrvl) {
        return input.readText().toString();
    }
    public String substring(int start, int stop) {
        throw new UnsupportedOperationException("Not supported yet.");
    }
    public int LT(int i) {
        return LA(i);
    }
    public int getLine() {
        return line;
    }
    public void setLine(int line) {
        this.line = line;
    }
    public void setCharPositionInLine(int pos) {
        this.charPositionInLine = pos;
    }
    public int getCharPositionInLine() {
        return charPositionInLine;
    }
    public void consume() {
        int c = input.read();
        index++;
        charPositionInLine++;
        if (c == 'n') {
            line++;
            charPositionInLine = 0;
        }
    }
    public int LA(int i) {
        if (i == 0) {
            return 0; // undefined
        }
        int c = 0;
        for (int j = 0; j < i; j++) {
            c = read();
        }
        backup(i);
        return c;
    }
    public int mark() {
        if (markers == null) {
            markers = new ArrayList<CharStreamState>();
            markers.add(null); // depth 0 means no backtracking, leave blank
        }
        markDepth++;
        CharStreamState state = null;
        if (markDepth >= markers.size()) {
            state = new CharStreamState();
            markers.add(state);
        } else {
            state = (CharStreamState) markers.get(markDepth);
        }
        state.index = index;
        state.line = line;
        state.charPositionInLine = charPositionInLine;
        lastMarker = markDepth;
        return markDepth;
    }
    public void rewind() {
        rewind(lastMarker);
    }
    public void rewind(int marker) {
        CharStreamState state = (CharStreamState) markers.get(marker);
        // restore stream state
        seek(state.index);
        line = state.line;
        charPositionInLine = state.charPositionInLine;
        release(marker);
    }
    public void release(int marker) {
        // unwind any other markers made after m and release m
        markDepth = marker;
        // release this marker
        markDepth--;
    }
    public void seek(int index) {
        if (index < this.index) {
            backup(this.index - index);
            this.index = index; // just jump; don't update stream state (line, ...)
            return;
        }
        // seek forward, consume until p hits index
        while (this.index < index) {
            consume();
        }
    }
    public int index() {
        return index;
    }
    public int size() {
        return -1; //unknown...
    }
    public String getSourceName() {
        return name;
    }
    private int read() {
        int result = input.read();
        if (result == LexerInput.EOF) {
            result = CharStream.EOF;
        }
        return result;
    }
    private void backup(int count) {
        input.backup(count);
    }
}

'[@-1,6:6='<EOF>',<1>,2:2]'
'[@-1,7:7='<EOF>',<1>,2:3]'
'[@-1,8:15='<EOF>',<9>,2:4]'
'[@-1,16:16='<EOF>',<1>,2:12]'
'[@-1,17:23='<EOF>',<8>,2:13]'
'[@-1,24:24='<EOF>',<1>,2:20]'
'[@-1,25:25='<EOF>',<2>,2:21]'
'[@-1,26:26='<EOF>',<1>,3:0]'
'[@-1,27:27='<EOF>',<1>,3:1]'
'[@-1,28:28='<EOF>',<1>,3:2]'
'[@-1,29:29='<EOF>',<1>,3:3]'
'[@-1,30:37='<EOF>',<4>,3:4]'
'[@-1,38:38='<EOF>',<1>,3:12]'
'[@-1,39:43='<EOF>',<5>,3:13]'
'[@-1,44:44='<EOF>',<1>,3:18]'
'[@-1,45:48='<EOF>',<9>,3:19]'
'[@-1,49:49='<EOF>',<1>,3:23]'
'[@-1,50:53='<EOF>',<7>,3:24]'
'[@-1,54:54='<EOF>',<1>,3:28]'
'[@-1,55:56='<EOF>',<6>,3:29]'
'[@-1,57:57='<EOF>',<2>,3:31]'
'[@-1,58:57='<EOF>',<-1>,4:32]'

Answer 1

我也在尝试使用ANTLR 4制作NetBeans插件。这是我在修改了该教程中的AntlrCharStream后得出的结论。到目前为止，这对我来说是有效的。

import org.antlr.v4.runtime.CharStream;
import org.antlr.v4.runtime.misc.Interval;
import org.netbeans.spi.lexer.LexerInput;
public class AntlrCharStream implements CharStream {
    private final LexerInput input;
    private final String name;
    private int index = 0;
    private int markDepth = 0;
    public AntlrCharStream(LexerInput input, String name) {
        this.input = input;
        this.name = name;
    }
    @Override
    public String getText(Interval interval) {
        throw new UnsupportedOperationException("Not supported.");
    }
    @Override
    public void consume() {
        int character = read();
        if (character == EOF) {
            backup(1);
            throw new IllegalStateException("Attempting to consume EOF");
        }
        index++;
    }
    @Override
    public int LA(int lookaheadAmount) {
        if (lookaheadAmount < 0) {
            return lookBack(-lookaheadAmount);
        } else if (lookaheadAmount > 0) {
            return lookAhead(lookaheadAmount);
        } else {
            return 0; //Behaviour is undefined when lookaheadAmount == 0
        }
    }
    private int lookBack(int amount) {
        backup(amount);
        int character = read();
        for (int i = 1; i < amount; i++) {
            read();
        }
        return character;
    }
    private int lookAhead(int amount) {
        int character = 0;
        for (int i = 0; i < amount; i++) {
            character = read();
        }
        backup(amount);
        return character;
    }
    @Override
    public int mark() {
        return ++markDepth;
    }
    @Override
    public void release(int marker) {
        // unwind any other markers made after m and release m
        markDepth = marker;
        // release this marker
        markDepth--;
    }
    @Override
    public void seek(int index) {
        if (index < 0) {
            throw new IllegalArgumentException(String.format("Invalid index (%s < 0)", index));
        }
        if (index < this.index) {
            backup(this.index - index);
            this.index = index;
            return;
        }
        // seek forward, consume until p hits index
        while (this.index < index) {
            consume();
        }
    }
    @Override
    public int index() {
        return index;
    }
    @Override
    public int size() {
        throw new UnsupportedOperationException("Stream size unknown");
    }
    @Override
    public String getSourceName() {
        return name;
    }
    private int read() {
        int result = input.read();
        if (result == LexerInput.EOF) {
            return EOF;
        } else {
            return result;
        }
    }
    private void backup(int count) {
        input.backup(count);
    }
}

Answer 2

我已经修改了Daniel提出的实现来实现getText函数。我还修改了索引位置的跟踪方式。到目前为止，它对我来说是有效的，但因为我没有时间了，它仍然需要适当的测试。

import org.antlr.v4.runtime.CharStream;
import org.antlr.v4.runtime.misc.Interval;
import org.netbeans.spi.lexer.LexerInput;
public class AntlrCharStream implements CharStream {
  private final LexerInput input;
  private final String name;
  private int index = 0;
  private int markDepth = 0;
  public AntlrCharStream(LexerInput input, String name) {
    this.input = input;
    this.name = name;
  }
  @Override
  public String getText(Interval interval) {
    int start = interval.a;
    int stop = interval.b;
    if (start < 0 || stop < start) {
      return "";
    }
    final int pos = this.index;
    final int length = interval.length();
    final char[] data = new char[length];
    seek(interval.a);
    int r = 0;
    while (r < length) {
      final int character = read();
      if (character == EOF) {
        break;
      }
      data[r] = (char) character;
      r++;
    }
    seek(pos);
    if (r > 0) {
      return new String(data, 0, r);
    } else {
      return "";
    }
  }
  @Override
  public void consume() {
    int character = read();
    if (character == EOF) {
      backup(1);
      throw new IllegalStateException("Attempting to consume EOF");
    }
  }
  @Override
  public int LA(int lookaheadAmount) {
    if (lookaheadAmount < 0) {
      return lookBack(-lookaheadAmount);
    } else if (lookaheadAmount > 0) {
      return lookAhead(lookaheadAmount);
    } else {
      return 0; //Behaviour is undefined when lookaheadAmount == 0
    }
  }
  private int lookBack(int amount) {
    backup(amount);
    int character = read();
    for (int i = 1; i < amount; i++) {
      read();
    }
    return character;
  }
  private int lookAhead(int amount) {
    int character = 0;
    for (int i = 0; i < amount; i++) {
      character = read();
    }
    backup(amount);
    return character;
  }
  @Override
  public int mark() {
    return ++markDepth;
  }
  @Override
  public void release(int marker) {
    // unwind any other markers made after m and release m
    markDepth = marker;
    // release this marker
    markDepth--;
  }
  @Override
  public void seek(int index) {
    if (index < 0) {
      throw new IllegalArgumentException(String.format("Invalid index (%s < 0)", index));
    }
    if (index < this.index) {
      backup(this.index - index);
      return;
    }
    // seek forward, consume until p hits index
    while (this.index < index) {
      consume();
    }
  }
  @Override
  public int index() {
    return index;
  }
  @Override
  public int size() {
    return -1; //unknown...
  }
  @Override
  public String getSourceName() {
    return name;
  }
  private int read() {
    int result = input.read();
    index++;
    if (result == LexerInput.EOF) {
      return EOF;
    } else {
      return result;
    }
  }
  private void backup(int count) {
    input.backup(count);
    index -= count;
  }
}

我在:https://gist.github.com/megothss/849fb466a21793956033中创建了一个要点，以防有人想要贡献改进它。

Answer 3

google查询"antlr netbeans"显示了许多文章，尽管是v3而不是v4。例如,http://wiki.netbeans.org/New_Language_Support_Tutorial_Antlr

你是否运行了不同的查询?