PreprocessingLexer.java

PreprocessingLexer.java

package glslplugin.lang.scanner;

import com.intellij.lang.ForeignLeafType;
import com.intellij.lang.TokenWrapper;
import com.intellij.lexer.Lexer;
import com.intellij.lexer.LookAheadLexer;
import com.intellij.psi.tree.IElementType;
import com.intellij.util.containers.ImmutableUserMap;
import org.jetbrains.annotations.NotNull;

import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import static glslplugin.lang.elements.GLSLTokenTypes.IDENTIFIER;

/**
 * Created by abigail on 12/07/15.
 */
public class PreprocessingLexer extends LookAheadLexer {
    public PreprocessingLexer(Lexer delegate) {
        super(delegate);
    }

    Map<String, List<IElementType>> definitions;

    @Override
    public void start(CharSequence buffer, int startOffset, int endOffset, int initialState) {
        super.start(buffer, startOffset, endOffset, initialState);
        definitions = new HashMap<>();
        definitions.put("hello", Arrays.asList(new ForeignLeafType(IDENTIFIER, "salut")));
    }

    @Override
    public void advance() {
        if (definitions.containsKey(getTokenText())) {
            definitions.get(getTokenText()).forEach(this::addToken);
        }
        super.advance();
    }

    @NotNull
    @Override
    public CharSequence getTokenSequence() {
        if (getTokenType() instanceof TokenWrapper) {
            return ((TokenWrapper) getTokenType()).getValue();
        }
        return super.getTokenSequence();
    }

    @NotNull
    @Override
    public PreprocessingLexerPosition getCurrentPosition() {
        return new PreprocessingLexerPosition(this, ImmutableUserMap.EMPTY);
    }

    @Override
    protected void restore(LookAheadLexerPosition position) {
        super.restore(position);
        assert position instanceof PreprocessingLexerPosition;
        definitions = ((PreprocessingLexerPosition) position).definitions;
    }

    protected static class PreprocessingLexerPosition extends LookAheadLexerPosition {
        final Map<String, List<IElementType>> definitions;
        public PreprocessingLexerPosition(final PreprocessingLexer lexer, ImmutableUserMap map) {
            super(lexer, map);
            definitions = new HashMap<>(lexer.definitions);
        }
    }


}