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Treepat is a language to recognise patterns in trees in a similar way as regular expressions recognize patterns in strings. Treepat includes analogous operators to regex union, concatenation, and closure, which are extended to the notion of trees.
// Generated from antlr/treepat/Treepat.g4 by ANTLR 4.1
package antlr.treepat;
import org.antlr.v4.runtime.Lexer;
import org.antlr.v4.runtime.CharStream;
import org.antlr.v4.runtime.Token;
import org.antlr.v4.runtime.TokenStream;
import org.antlr.v4.runtime.*;
import org.antlr.v4.runtime.atn.*;
import org.antlr.v4.runtime.dfa.DFA;
import org.antlr.v4.runtime.misc.*;
@SuppressWarnings({"all", "warnings", "unchecked", "unused", "cast"})
public class TreepatLexer extends Lexer {
protected static final DFA[] _decisionToDFA;
protected static final PredictionContextCache _sharedContextCache =
new PredictionContextCache();
public static final int
DOT=1, OR_SIGN=2, PAR_OPEN=3, PAR_CLOSE=4, NUMBER_SIGN=5, AT_SIGN=6, ASTERISK=7,
ID=8, NEWLINE=9, WS=10;
public static String[] modeNames = {
"DEFAULT_MODE"
};
public static final String[] tokenNames = {
"",
"'.'", "'|'", "'('", "')'", "'#'", "'@'", "'*'", "ID", "NEWLINE", "WS"
};
public static final String[] ruleNames = {
"DOT", "OR_SIGN", "PAR_OPEN", "PAR_CLOSE", "NUMBER_SIGN", "AT_SIGN", "ASTERISK",
"ID", "NEWLINE", "WS", "SPACES"
};
// A queue where extra tokens are pushed on (see the NEWLINE lexer rule).
private java.util.LinkedList tokens = new java.util.LinkedList<>();
// The stack that keeps track of the indentation level.
private java.util.Stack indents = new java.util.Stack<>();
// The amount of opened braces, brackets and parenthesis.
private int opened = 0;
// The most recently produced token.
private Token lastToken = null;
@Override
public void emit(Token t) {
super.setToken(t);
tokens.offer(t);
}
@Override
public Token nextToken() {
// Check if the end-of-file is ahead and there are still some DEDENTS expected.
if (_input.LA(1) == EOF && !this.indents.isEmpty()) {
// Remove any trailing EOF tokens from our buffer.
for (int i = tokens.size() - 1; i >= 0; i--) {
if (tokens.get(i).getType() == EOF) {
tokens.remove(i);
}
}
// First emit an extra line break that serves as the end of the statement.
this.emit(commonToken(TreepatParser.NEWLINE, "\n"));
// Now emit as much DEDENT tokens as needed.
while (!indents.isEmpty()) {
this.emit(createDedent());
indents.pop();
}
// Put the EOF back on the token stream.
this.emit(commonToken(TreepatParser.EOF, ""));
}
Token next = super.nextToken();
if (next.getChannel() == Token.DEFAULT_CHANNEL) {
// Keep track of the last token on the default channel.
this.lastToken = next;
}
return tokens.isEmpty() ? next : tokens.poll();
}
private Token createDedent() {
CommonToken dedent = commonToken(TreepatParser.DEDENT, "");
dedent.setLine(this.lastToken.getLine());
return dedent;
}
private CommonToken commonToken(int type, String text) {
int stop = this.getCharIndex() - 1;
int start = text.isEmpty() ? stop : stop - text.length() + 1;
return new CommonToken(this._tokenFactorySourcePair, type, DEFAULT_TOKEN_CHANNEL, start, stop);
}
// Calculates the indentation of the provided spaces, taking the
// following rules into account:
//
// "Tabs are replaced (from left to right) by one to eight spaces
// such that the total number of characters up to and including
// the replacement is a multiple of eight [...]"
//
// -- https://docs.python.org/3.1/reference/lexical_analysis.html#indentation
static int getIndentationCount(String spaces) {
int count = 0;
for (char ch : spaces.toCharArray()) {
switch (ch) {
case '\t':
count += 8 - (count % 8);
break;
default:
// A normal space char.
count++;
}
}
return count;
}
boolean atStartOfInput() {
return super.getCharPositionInLine() == 0 && super.getLine() == 1;
}
public TreepatLexer(CharStream input) {
super(input);
_interp = new LexerATNSimulator(this,_ATN,_decisionToDFA,_sharedContextCache);
}
@Override
public String getGrammarFileName() { return "Treepat.g4"; }
@Override
public String[] getTokenNames() { return tokenNames; }
@Override
public String[] getRuleNames() { return ruleNames; }
@Override
public String[] getModeNames() { return modeNames; }
@Override
public ATN getATN() { return _ATN; }
@Override
public void action(RuleContext _localctx, int ruleIndex, int actionIndex) {
switch (ruleIndex) {
case 8: NEWLINE_action((RuleContext)_localctx, actionIndex); break;
case 9: WS_action((RuleContext)_localctx, actionIndex); break;
}
}
private void NEWLINE_action(RuleContext _localctx, int actionIndex) {
switch (actionIndex) {
case 0:
String newLine = getText().replaceAll("[^\r\n]+", "");
String spaces = getText().replaceAll("[\r\n]+", "");
int next = _input.LA(1);
if (opened > 0 || next == '\r' || next == '\n' || next == '#') {
// If we're inside a list or on a blank line, ignore all indents,
// dedents and line breaks.
skip();
}
else {
emit(commonToken(NEWLINE, newLine));
int indent = getIndentationCount(spaces);
int previous = indents.isEmpty() ? 0 : indents.peek();
if (indent == previous) {
// skip indents of the same size as the present indent-size
skip();
}
else if (indent > previous) {
indents.push(indent);
emit(commonToken(TreepatParser.INDENT, spaces));
}
else {
// Possibly emit more than 1 DEDENT token.
while(!indents.isEmpty() && indents.peek() > indent) {
this.emit(createDedent());
indents.pop();
}
}
}
break;
}
}
private void WS_action(RuleContext _localctx, int actionIndex) {
switch (actionIndex) {
case 1: skip(); break;
}
}
@Override
public boolean sempred(RuleContext _localctx, int ruleIndex, int predIndex) {
switch (ruleIndex) {
case 8: return NEWLINE_sempred((RuleContext)_localctx, predIndex);
}
return true;
}
private boolean NEWLINE_sempred(RuleContext _localctx, int predIndex) {
switch (predIndex) {
case 0: return atStartOfInput();
}
return true;
}
public static final String _serializedATN =
"\3\uacf5\uee8c\u4f5d\u8b0d\u4a45\u78bd\u1b2f\u3378\2\fJ\b\1\4\2\t\2\4"+
"\3\t\3\4\4\t\4\4\5\t\5\4\6\t\6\4\7\t\7\4\b\t\b\4\t\t\t\4\n\t\n\4\13\t"+
"\13\4\f\t\f\3\2\3\2\3\3\3\3\3\4\3\4\3\5\3\5\3\6\3\6\3\7\3\7\3\b\3\b\3"+
"\t\3\t\7\t*\n\t\f\t\16\t-\13\t\3\n\3\n\3\n\5\n\62\n\n\3\n\3\n\5\n\66\n"+
"\n\3\n\5\n9\n\n\5\n;\n\n\3\n\3\n\3\13\6\13@\n\13\r\13\16\13A\3\13\3\13"+
"\3\f\6\fG\n\f\r\f\16\fH\2\r\3\3\1\5\4\1\7\5\1\t\6\1\13\7\1\r\b\1\17\t"+
"\1\21\n\1\23\13\2\25\f\3\27\2\1\3\2\5\4\2C\\c|\6\2\62;C\\aac|\4\2\13\13"+
"\"\"O\2\3\3\2\2\2\2\5\3\2\2\2\2\7\3\2\2\2\2\t\3\2\2\2\2\13\3\2\2\2\2\r"+
"\3\2\2\2\2\17\3\2\2\2\2\21\3\2\2\2\2\23\3\2\2\2\2\25\3\2\2\2\3\31\3\2"+
"\2\2\5\33\3\2\2\2\7\35\3\2\2\2\t\37\3\2\2\2\13!\3\2\2\2\r#\3\2\2\2\17"+
"%\3\2\2\2\21\'\3\2\2\2\23:\3\2\2\2\25?\3\2\2\2\27F\3\2\2\2\31\32\7\60"+
"\2\2\32\4\3\2\2\2\33\34\7~\2\2\34\6\3\2\2\2\35\36\7*\2\2\36\b\3\2\2\2"+
"\37 \7+\2\2 \n\3\2\2\2!\"\7%\2\2\"\f\3\2\2\2#$\7B\2\2$\16\3\2\2\2%&\7"+
",\2\2&\20\3\2\2\2\'+\t\2\2\2(*\t\3\2\2)(\3\2\2\2*-\3\2\2\2+)\3\2\2\2+"+
",\3\2\2\2,\22\3\2\2\2-+\3\2\2\2./\6\n\2\2/;\5\27\f\2\60\62\7\17\2\2\61"+
"\60\3\2\2\2\61\62\3\2\2\2\62\63\3\2\2\2\63\66\7\f\2\2\64\66\4\16\17\2"+
"\65\61\3\2\2\2\65\64\3\2\2\2\668\3\2\2\2\679\5\27\f\28\67\3\2\2\289\3"+
"\2\2\29;\3\2\2\2:.\3\2\2\2:\65\3\2\2\2;<\3\2\2\2<=\b\n\2\2=\24\3\2\2\2"+
">@\5\27\f\2?>\3\2\2\2@A\3\2\2\2A?\3\2\2\2AB\3\2\2\2BC\3\2\2\2CD\b\13\3"+
"\2D\26\3\2\2\2EG\t\4\2\2FE\3\2\2\2GH\3\2\2\2HF\3\2\2\2HI\3\2\2\2I\30\3"+
"\2\2\2\n\2+\61\658:AH";
public static final ATN _ATN =
ATNSimulator.deserialize(_serializedATN.toCharArray());
static {
_decisionToDFA = new DFA[_ATN.getNumberOfDecisions()];
for (int i = 0; i < _ATN.getNumberOfDecisions(); i++) {
_decisionToDFA[i] = new DFA(_ATN.getDecisionState(i), i);
}
}
}