// Define a grammar called Hello
grammar Hello;
r  : 'hello' ID ;         // match keyword hello followed by an identifier
ID : [a-z]+ ;             // match lower-case identifiers
WS : [ \t\r\n]+ -> skip ; // skip spaces, tabs, newlines

/*
BSD License

Copyright (c) 2013, Kazunori Sakamoto
Copyright (c) 2016, Alexander Alexeev
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. Neither the NAME of Rainer Schuster nor the NAMEs of its contributors
   may be used to endorse or promote products derived from this software
   without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"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 COPYRIGHT
HOLDER OR CONTRIBUTORS 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.

This grammar file derived from:

    Lua 5.3 Reference Manual
    http://www.lua.org/manual/5.3/manual.html

    Lua 5.2 Reference Manual
    http://www.lua.org/manual/5.2/manual.html

    Lua 5.1 grammar written by Nicolai Mainiero
    http://www.antlr3.org/grammar/1178608849736/Lua.g

Tested by Kazunori Sakamoto with Test suite for Lua 5.2 (http://www.lua.org/tests/5.2/)

Tested by Alexander Alexeev with Test suite for Lua 5.3 http://www.lua.org/tests/lua-5.3.2-tests.tar.gz
*/

grammar Lua;

chunk
    : block EOF
    ;

block
    : stat* retstat?
    ;

stat
    : ';'
    | varlist '=' explist
    | functioncall
    | label
    | 'break'
    | 'goto' NAME
    | 'do' block 'end'
    | 'while' exp 'do' block 'end'
    | 'repeat' block 'until' exp
    | 'if' exp 'then' block ('elseif' exp 'then' block)* ('else' block)? 'end'
    | 'for' NAME '=' exp ',' exp (',' exp)? 'do' block 'end'
    | 'for' namelist 'in' explist 'do' block 'end'
    | 'function' funcname funcbody
    | 'local' 'function' NAME funcbody
    | 'local' attnamelist ('=' explist)?
    ;

attnamelist
    : NAME attrib (',' NAME attrib)*
    ;

attrib
    : ('<' NAME '>')?
    ;

retstat
    : 'return' explist? ';'?
    ;

label
    : '::' NAME '::'
    ;

funcname
    : NAME ('.' NAME)* (':' NAME)?
    ;

varlist
    : var_ (',' var_)*
    ;

namelist
    : NAME (',' NAME)*
    ;

explist
    : exp (',' exp)*
    ;

exp
    : 'nil' | 'false' | 'true'
    | number
    | string
    | '...'
    | functiondef
    | prefixexp
    | tableconstructor
    | <assoc=right> exp operatorPower exp
    | operatorUnary exp
    | exp operatorMulDivMod exp
    | exp operatorAddSub exp
    | <assoc=right> exp operatorStrcat exp
    | exp operatorComparison exp
    | exp operatorAnd exp
    | exp operatorOr exp
    | exp operatorBitwise exp
    ;

prefixexp
    : varOrExp nameAndArgs*
    ;

functioncall
    : varOrExp nameAndArgs+
    ;

varOrExp
    : var_ | '(' exp ')'
    ;

var_
    : (NAME | '(' exp ')' varSuffix) varSuffix*
    ;

varSuffix
    : nameAndArgs* ('[' exp ']' | '.' NAME)
    ;

nameAndArgs
    : (':' NAME)? args
    ;

/*
var_
    : NAME | prefixexp '[' exp ']' | prefixexp '.' NAME
    ;

prefixexp
    : var_ | functioncall | '(' exp ')'
    ;

functioncall
    : prefixexp args | prefixexp ':' NAME args
    ;
*/

args
    : '(' explist? ')' | tableconstructor | string
    ;

functiondef
    : 'function' funcbody
    ;

funcbody
    : '(' parlist? ')' block 'end'
    ;

parlist
    : namelist (',' '...')? | '...'
    ;

tableconstructor
    : '{' fieldlist? '}'
    ;

fieldlist
    : field (fieldsep field)* fieldsep?
    ;

field
    : '[' exp ']' '=' exp | NAME '=' exp | exp
    ;

fieldsep
    : ',' | ';'
    ;

operatorOr
	: 'or';

operatorAnd
	: 'and';

operatorComparison
	: '<' | '>' | '<=' | '>=' | '~=' | '==';

operatorStrcat
	: '..';

operatorAddSub
	: '+' | '-';

operatorMulDivMod
	: '*' | '/' | '%' | '//';

operatorBitwise
	: '&' | '|' | '~' | '<<' | '>>';

operatorUnary
    : 'not' | '#' | '-' | '~';

operatorPower
    : '^';

number
    : INT | HEX | FLOAT | HEX_FLOAT
    ;

string
    : NORMALSTRING | CHARSTRING | LONGSTRING
    ;

// LEXER

NAME
    : [a-zA-Z_][a-zA-Z_0-9]*
    ;

NORMALSTRING
    : '"' ( EscapeSequence | ~('\\'|'"') )* '"'
    ;

CHARSTRING
    : '\'' ( EscapeSequence | ~('\''|'\\') )* '\''
    ;

LONGSTRING
    : '[' NESTED_STR ']'
    ;

fragment
NESTED_STR
    : '=' NESTED_STR '='
    | '[' .*? ']'
    ;

INT
    : Digit+
    ;

HEX
    : '0' [xX] HexDigit+
    ;

FLOAT
    : Digit+ '.' Digit* ExponentPart?
    | '.' Digit+ ExponentPart?
    | Digit+ ExponentPart
    ;

HEX_FLOAT
    : '0' [xX] HexDigit+ '.' HexDigit* HexExponentPart?
    | '0' [xX] '.' HexDigit+ HexExponentPart?
    | '0' [xX] HexDigit+ HexExponentPart
    ;

fragment
ExponentPart
    : [eE] [+-]? Digit+
    ;

fragment
HexExponentPart
    : [pP] [+-]? Digit+
    ;

fragment
EscapeSequence
    : '\\' [abfnrtvz"'\\]
    | '\\' '\r'? '\n'
    | DecimalEscape
    | HexEscape
    | UtfEscape
    ;

fragment
DecimalEscape
    : '\\' Digit
    | '\\' Digit Digit
    | '\\' [0-2] Digit Digit
    ;

fragment
HexEscape
    : '\\' 'x' HexDigit HexDigit
    ;

fragment
UtfEscape
    : '\\' 'u{' HexDigit+ '}'
    ;

fragment
Digit
    : [0-9]
    ;

fragment
HexDigit
    : [0-9a-fA-F]
    ;

COMMENT
    : '--[' NESTED_STR ']' -> channel(HIDDEN)
    ;

LINE_COMMENT
    : '--'
    (                                               // --
    | '[' '='*                                      // --[==
    | '[' '='* ~('='|'['|'\r'|'\n') ~('\r'|'\n')*   // --[==AA
    | ~('['|'\r'|'\n') ~('\r'|'\n')*                // --AAA
    ) ('\r\n'|'\r'|'\n'|EOF)
    -> channel(HIDDEN)
    ;

WS
    : [ \t\u000C\r\n]+ -> skip
    ;

SHEBANG
    : '#' '!' ~('\n'|'\r')* -> channel(HIDDEN)
    ;

<dependencies>
    <dependency>
        <groupId>org.antlr</groupId>
        <artifactId>antlr4-runtime</artifactId>
        <version>${antlr.version}</version>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.antlr</groupId>
            <artifactId>antlr4-maven-plugin</artifactId>
            <version>${antlr.version}</version>
            <configuration>
                <visitor>true</visitor>
                <listener>true</listener>
            </configuration>
            <executions>
                <execution>
                    <goals>
                        <goal>antlr4</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

<properties>
    <!-- https://mvnrepository.com/artifact/org.antlr/antlr4-runtime -->
    <!-- Antlr4 4.9.3 is the last version compatible with Java 8 -->
    <antlr.version>4.9.3</antlr.version>
</properties>

package com.baeldung.antlr.lua.model;

/**
 * 語法錯誤
 *
 * @author duhongming
 * @see
 * @since 1.0.0
 */
public class SyntaxErrorEntry {
    private Integer lineNum;
    private String errorInfo;

    public Integer getLineNum() {
        return lineNum;
    }

    public void setLineNum(Integer lineNum) {
        this.lineNum = lineNum;
    }

    public String getErrorInfo() {
        return errorInfo;
    }

    public void setErrorInfo(String errorInfo) {
        this.errorInfo = errorInfo;
    }
}

package com.baeldung.antlr.lua.model;

import java.util.LinkedList;
import java.util.List;

/**
 * 語法錯誤報告
 *
 * @author duhongming
 * @see
 * @since 1.0.0
 */
public class SyntaxErrorReportEntry {
    private final List<SyntaxErrorEntry> syntaxErrorList = new LinkedList<>();

    public void addError(int line, int charPositionInLine, Object offendingSymbol, String msg) {
        SyntaxErrorEntry syntaxErrorEntry = new SyntaxErrorEntry();
        syntaxErrorEntry.setLineNum(line);
        syntaxErrorEntry.setErrorInfo(line + "行," + charPositionInLine + "列，" + offendingSymbol + "字符處，存在語法錯誤:" + msg);
        syntaxErrorList.add(syntaxErrorEntry);
    }

    public List<SyntaxErrorEntry> getSyntaxErrorReport() {
        return syntaxErrorList;
    }
}

package com.baeldung.antlr.lua;

import com.baeldung.antlr.LuaParser;
import com.baeldung.antlr.LuaVisitor;
import org.antlr.v4.runtime.tree.ErrorNode;
import org.antlr.v4.runtime.tree.ParseTree;
import org.antlr.v4.runtime.tree.RuleNode;
import org.antlr.v4.runtime.tree.TerminalNode;

/**
 * Lua語法遍歷器
 *
 * @author duhongming
 * @see
 * @since 1.0.0
 */
public class LuaSyntaxVisitor implements LuaVisitor<Object> {
// ctrl+O Override即可
}

package com.baeldung.antlr.lua;

import com.baeldung.antlr.lua.model.SyntaxErrorReportEntry;
import org.antlr.v4.runtime.BaseErrorListener;
import org.antlr.v4.runtime.RecognitionException;
import org.antlr.v4.runtime.Recognizer;

/**
 * 語法錯誤監(jiān)聽器
 *
 * @author duhongming
 * @see
 * @since 1.0.0
 */
public class SyntaxErrorListener extends BaseErrorListener {
    private final SyntaxErrorReportEntry reporter;

    public SyntaxErrorListener(SyntaxErrorReportEntry reporter) {
        this.reporter = reporter;
    }

    @Override
    public void syntaxError(Recognizer<?, ?> recognizer,
                            Object offendingSymbol, int line, int charPositionInLine,
                            String msg, RecognitionException e) {
        this.reporter.addError(line, charPositionInLine, offendingSymbol, msg);
    }
}

package com.baeldung.antlr;

import com.baeldung.antlr.lua.LuaSyntaxVisitor;
import com.baeldung.antlr.lua.SyntaxErrorListener;
import com.baeldung.antlr.lua.model.SyntaxErrorEntry;
import com.baeldung.antlr.lua.model.SyntaxErrorReportEntry;
import org.antlr.v4.runtime.CharStream;
import org.antlr.v4.runtime.CharStreams;
import org.antlr.v4.runtime.CommonTokenStream;
import org.junit.Test;

import java.util.List;

import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.MatcherAssert.assertThat;

public class LuaSyntaxErrorUnitTest {
    public static List<SyntaxErrorEntry> judgeLuaSyntax(String luaScript) {
        //新建一個CharStream，讀取數據
        CharStream charStreams = CharStreams.fromString(luaScript);
        //包含一個詞法分析器的定義，作用是將輸入的字符序列聚集成詞匯符號。
        LuaLexer luaLexer = new LuaLexer(charStreams);
        //新建一個詞法符號的緩沖區(qū)，用于存儲詞法分析器生成的詞法符號（Token）
        CommonTokenStream tokenStream = new CommonTokenStream(luaLexer);
        //新建一個語法分析器，用于分析詞法符號緩沖區(qū)中的詞法符號
        LuaParser luaParser = new LuaParser(tokenStream);

        SyntaxErrorReportEntry syntaxErrorReporter = new SyntaxErrorReportEntry();
        SyntaxErrorListener errorListener = new SyntaxErrorListener(syntaxErrorReporter);
        luaParser.addErrorListener(errorListener);

        LuaSyntaxVisitor luaSyntaxVisitor = new LuaSyntaxVisitor();
        luaSyntaxVisitor.visit(luaParser.chunk());
        return syntaxErrorReporter.getSyntaxErrorReport();
    }

    @Test
    public void testGood() throws Exception {
        List<SyntaxErrorEntry> errorEntryList = judgeLuaSyntax("if a~=1 then print(1) end");
        assertThat(errorEntryList.size(), is(0));
    }

    @Test
    public void testBad() throws Exception {
        //新建一個CharStream，讀取數據
        List<SyntaxErrorEntry> errorEntryList = judgeLuaSyntax("if a!=1 then print(1) end");
        assertThat(errorEntryList.size(), is(2));
    }
}