编译原理虎书java版本Chapter 23

options {
  JAVA_UNICODE_ESCAPE = true;
}

PARSER_BEGIN(MiniJavaParser)
  public class MiniJavaParser {}
PARSER_END(MiniJavaParser)

// Insert a specification of a lexical analysis here.

TOKEN :
{
  < LPAREN: "(" >
| < RPAREN: ")" >
| < LSQPAREN: "[" >
| < RSQPAREN: "]" >
| < LBRACE: "{" >
| < RBRACE: "}" >
| < DOT: "." >
| < ASSIGN: "=" >
| < LT: "<" >
| < PLUS: "+" >
| < MINUS: "-" >
| < AND : "&&" >  
| < NOT : "!" >  
| < SEMICOLON: ";" >
| < PUBLIC: "public" >
| < RETURN: "return" >
| < BOOLEAN: "boolean" >  
| < CLASS: "class" >
| < INTERFACE: "interface" >
| < ELSE: "else" >
| < EXTENDS: "extends" >
| < FALSE: "false" >
| < IF: "if" >
| < WHILE: "while" >
| < INTEGER: "int" >  
| < LENGTH: "length" >
| < MAIN: "main" >
| < NEW: "new" >
| < STATIC: "static" >
| < STRING: "String" >
| < THIS: "this" >
| < TRUE: "true" >
| < PRINT: "System.out.println" >
| < VOID: "void" >        
}

TOKEN : /* LITERALS */
{
  < INTEGER_LITERAL: ( ["1"-"9"] (["0"-"9"])* | "0" ) >
}

TOKEN : /* IDENTIFIERS */
{
  < IDENTIFIER: <LETTER> (<LETTER>|<DIGIT>)* >
|
  < #LETTER:
      [
       "\u0024",
       "\u0041"-"\u005a",
       "\u005f",
       "\u0061"-"\u007a",
       "\u00c0"-"\u00d6",
       "\u00d8"-"\u00f6",
       "\u00f8"-"\u00ff",
       "\u0100"-"\u1fff",
       "\u3040"-"\u318f",
       "\u3300"-"\u337f",
       "\u3400"-"\u3d2d",
       "\u4e00"-"\u9fff",
       "\uf900"-"\ufaff"
      ]
  >
|
  < #DIGIT:
      [
       "\u0030"-"\u0039",
       "\u0660"-"\u0669",
       "\u06f0"-"\u06f9",
       "\u0966"-"\u096f",
       "\u09e6"-"\u09ef",
       "\u0a66"-"\u0a6f",
       "\u0ae6"-"\u0aef",
       "\u0b66"-"\u0b6f",
       "\u0be7"-"\u0bef",
       "\u0c66"-"\u0c6f",
       "\u0ce6"-"\u0cef",
       "\u0d66"-"\u0d6f",
       "\u0e50"-"\u0e59",
       "\u0ed0"-"\u0ed9",
       "\u1040"-"\u1049"
      ]
  >
}

SKIP :
{
  < " " >
| < "\t" >
| < "\n" >
| < "\r" >
| < "//" (~["\n"])* "\n" >
| <"/*" (~["*"])* "*" (~["/"] (~["*"])* "*")* "/">
}

// The following is a simple grammar that will allow you
// to test the generated lexer.

void Program() :
{}
{
  MainClass() (ClassDecl())*
}

void MainClass() :
{}
{
 "class" <IDENTIFIER> "{" "public" "static" "void" "main" "(" "String" "[" "]" <IDENTIFIER> "{" Statement() "}" "}"
}

void ext() :
{}
{
 ("extends"  <IDENTIFIER> )?
}

void ClassDecl() :
{}
{
 "class" <IDENTIFIER> ext()  "{" (VarDecl())* (MethodDecl())* "}"
}

void VarDecl():
{}
{ Type() <IDENTIFIER> ";"}

void MethodDecl():
{}
{"public" Type() <IDENTIFIER>
  "(" FormaList() ")"  
  "{" ( LOOKAHEAD(2) VarDecl() )* (Statement())*  "return" Exp() ";" "}"
 }

void FormaList():
{}
{(Type()  <IDENTIFIER> "FormalRest()")?}

void FormaRest():
{}
{"," Type() <IDENTIFIER>}

void Type():
{}
{<IDENTIFIER>
|"boolean"
|LOOKAHEAD(2)
 "int"
|"int" "[" "]"
}

void Statement():
{}
{"{" (Statement())* "}"
|"while" "(" Exp() ")" Statement()
|"System.out.println"  "(" Exp() ")"
|<IDENTIFIER> instat1() "=" Exp() ";"
|"if" "(" Exp() ")" Statement() inif()
}

void inif():
{}
{(LOOKAHEAD(2) "else" Statement())?}

void instat1():
{}
{("[" Exp() "]")?}

void Exp():
{}
{Expa() (LOOKAHEAD(2) (Expb()))?
}
 
void Expa():
{}
{"true"
|"false"
|<IDENTIFIER>
|"this"
|"!" Exp()
|"(" Exp() ")"
|LOOKAHEAD(2)
 "new" "int" "[" Exp() "]"
|"new" <IDENTIFIER> "(" ")"
}

void Expb():
{}
{
 op() Exp()
|"[" Exp() "]"Exp()
|LOOKAHEAD(2)
 "." "length"
|"." <IDENTIFIER>
}

void op():
{}
{"&&"
|"<"
|"+"
|"-"
|"*"}

void ExpList():
{}
{(Exp()  (ExpRest())*)?}

void ExpRest():
{}
{"," Exp()}

void Goal() :
{}
{
  ( MiniJavaToken() )*
  <EOF>
}

void MiniJavaToken():
{}
{
  "class"  |  <IDENTIFIER> | "{" | "public" | "static" | "void" |
  "main" | "(" | "String"  | "[" | "]" | ")" | "}" | "extends" | ";"
  | "return" | "," | "int" | "boolean" | "=" | "if" | "else" | "while"
  | "System.out.println" | "&&" | "<" | "+" | "-" | "*" | "." |
  "length" | <INTEGER_LITERAL> | "true" | "false" | "this" | "new" |
  "!"
}