grammar.txt

Program : DeclList

DeclList : DeclList Decl
	     | Decl

Decl : VariableDecl 
     | FunctionDecl 
     | ClassDecl 
     | InterfaceDecl

VariableDecl : Variable ';'

Variable : Type ident

Type : int 
	 | 'double'
	 | 'bool'
	 | 'string'
	 | 'void'
	 | ident 
	 | Type[]



InterfaceDecl : 'interface' ident '{' PrototypeList '}'

PrototypeList : Prototype PrototypeList
			  | EPSILON

Prototype : Type ident ( ParamsList ) ; | EPSILON

ParamsList : Param AParam
		   | EPSILON

AParam : ',' Param AParam
       | EPSILON



FunctionDec	l : Type ident ( ParamsList ) StmtBlock 

StmtBlock : '{' VariableDeclList StmtList '}'

VariableDeclList : VariableDecl VariableDeclList
                 | EPSILON

StmtList : Stmt StmtList
         | EPSLION

Stmt : <Expr>; 
				| IfStmt | WhileStmt | ForStmt | BreakStmt | ReturnStmt | PrintStmt | StmtBlock



ClassDecl ::= class ident <extends ident> <implements ident+ ,> { Field∗ }
Field ::= VariableDecl | FunctionDecl

IfStmt ::= if ( Expr ) Stmt <else Stmt>
WhileStmt  while ( Expr ) Stmt
ForStmt ::= for ( <Expr>; Expr ; <Expr>) Stmt

ReturnStmt 	: 'return' Expr ';'
						| 'return' ';'

BreakStmt ::= break ;
PrintStmt ::= Print ( Expr+ , ) ;
Expr ::= LValue = Expr 
					| Constant 
					| LValue 
					| this 
					| Call 
					| ( Expr ) 
					| Expr + Expr 
					| Expr - Expr 
					| Expr * Expr 
					| Expr / Expr 
					| Expr % Expr 
					| - Expr 
					| Expr < Expr 
					| Expr <= Expr 
					| Expr > Expr 
					| Expr >= Expr 
					| Expr == Expr 
					| Expr != Expr 
					| Expr && Expr 
					| Expr || Expr 
					| ! Expr 
					| ReadInteger ( ) | ReadLine ( ) | New ( ident ) | NewArray ( Expr , Type )
LValue ::= ident | Expr . ident | Expr [ Expr ]
Call ::= ident ( Actuals ) | Expr . ident ( Actuals )
Actuals ::= Expr+ , |
Constant 	: intConstant 
					| doubleConstant
					| boolConstant
					| stringConstant
					| null