NewLang Programming Language

Lexical Specification

Token	Lexeme
MAIN	"start:"
SEMI	";"
COMMA	","
PIPE	"|"
VAR	"var"
INT	"integer"
REAL	"float"
STRING	"string"
BOOL	"boolean"
CHAR	"char"
VOID	"void"
DEF	"def"
OUT	"out"
FOR	"for"
IF	"if"
ELSE	"else"
WHILE	"while"
TO	"to"
LOOP	"loop"
READ	"<--"
WRITE	"-->"
WRITELN	"-->!"
LPAR	"("
RPAR	")"
LBRAC	"{"
RBRAC	"}"
COLON	":"
ASSIGN	"<<"
RETURN	"return"
ID	[$_A-Za-z][$_A-Za-z0-9]*
INTEGER_CONST	IntegerLiteral
REAL_CONST	RealLiteral
STRING_CONST	" "
CHAR_CONST	' '
TRUE	true
FALSE	false
PLUS	"+"
MINUS	"-"
TIMES	"*"
DIV	"/"
AND	"and"
OR	"or"
GT	">"
GE	">="
LT	"<"
LE	"<="
EQ	"="
NE	"!="
NOT	"not"
STR_CONCAT	"&"

Grammar Specification

Program ::= DeclList MainFunDecl DeclList ;

DeclList ::= VarDecl DeclList | FunDecl DeclList | /* empty */;

MainFunDecl ::= MAIN FunDecl;

VarDecl ::= Type IdInitList SEMI
    | VAR IdInitObblList SEMI;

Type ::= INT | BOOL | REAL | STRING | CHAR;

IdInitList ::= ID 
    | IdInitList COMMA ID
    | ID ASSIGN Expr
    | IdInitList COMMA ID ASSIGN Expr;

IdInitObblList ::= ID ASSIGN Const
    | IdInitObblList COMMA ID ASSIGN Const;

Const ::= INTEGER_CONST
        | REAL_CONST
        | TRUE 
        | FALSE
        | STRING_CONST 
        | CHAR_CONST; 

FunDecl ::= DEF ID LPAR ParamDeclList RPAR COLON TypeOrVoid Body;

Body ::= LBRAC VarDeclList StatList RBRAC
        | LBRAC VarDeclList RBRAC;

ParamDeclList ::= /*empty */
        | NonEmptyParamDeclList;

NonEmptyParamDeclList ::= ParDecl
    | NonEmptyParamDeclList PIPE ParDecl;

ParDecl ::= Type IdList
    | OUT Type IdList;

TypeOrVoid ::= Type | VOID;

VarDeclList ::= /* empty */ 
    | VarDecl VarDeclList;
    
StatList ::= Stat | Stat StatList;

Stat ::= IfStat 
    | ForStat 
    | ReadStat SEMI 
    | WriteStat SEMI 
    | AssignStat SEMI 
    | WhileStat 
    | FunCall SEMI 
    | RETURN Expr SEMI
    | RETURN SEMI;

IfStat ::= IF Expr THEN Body Else;

Else ::= /* empty */ | ELSE Body;

WhileStat ::= WHILE Expr LOOP Body;

ForStat ::= FOR ID ASSIGN INTEGER_CONST TO INTEGER_CONST LOOP Body;

ReadStat ::= IdList READ STRING_CONST
	| IdList READ;

IdList ::= ID | IdList COMMA ID;

WriteStat ::= LPAR ExprList RPAR WRITE | LPAR ExprList RPAR WRITELN;

AssignStat ::=  IdList ASSIGN ExprList;

FunCall ::= ID LPAR ExprList RPAR
	| ID LPAR RPAR;

ExprList ::= Expr | Expr COMMA ExprList;

Expr ::= TRUE
    | FALSE 
    | INTEGER_CONST 
    | REAL_CONST 
    | STRING_CONST
    | CHAR_CONST
    | ID 
    | FunCall
    | Expr PLUS Expr 
    | Expr MINUS Expr 
    | Expr TIMES Expr 
    | Expr DIV Expr 
    | Expr AND Expr 
    | Expr POW Expr 
    | Expr STR_CONCAT Expr 
    | Expr OR Expr 
    | Expr GT Expr 
    | Expr GE Expr 
    | Expr LT Expr 
    | Expr LE Expr 
	| Expr EQ Expr 
	| Expr NE Expr 
	| MINUS Expr 
	| NOT Expr 
	| LPAR Expr RPAR;

Notes