/*********************************************************************
 Grammar for programs in the Levi language
 ********************************************************************/
program         ::= globals

globals         ::= globals decl
                | /* epsilon */

decl		::= varDecl SEMICOL
       		 |  fnDecl

varDecl         ::= name COLON type
       		 |  name COLON type ASSIGN initializer

type            ::= datatype
                 |  IMMUTABLE datatype

datatype        ::= primtype LBRACKET INTLITERAL RBRACKET
                 |  primtype

primType        ::= INT
                 |  BOOL
                 |  FILE
                 |  VOID

fnDecl          ::= name COLON LPAREN maybeformals RPAREN type LCURLY stmtList RCURLY

maybeformals   ::= formalsList
                 |  /* epsilon */

formalsList     ::= formalDecl
                 |  formalsList COMMA formalDecl

formalDecl	::= name COLON type

stmtList        ::= stmtList stmt SEMICOL
                |   stmtList blockStmt
                |   /* epsilon */

blockStmt	::= WHILE LPAREN exp RPAREN LCURLY stmtList RCURLY
		| IF LPAREN exp RPAREN LCURLY stmtList RCURLY
		| IF LPAREN exp RPAREN LCURLY stmtList RCURLY ELSE LCURLY stmtList RCURLY

stmt            ::= varDecl
                | loc ASSIGN exp
                | callExp
                | loc POSTDEC
                | loc POSTINC
                | loc OUTPUT exp
                | loc INPUT loc
                | SINK name
                | RETURN exp
                | RETURN

exp             ::= exp DASH exp
                | exp CROSS exp
                | exp STAR exp
                | exp SLASH exp
                | exp AND exp
                | exp OR exp
                | exp EQUALS exp
                | exp NOTEQUALS exp
                | exp GREATER exp
                | exp GREATEREQ exp
                | exp LESS exp
                | exp LESSEQ exp
                | NOT exp
                | DASH term
                | term

callExp         ::=  loc LPAREN RPAREN   // fn call with no args
                | loc LPAREN actualsList RPAREN  // with args

actualsList     ::= exp
                | actualsList COMMA exp
                
term            ::= loc
                | literal
                | THRASH
                | LPAREN exp RPAREN
                | callExp

literal 	: INTLITERAL
                | STRINGLITERAL
                | TRUE
                | FALSE

litList		: literal
		| literal COMMA litList

initializer	: literal
		| LBRACKET litList RBRACKET

loc		::= name
		| loc LBRACKET exp RBRACKET

name           ::= ID