grammar_wp.bnf

<Program>       	::= ( <Prog_list> )
<Prog_list> 		::=  <Meth_or_fun> | <Program>  <Meth_or_fun>	
<Meth_or_fun> 		::=  <Method> | <Function>

<Function> 			::= ( fun ( <Arglist> ) <Instr_list> ) 
<Arglist> 			::=  id | id <Arglist>
<Method> 			::= ( method . number ( <Arglist> ) <Instr_list> )
 
<Instr_list> 		::=  <Instr> | ( <Instr_list_np> ) 
<Instr_list_np> 	::=  <Instr> | <Instr> <Instr_list_np>
<Instr> 			::=  <Conditional> | <While_block> | <Call> | ( return <Expr> ) 

<Conditional> 		::= ( if <Cond> <instr_list> <instr_list>  ) |  ( if <Cond> <instr_list> )

<While_block> 		::= ( while  <Cond> <Instr_list>  ) 
<call> 				::=  <User_call> | <Method_call> | <Builtin_call> 
<Builtin_call> 		::=  <Assignment> | <Read_call> | <Write_call> | <Arithmetic_call>
<Assignment> 		::= ( set id <Expr> ) | ( set id . number <Expr> ) | ( set this . number <Expr> )
<Read_call>  		::= ( read )
<Write_call> 		::= ( 'write' <Expr> )
<Arithmetic_call> 	::=  <Binary> | <Unary>
<Binary> 			::= ( <Bin_id> <Expr> <Expr>  )
<Unary>  			::= ( <Un_id> <Expr>  )
<User_call>  		::= ( id  <Expr_list_np> ) | ( id ) 
<Expr_list_np> 		::=  <Expr> | <Expr> <Expr_list_np>
<Method_call>  		::= ( id . id <Expr_list_np>  ) |  ( id . id )   
<Method_call>  		::= ( super . id  <Expr_list_np>  ) | ( super . id  )
<Method_call>  	 	::= ( this . id  <Expr_list_np>  ) | ( this . id  )
<Expr> 				::=  <Instr>  | number | null | true | false | this | id | id . number | this . number

<Cond>          	::= <Rel> | ( <Log_bin_op> <Cond> <Cond> ) | ( <Log_un_op> <Cond> <Cond> )
<Rel>				::= ( <Rel_op> <Expr> <Expr> ) 
<Rel_op>			::= <= | >= | > |  < | =
<Log_bin_op>		::= and | or
<Log_un_op>			::= !
<Bin_id> 			::= + | - | * | / | %
<Un_id>				::= neg