grammar.txt

ws  -> white space
nl  -> new line
eof -> end of file symbol

statements : basic | simple | compound
	basic :
		assign

	simple : 
		  print 
		| plot
		| if 
		| for 

	compound :
		  func
		| class

assign :
	  'var'  word '='  (    number 
										| word
										| identifier word
										| var_ref )  (nl | eof)

print :
	  'print'  word  (nl | eof)
	| 'print'  '@'  var_ref  (nl | eof)
	| 'print'  'string' (word*1+)  (nl | eof)
	| 'print'  'eval' mexpr  (nl | eof)

if :
	'if'  statement  ('=' | '>' | '<')  statement (nl | eof)

for :
	'for'  number  'times'  ':'  print (nl | eof)

plot :
	'plot'  (number  ','  number)  'x-'  word  
	(number  ','  number)  'y-'  word 

func :
	declaration
	'func'  word  ':'  print

	with parameters
	'func'  'p'  (word*1+)  ':'  print
		'func'  'p'  word  ':'  print
		'func'  'p'  word  word  ':'  print

	call
	'call'  id

statement :
	(var_ref | number)

identifier :
	('bool' ('true' | 'false') 
	| 'string' (word*0+) 
	| '@' var_ref)

var_ref :
	('@' id
	| '@' id '[' number ']'
	| '@' id '[' number ',' number ]')