initial grammar for Unicorn

gistfile1.txt

file_input: stmt_list ENDMARKER

stmt_list: (NEWLINE | stmt)*

stmt: simple_stmt | compound_stmt

simple_stmt: print_stmt | assignment

print_stmt: 'show' (atom)+

atom: ( NAME | NUMBER | STRING+ )

compound_stmt: if_stmt | loop_stmt 

if_stmt: is_stmt ( 'or' is_stmt)* [otherwise_stmt] 'end'

if_stmt: 'is' test '?' then_stmt
  ('or' test '?' then_stmt )*
	[otherwise_stmt]
	'end'

then_stmt: NEWLINE  'then' ':' (NEWLINE | stmt)*

test: not_test

not_test: 'not' not_test | comparison

comparison: expr [comp_op expr]

comp_op: '<'|'>'|'='|'>='|'<='|'=/='|!='

expr: term (('+'|'-') term)*

term: factor (('*'|'/'|'%'|'//') factor)*

factor: ('+'|'-') factor | atom

otherwise_stmt: 'otherwise' ':' (NEWLINE | stmt)* 'end'

assignment: NAME '<-' expr

assignment_list: (assignment NEWLINE | NEWLINE)*

loop_stmt: 'loop' NAME ':' NEWLINE start_stmt
			stmt_list 'end'

start_stmt: 'starting' 'with' assignemnt_list 'end'