description.txt

Tokens:

ID: [a-z][A-Za-z0-9]*
LP: '('
RP: ')'
INT_LITERAL: [0-9]+|B[0-1]+
STRING_LITERAL: ".*"
BOOL_LITERAL: True|False
INT: Int
BOOL: Bool
STRING: String
FUNC: Func
VAR: Var
ASSIGN: :=
IF: If
ELSE: Else
WHILE: While
LB: '{'
RB: '}'
OR: ||
AND: &&
NOT: !
EQ: ==
NE: /=
LE: <=
LESS: <
GE: >=
GREATER: GE
PLUS: +
MINUS: -
MULT: *
DIV: /
UNARY_MINUS: -
POW: ^

func_call: ID params
params: LP experssion_list RP
| LP void RP

func_decl: FUNC ID type_params_list -> type {statement}

type: BOOL
| INT
| STRING

type_params_list: LP (type ID)*, type ID RP | LP RP

assign_statement: ID ASSIGN expression
decl_statement: VAR Type assign_statement

if_statement:  IF LR expression RP {statement} |
IF LR expression RP {statement} else {statement}

while_statement: WHILE LR expression RP {statement}

single_statement: skip;
| expression; 
| assign_statement;
| decl_statement;
| while_statement
| if_statement


statement: single_statement statement
| single_statement

literal: INT_LITERAL
| STRING_LITERAL
| BOOL_LITERAL

value: ID
| literal
| func_call	

expression: expression1 OR expression
| expression1

expression1: experssion2 AND expression
| expression2

expression2: NOT expression3 
| expression3 

expression3: expression4 EQ expression4
| expression4 NE expression4
| expression4 LESS expression4
| expression4 LE expression4
| expression4 GREATER expression4
| expression4 GE expression4
| expression4

expression4: expression4 PLUS expression5
| expression4 MINUS expression5
| expression5

expression5: expression5 MULT expression6
| expression5 DIV expression6
| expression6

expression6: UNARY_MINUS expression7 
| expression7

expression7: expression7 POW expression8
| expression8

expression8: value
| LP expression RP
	

start: PROG 
PROG = func_decl_sequence

func_decl_sequence = func_decl
| func_dec_sequence func_decl