grammar Nimble;

program : funcdec* vardec* statement* ;

statement
    : 'print' expr                                                                  # print
    | 'while' expr statementblock                                                   # while
    | ('if' expr statementblock | 'if' expr statementblock 'else' statementblock)   # if
    | 'return' expr?                                                                # return
    | ID '(' ((expr ',')* expr)? ')'                                                # funccall
    | ID '=' expr                                                                   # assign
    ;

funcdec : 'func' ID '(' ((pramtr ',')* pramtr)? ')' ('->' TYPE)? '{' vardec* statement* '}';

pramtr : ID ':' TYPE ;

vardec : 'var' ID ':' TYPE ('=' expr)? ;

statementblock : '{' statement* '}' ;

expr
  : '(' expr ')'                        #bracexpr
  | op=('!' | '-') expr                 #unary
  | expr op=('*' | '/') expr            #muldiv
  | expr op=('+' | '-') expr            #addsub
  | expr op=('==' | '<' | '<=') expr    #compare
  | ID '(' ((expr ',')* expr)? ')'      #funccall
  | STRING                              #string
  | NUMBER                              #number
  | BOOL                                #bool
  | ID                                  #id
  ;

BOOL : ('true' | 'false') ;

STRING : ["]~["\r\n]*["] ;
// https://github.com/antlr/grammars-v4/blob/master/c/C.g4

TYPE : ('Int' | 'String' | 'Bool') ;

ID : [a-zA-Z_][a-zA-Z_0-9]* ;

NUMBER : [0-9]+ ;

COMMENT : '//' ~[\r\n]* -> skip ;

WS : [ \t\r\n]+ -> skip ;




//////////////////////////TEST CODE ???????????????????????????
//LEGAL STATEMENTS SECTION
print "hello"
print testVariable
// ignore this statement
a == b
var myVar : Int
var myVar: String = "hello"
if (myVar) {print "hello"}
if thing {print "hello"} else {print "goodbye"}
func myMethod() {print "stuff"}
func myMethod() -> Int {return 1}
func myMethod(garbage : Int) -> String
{
return "garbage out"
}
//TEST PROGRAM:
func countdown(from: Int, message: String) {
    var current : Int = from
    while 0 < current {
        current = displayCount(current)
    }
    print message + "\n"
}

func displayCount(c: Int) -> Int {
    print c
    print "\n"
    c = c - 1
    if c == 3 {
        print "Get ready!\n"
    }
    return c
}

var announce: String = "Liftoff"
countdown(10, announce)

//ILLEGAL MOVE SECTION
print print hello
if myVar : print "hello"
var myVar : int
var myVar = "stuff"
if thing {print "hello"} elif {print "goodbye"}
func badProgram(input) : return output