Compiler Project (Bali#) Grammar Spring 2008 - Part 1

File			-> (ClassDefinition)*
ClassDefinition		-> class name { (classMember)* }

classMember		-> public (Method)
	Method		-> type name ([type name (, type name)*]) statementBlock
	
statement		-> (ifStatement | whileLoop | expressionStatement | statementBlock | returnStatement | (my localVariableDeclaration) )
statementBlock		-> {statement*}
ifStatement		-> if(expression) statement [else statement]
whileLoop		-> while(expression) statement
returnStatement		-> return expression ;
expressionStatement	-> [expression] ;
localVariableDeclaration	-> type name [= expression] ;

expression		-> e1
e1			-> e2 (= e2)*
e2			-> e3 (|| e3)*
e3			-> e4 (&& e4)*
e4			-> e5 ((< | > | <= | =< | >= | => | == | !=) e5)*
e5			-> e6 ((+ | -) e6)*
e6			-> e7 ((* | / | %) e7)*
e7			-> (! | - | cast<type>)* e8
e8			-> literal | reference | (expression) | builtInFunction

builtInFunction		-> print(expression)
reference		-> name
literal			-> number | true | false

type			-> name

Part 1 Notes:

• Only a single class exists in each file, it is called Entry
• Only a single method exists in the Entry class, it is called main (it returns an int and has no arguments).
• The above implies that there is an implicit a no-args constructor.
• There are only local variables, (except for the built in user-input variables). Also, there is no built-in Main variable. There are also no class member variables.
• In order to make namespaces easier to implement for this part (part 1), assume the following precondition:
  Local variables (variables inside functions), will only be declared in the method's statement block and they will occur before any other statements. This means that no local variables can be declared in any nested statement blocks.
• User-input is available though the built-in user-input variables (see the full grammar's semantic section on User Input)
• Though a type may be any identifier, for this part of the assignment, the only types that are defined are: int, boolean, char (Note that void is not used in this part)

Sample Programs

Hello World (even though we don't have strings yet)

class Entry
{
	# Simple  program that returns 5
	public int main()
	{
		return (5);
	}
}