literalExpressionEvaluator binary operations with booleans

[piwonskp]

In the literalExpressionEvaluator pass, a binary expression could be calculated at compile time, even when only one argument is a literal. In the case of a boolean literal with the && operator, the following is done:

case '&&': // false && x = false
	return notNullMember ? null : false;

It is also known that if notNullMember is true, the result of the operation is the other member, and so the binaryOperation expression can be replaced by the left or right expression correspondingly. This is something that could be added.

Same thing happens for || operator

Add tests for this behaviour

[aniket2405]

"It is also known that if notNullMember is true, the result of the operation is the other member, and so the binaryOperation expression can be replaced by the left or right expression correspondingly."

In this case, we are considering the situation when one of the expression is a null. Then, if the notNullMember is true, should the function not return null itself, and not the other member? Similar case for the || operator.

[cicr99]

No, if an expression returns null that doesn't mean its value is null, it means it wasn't possible to determine its value at compilation time. Check evaluateLiteralExpression function for better understanding