eatBoolean method
Attempts to parse and consume a boolean value ('true' or 'false').
Returns true if 'true' is found, false if 'false' is found, or null if neither is found at the current position.
Implementation
bool? eatBoolean() {
if (eatString('true')) {
return true;
} else if (eatString('false')) {
return false;
}
return null;
}