[−][src]Function rust_lisp::utils::require_int_parameter
pub fn require_int_parameter(
func_name: &str,
args: &Vec<Value>,
index: usize
) -> Result<i32, RuntimeError>
Given a Value
assumed to be a Value::List()
, grab the item at index
,
assumed to be a Value::Int()
, and return its inner i32. Err if any part
of this fails.