mod helpers

module helpers

Element symbol and atomic number lookup.

Both lookups cover hydrogen through uranium (Z = 1..=92). Unknown inputs return a stable sentinel: symbol_to_atomic_number returns 0 for unknown symbols and atomic_number_to_symbol returns “X” for unknown atomic numbers. The same lookup is exposed to C/C++ via crate::ffi::rkr_symbol_to_z and crate::ffi::rkr_z_to_symbol so downstream tools can drop their own copies of the periodic table.

Functions

fn atomic_number_to_symbol(atomic_number: u64) -> &'static str

Returns the chemical symbol for an atomic number, or “X” if unknown.

fn symbol_to_atomic_number(symbol: &str) -> u64

Returns the atomic number for a chemical symbol, or 0 if unknown.