fn parse_finite_f64(s: &str, line: usize) -> Result<f64, ParseError>Expand description
Parse a floating-point literal, rejecting non-finite values (NaN, inf, -inf).
Non-finite values are meaningless as SC constants/parameters, and NaN in particular
breaks the parse/print round-trip because NaN != NaN: a graph carrying NaN can never
compare equal to its own re-parse. Rejecting them at parse time keeps the text format
total under round-tripping.