Seqair-Types — Phred Quality Score

Sources: Phred quality scores are defined in [SAM1] section 1.4 (QUAL field, Phred+33 encoding). The Phred newtype wraps the mathematical definition: Q = -10 log10(P). See References.

Construction

types.phred.non_negative

Phred scores MUST be non-negative. from_phred MUST accept only u8 values (0..=255), making negative inputs unrepresentable at the type level.

Integer conversion

types.phred.as_int_clamp

as_int MUST clamp the result to the range [0, 99]. Values less than or equal to zero (including negative results from floating-point arithmetic) MUST return 0. NaN MUST return 0.