def utf8.n
bend-kit-cbor@0.3.0.0 · cbor.bend:144
import bend-kit-cbor@0.3.0.0/cbor.bend as Cbor
import Base
144def utf8.n(+b0: U32, +b1: U32, +b2: U32, +b3: U32) -> Cp:
145 +x1 = (b1 .&. 63 : U32)
146 +x2 = (b2 .&. 63 : U32)
147 +x3 = (b3 .&. 63 : U32)
148 +c2 = (((b0 .&. 31) << 6n) .|. x1 : U32)
149 +c3 = ((((b0 .&. 15) << 12n) .|. (x1 << 6n)) .|. x2 : U32)
150 +c4 = (((((b0 .&. 7) << 18n) .|. (x1 << 12n)) .|. (x2 << 6n)) .|. x3 : U32)
151 +ok2 = U32.is_le(192, b0) && U32.is_lt(b0, 224) && cont(b1) && U32.is_le(128, c2)
152 +ok3 = U32.is_le(224, b0) && U32.is_lt(b0, 240) && cont(b1) && cont(b2) && U32.is_le(2048, c3) && (U32.is_lt(c3, 55296) || U32.is_lt(57343, c3))
153 +ok4 = U32.is_le(240, b0) && U32.is_lt(b0, 248) && cont(b1) && cont(b2) && cont(b3) && U32.is_le(65536, c4) && U32.is_le(c4, 1114111)
154 Bool.pick(Cp, ok2, Cp{c2, 2}, Bool.pick(Cp, ok3, Cp{c3, 3}, Bool.pick(Cp, ok4, Cp{c4, 4}, Cp{0, 0})))