Myers.calculate_block: def of bend-edit-distance@0.2.2.0
Import: import bend-edit-distance@0.2.2.0/src/Myers.bend as Myers
Lines 94-111 of bend-edit-distance@0.2.2.0/src/Myers.bend: https://jend.leeeet.dev/read.txt?path=bend-edit-distance@0.2.2.0/src/Myers.bend&start_line=94&end_line=111

import Base

# calculateBlock / Advance_Block from Myers. Addition intentionally wraps
# at 32 bits. Xv uses the original Eq, before the negative carry is added.
def calculate_block(block: Block, +eq: U32, hin: Carry) -> Block & Carry:
  Block{+pv, +mv, score} = block
  Carry{hin_positive, +hin_negative} = hin
  +xv = U32.or(eq, mv)
  +eq_in = U32.or(eq, hin_negative)
  +xh = (U32.xor(U32.add(U32.and(eq_in, pv), pv), pv) .|. eq_in : U32)
  +ph = U32.or(mv, U32.not(U32.or(xh, pv)))
  +mh = U32.and(pv, xh)
  +hout_positive = U32.shrn(ph, 31n)
  +hout_negative = U32.shrn(mh, 31n)
  +ph_shifted = U32.or(U32.shl(ph), hin_positive)
  mh_shifted = U32.or(U32.shl(mh), hin_negative)
  next_pv = U32.or(mh_shifted, U32.not(U32.or(xv, ph_shifted)))
  next_mv = U32.and(ph_shifted, xv)
  (Block{next_pv, next_mv, U32.sub(U32.add(score, hout_positive), hout_negative)},
    Carry{hout_positive, hout_negative})

Uses (13):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Pair
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Sigma
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.add
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.and
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.not
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.or
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.shl
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.shrn
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.sub
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.xor
  https://jend.leeeet.dev/definition.txt?path=bend-edit-distance@0.2.2.0/src/Myers.bend&name=Block
  https://jend.leeeet.dev/definition.txt?path=bend-edit-distance@0.2.2.0/src/Myers.bend&name=Carry