F64.sig63: def of bend-collections-laws-math@1.0.0.0
Import: import bend-collections-laws-math@1.0.0.0/src/math/f64.bend as F64
Lines 607-614 of bend-collections-laws-math@1.0.0.0/src/math/f64.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-math@1.0.0.0/src/math/f64.bend&start_line=607&end_line=614

import Base
import bend-collections-laws-math@1.0.0.0/src/math/u64.bend as W
import bend-collections-laws-math@1.0.0.0/src/math/w64.bend as X

# n with its top bit moved to bit 62 (b = bit_length(n)): shifted up when
# b <= 63 (every runtime Nat), jammed down otherwise
def sig63(+n: Nat, +b: Nat, fits: Bool) -> W.U64:
  match fits:
    case True{}:
      X.shl(word64(n), Nat.sub(63n, b))
    case False{}:
      word64(jam_nat(Nat.sub(b, 63n), n))

Uses (7):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.sub
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/src/math/f64.bend&name=jam_nat
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/src/math/f64.bend&name=word64
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/src/math/u64.bend&name=U64
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-math@1.0.0.0/src/math/w64.bend&name=shl