Cover.runs.over: def of gralha-coverage@0.1.0.1
Import: import gralha-coverage@0.1.0.1/cover.bend as Cover
Lines 111-124 of gralha-coverage@0.1.0.1/cover.bend: https://jend.leeeet.dev/read.txt?path=gralha-coverage@0.1.0.1/cover.bend&start_line=111&end_line=124

import Base
import gralha-text-scan@0.1.0.1/scan.bend as U

# The mask's coverage over the grid rectangle [x0, x1) by [y0, y1) when it is
# uniform (2 means "unvisited", so an empty rectangle reads as uniform 0), else -1.
# The uniform value of runs over the columns [x0, x1): a run covering them
# all gives its value, none touching them gives 0, anything else -1.
def runs.over(rs: List<&2, Run>, +x0: U32, +x1: U32, +acc: F32) -> F32:
  match rs:
    case Nil{}: U.choose(F32, F32.is_gt(acc, 1.5), 0.0, acc)
    case Con{Run{a, b, v}, rest}:
      +aa = a
      +bb = b
      +vv = v
      +overlaps = U32.is_lt(aa, x1) && U32.is_lt(x0, bb)
      +covers = U32.is_le(aa, x0) && U32.is_ge(bb, x1)
      runs.over(rest, x0, x1, U.choose(F32, Bool.not(overlaps), acc, U.choose(F32, covers && F32.is_gt(acc, 1.5), vv, F32.neg(1.0))))

Uses (12):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.and
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.not
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=F32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=F32.is_gt
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=F32.neg
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.is_ge
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.is_le
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.is_lt
  https://jend.leeeet.dev/definition.txt?path=gralha-coverage@0.1.0.1/cover.bend&name=Run
  https://jend.leeeet.dev/definition.txt?path=gralha-text-scan@0.1.0.1/scan.bend&name=choose