BendtorchLoad.W64.read: def of bendtorch-load@1.3.0.0
Import: import bendtorch-load@1.3.0.0/main.bend as BendtorchLoad
Lines 102-106 of bendtorch-load@1.3.0.0/main.bend: https://jend.leeeet.dev/read.txt?path=bendtorch-load@1.3.0.0/main.bend&start_line=102&end_line=106

import Base

# A decimal number of 1 to 19 digits (every such number fits 64 bits); anything else is None
def W64.read(s: String) -> Maybe<&2, W64>:
  match s:
    case SNil{}: None{}
    case SCon{+h, +t}: W64.read_if(W64.digits(SCon{h, t}, 19n), SCon{h, t})

Uses (5):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String
  https://jend.leeeet.dev/definition.txt?path=bendtorch-load@1.3.0.0/main.bend&name=W64
  https://jend.leeeet.dev/definition.txt?path=bendtorch-load@1.3.0.0/main.bend&name=W64.digits
  https://jend.leeeet.dev/definition.txt?path=bendtorch-load@1.3.0.0/main.bend&name=W64.read_if