def W64.read

bendtorch-load@1.3.0.0 · main.bend:102

import Base

102# A decimal number of 1 to 19 digits (every such number fits 64 bits); anything else is None
103def W64.read(s: String) -> Maybe<&2, W64>:
104  match s:
105    case SNil{}: None{}
106    case SCon{+h, +t}: W64.read_if(W64.digits(SCon{h, t}, 19n), SCon{h, t})