Cli.valid_nat: def of cli@0.2.0.0
Import: import cli@0.2.0.0/cli.bend as Cli
Lines 1930-1934 of cli@0.2.0.0/cli.bend: https://jend.leeeet.dev/read.txt?path=cli@0.2.0.0/cli.bend&start_line=1930&end_line=1934

import Base

# A Nat value is what Nat.read reads (P22): digits that, less leading
# zeroes, fit under its cap of 2^48-1.
def valid_nat(+s: String) -> Bool:
  Bool.and(Bool.not(String.is_empty(s)),
    Bool.and(decimal_digits(s), Nat.read.fits(Nat.read.trim(s))))

Uses (8):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  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=Nat.read.fits
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.read.trim
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String.is_empty
  https://jend.leeeet.dev/definition.txt?path=cli@0.2.0.0/cli.bend&name=decimal_digits