Scan.number.class: def of gralha-text-scan@0.1.0.1
Import: import gralha-text-scan@0.1.0.1/scan.bend as Scan
Lines 138-150 of gralha-text-scan@0.1.0.1/scan.bend: https://jend.leeeet.dev/read.txt?path=gralha-text-scan@0.1.0.1/scan.bend&start_line=138&end_line=150

import Base

# A number is read straight into a float: digits accumulate the mantissa
# (fraction digits also scale a divisor), an exponent accumulates its own
# digits, and a sign is taken where it may appear. Nothing is copied into a
# scratch string. Each character is classified one step ahead, so the loop
# branches on parameters: class 0 digit, 1 dot, 2 exponent mark, 3 sign,
# 4 anything else; stage 0 start, 1 mantissa, 2 fraction, 3 after the
# mark, 4 exponent digits. An exponent mark that no digit follows is not
# part of the number (as in "1em"), so `mark` keeps what was read from the
# mark on (the mark and any signs, reversed) to give back in that case.
def number.class(+c: U32) -> U32:
  choose(U32, digit(c), 0, choose(U32, U32.is_eq(c, 46), 1,
    choose(U32, U32.is_eq(c, 101) || U32.is_eq(c, 69), 2,
      choose(U32, U32.is_eq(c, 43) || U32.is_eq(c, 45), 3, 4))))

Uses (5):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.or
  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_eq
  https://jend.leeeet.dev/definition.txt?path=gralha-text-scan@0.1.0.1/scan.bend&name=choose
  https://jend.leeeet.dev/definition.txt?path=gralha-text-scan@0.1.0.1/scan.bend&name=digit