FatRatStr

Description

FatRat Allomorph to parse NumStr or Str string to FatRat avoiding Num clipping. Provides the .FatRatStr coercion method.

The str attr contains the original literal. The Num literal is parsed and loaded into the fatrat attr.

Synopsis

say ~(<9.109_383e309>.FatRatStr * 2).FatRatStr eq '1.8218766e+310';  #True

e309 (and e-325) are the limits of double precision

Description

<1.6605402e-27>.FatRatStr;
#-or-
'1.6605402e-27'.FatRatStr;

#FatRatStr.new(
#    fatrat =>FatRat.new(8302701, 5000000000000000000000000000000000), 
#    str => "1.6605402e-27"
#)

Also, to streamline the pattern '1e-6'.FatRatStr.FatRat; (to get an actual FatRat), overrides the standard .FatRat method of NumStr and Str.

<1.6605402e-27>.FatRat;
#-or-
'1.6605402e-27'.FatRat;

#.FatRat @0
#├ $.numerator = 8302701   
#└ $.denominator = 5000000000000000000000000000000000

Notes

If you do FatRatStr math, you need to re-coerce the result from FatRat.

my $y = <9.109_383_701_5e309>.FatRatStr;
say ~($y *= 2).FatRatStr;

#1.8218767403e+310

The method .round(FatRatStr:D: Real $scale --> FatRatStr) {} is provided as a utility to do (unlimited precision) rounding.

The class method FatRatStr.make-str(FatRat:D $f --> Str) {} is provided as a utility to make the (unlimited precision) string representation.

Copyright 2025 Henley Cloud Consulting Ltd. Copyright 2026 Stephen Roe