>>884 Perl5、見易くするためインデントは全角スペースに置換してあります。

use feature qw{signatures}; no warnings 'experimental';
use Parse::RecDescent;
sub ope($valp, @args) { my $val = $valp->();
　while (@args) { my ($op, $parm) = splice @args, 0, 2; $op->($val, $parm->()); } $val }
%d = map{$_ => $i++} 0..9,'A'..'Z','a'..'z';
%e = map{$d{$_} => $_} keys %d;
use List::Util 'reduce';
sub dec($d62) { reduce {$a*62 + $b} map{$d{$_}} split '', $d62 }
my $parse = new Parse::RecDescent <<'End';
　expr: <leftop:term addsub term> {sub { ::ope @{$item[1]} }}
　addsub: '+' {sub { $_[0] += $_[1] }} | '-' {sub { $_[0] -= $_[1] }}
　term: <leftop:factor muldiv factor> { sub {::ope @{$item[1]} }}
　muldiv: '*' {sub { $_[0] *= $_[1] }} | '/' {sub { $_[0] /= $_[1] }}
　factor: dig62 | '(' expr ')' { $item[2] }
　dig62: /[0-9A-Za-z]+/ {sub { ::dec $item[1] }}
End
sub enc($d) { my $r = $d % 62; $d = int(($d - $r) / 62); $d ? (enc($d) . $e{$r}) : $e{$r}; }
for (<DATA>) {
　$n = $parse->expr($_)->();
　$n = $n < 0 ? '-' . enc(-$n) : enc($n);
　print "$_ = $n\n";
}
__DATA__
123 + ABC
4 - K
2023-7-4
printf - (Hello + world)
Windows * 11
The - quick - brown * fox + jumped - over + the - lazy * dog
ABCDEFG + HIJKLMNOP + QRSTUV + WXYZ