/usr/share/perl5/Math/Calc/Units/Grammar.y is in libmath-calc-units-perl 1.07-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 | # To process: yapp -s -m Math::Calc::Units::Grammar Grammar.y
%{
use Math::Calc::Units::Compute qw(plus minus mult divide power construct);
%}
# Lowest
%nonassoc BARE_UNIT
%nonassoc NUMBER CONSTRUCT
%left '+' '-'
%left '*' '/'
%left WORD
%left '**'
# Highest
%%
START : expr
| '#' unit
;
expr : expr '+' expr { return plus($_[1], $_[3]); }
| expr '-' expr { return minus($_[1], $_[3]); }
| expr '*' expr { return mult($_[1], $_[3]); }
| expr '/' expr { return divide($_[1], $_[3]); }
| expr '**' expr { return power($_[1], $_[3]); }
| '(' expr ')' { return $_[2]; }
| value { return $_[1]; }
| expr unit { return mult($_[1], [ 1, $_[2] ]); }
;
value : NUMBER unit
{ return [ $_[1] => $_[2] ] }
| unit %prec BARE_UNIT
{ return [ 1 => $_[1] ] }
| NUMBER { return [ $_[1] => {} ] }
| '-' NUMBER { return [ -$_[2] => {} ] }
| '@' NUMBER { return [ $_[2] => { 'timestamp' => 1 } ] }
| CONSTRUCT { return construct($_[1]) }
;
unit : WORD { return { $_[1] => 1 } }
| WORD WORD { my $u = {}; $u->{$_[1]}++; $u->{$_[2]}++; return $u; }
;
%%
|