User-defined lexical pragma

• New in Perl 5.10

• %^H hints hash (compiletime)

• • $^H{yourpragma} = 1 in sub import
  • $^H{yourpragma} = 0 in sub unimport
  • Only "simple" scalars (integer, string)

• (caller 1)[10] ref -> %^H (runtime)

• • Inspect $h->{yourpragma} for status