#!./perl BEGIN { chdir 't'; @INC = '../lib'; require './test.pl'; } use strict; use warnings; plan (8); # Historically constant folding was performed by evaluating the ops, and if # they threw an exception compilation failed. This was seen as buggy, because # even illegal constants in unreachable code would cause failure. So now # illegal expressions are reported at runtime, if the expression is reached, # making constant folding consistent with many other languages, and purely an # optimisation rather than a behaviour change. my $a; $a = eval '$b = 0/0 if 0; 3'; is ($a, 3); is ($@, ""); my $b = 0; $a = eval 'if ($b) {return sqrt -3} 3'; is ($a, 3); is ($@, ""); $a = eval q{ $b = eval q{if ($b) {return log 0} 4}; is ($b, 4); is ($@, ""); 5; }; is ($a, 5); is ($@, "");