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| author | padre@elte.hu <padre@elte.hu> | 2004-03-19 14:56:09 +0000 |
|---|---|---|
| committer | Rafael Garcia-Suarez <rgarciasuarez@gmail.com> | 2004-03-22 20:46:52 +0000 |
| commit | 882672714c7b1c946ae8e88a96766a508485d95e (patch) | |
| tree | eba1b47908cb831874d33ad619b26adfad178b3a /pod/perlsub.pod | |
| parent | 2b1846f42207c006f0202b15d58a3d49680ec8e0 (diff) | |
| download | perl-882672714c7b1c946ae8e88a96766a508485d95e.tar.gz | |
Clarifications on constants subroutines, based on:
Subject: [perl #27768] [patch] wrong examples in perlsub/"Constant Functions"
From: "padre@elte.hu (via RT)" <perlbug-followup@perl.org>
Message-ID: <rt-3.0.8-27768-82310.5.12766475665209@perl.org>
p4raw-id: //depot/perl@22557
Diffstat (limited to 'pod/perlsub.pod')
| -rw-r--r-- | pod/perlsub.pod | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/pod/perlsub.pod b/pod/perlsub.pod index e830130a55..3619014e66 100644 --- a/pod/perlsub.pod +++ b/pod/perlsub.pod @@ -1133,7 +1133,17 @@ The following functions would all be inlined: sub FLAG_MASK () { FLAG_FOO | FLAG_BAR } sub OPT_BAZ () { not (0x1B58 & FLAG_MASK) } - sub BAZ_VAL () { + + sub N () { int(OPT_BAZ) / 3 } + + sub FOO_SET () { 1 if FLAG_MASK & FLAG_FOO } + +Be aware that these will not be inlined; as they contain inner scopes, +the constant folding doesn't reduce them to a single constant: + + sub foo_set () { if (FLAG_MASK & FLAG_FOO) { 1 } } + + sub baz_val () { if (OPT_BAZ) { return 23; } @@ -1142,13 +1152,6 @@ The following functions would all be inlined: } } - sub N () { int(BAZ_VAL) / 3 } - BEGIN { - my $prod = 1; - for (1..N) { $prod *= $_ } - sub N_FACTORIAL () { $prod } - } - If you redefine a subroutine that was eligible for inlining, you'll get a mandatory warning. (You can use this warning to tell whether or not a particular subroutine is considered constant.) The warning is |