Re: useless use of void context work-around

Message-ID: <m3g0jofo8f.fsf@ak-71.mind.de>

Document (comment) the q(di ds ig) trick in the code.

p4raw-id: //depot/perl@8194

diff --git a/op.c b/op.c
index e6f7804..e40d334 100644 (file)
--- a/op.c
+++ b/op.c
@@ -1118,6 +1118,12 @@ Perl_scalarvoid(pTHX_ OP *o)
                if (SvNIOK(sv) && (SvNV(sv) == 0.0 || SvNV(sv) == 1.0))
                    useless = 0;
                else if (SvPOK(sv)) {
+                  /* perl4's way of mixing documentation and code
+                     (before the invention of POD) was based on a
+                     trick to mix nroff and perl code. The trick was
+                     built upon these three nroff macros being used in
+                     void context. The pink camel has the details in
+                     the script wrapman near page 319. */
                    if (strnEQ(SvPVX(sv), "di", 2) ||
                        strnEQ(SvPVX(sv), "ds", 2) ||
                        strnEQ(SvPVX(sv), "ig", 2))