Create contrib/bool_plperl to provide a bool transform for PL/Perl[U].

plperl's default handling of bool arguments or results is not terribly
satisfactory, since Perl doesn't consider the string 'f' to be false.
Ideally we'd just fix that, but the backwards-compatibility hazard
would be substantial.  Instead, build a TRANSFORM module that can
be optionally applied to provide saner semantics.

Perhaps usefully, this is also about the minimum possible skeletal
example of a plperl transform module; so it might be a better starting
point for user-written transform modules than hstore_plperl or
jsonb_plperl.

Ivan Panchenko

Discussion: https://postgr.es/m/1583013317.881182688@f390.i.mail.ru

1 files changed, 30 insertions, 0 deletions

diff --git a/contrib/bool_plperl/bool_plperl.c b/contrib/bool_plperl/bool_plperl.c
new file mode 100644
index 00000000000..0fa1eee8e57
--- /dev/null
+++ b/contrib/bool_plperl/bool_plperl.c
@@ -0,0 +1,30 @@
+#include "postgres.h"
+
+#include "fmgr.h"
+#include "plperl.h"
+
+
+PG_MODULE_MAGIC;
+
+PG_FUNCTION_INFO_V1(bool_to_plperl);
+
+Datum
+bool_to_plperl(PG_FUNCTION_ARGS)
+{
+	dTHX;
+	bool		in = PG_GETARG_BOOL(0);
+
+	return PointerGetDatum(in ? &PL_sv_yes : &PL_sv_no);
+}
+
+
+PG_FUNCTION_INFO_V1(plperl_to_bool);
+
+Datum
+plperl_to_bool(PG_FUNCTION_ARGS)
+{
+	dTHX;
+	SV		   *in = (SV *) PG_GETARG_POINTER(0);
+
+	PG_RETURN_BOOL(SvTRUE(in));
+}