Split the plpython regression test into test cases arranged by topic, instead

of the previous monolithic setup-create-run sequence, that was apparently
inherited from a previous test infrastructure, but makes working with the
tests and adding new ones weird.

src/pl/plpython/sql/plpython_spi.sql

@@ -0,0 +1,90 @@
+
+
+-- nested calls
+--
+
+CREATE FUNCTION nested_call_one(a text) RETURNS text
+	AS
+'q = "SELECT nested_call_two(''%s'')" % a
+r = plpy.execute(q)
+return r[0]'
+	LANGUAGE plpythonu ;
+
+CREATE FUNCTION nested_call_two(a text) RETURNS text
+	AS
+'q = "SELECT nested_call_three(''%s'')" % a
+r = plpy.execute(q)
+return r[0]'
+	LANGUAGE plpythonu ;
+
+CREATE FUNCTION nested_call_three(a text) RETURNS text
+	AS
+'return a'
+	LANGUAGE plpythonu ;
+
+-- some spi stuff
+
+CREATE FUNCTION spi_prepared_plan_test_one(a text) RETURNS text
+	AS
+'if not SD.has_key("myplan"):
+	q = "SELECT count(*) FROM users WHERE lname = $1"
+	SD["myplan"] = plpy.prepare(q, [ "text" ])
+try:
+	rv = plpy.execute(SD["myplan"], [a])
+	return "there are " + str(rv[0]["count"]) + " " + str(a) + "s"
+except Exception, ex:
+	plpy.error(str(ex))
+return None
+'
+	LANGUAGE plpythonu;
+
+CREATE FUNCTION spi_prepared_plan_test_nested(a text) RETURNS text
+	AS
+'if not SD.has_key("myplan"):
+	q = "SELECT spi_prepared_plan_test_one(''%s'') as count" % a
+	SD["myplan"] = plpy.prepare(q)
+try:
+	rv = plpy.execute(SD["myplan"])
+	if len(rv):
+		return rv[0]["count"]
+except Exception, ex:
+	plpy.error(str(ex))
+return None
+'
+	LANGUAGE plpythonu;
+
+
+
+
+CREATE FUNCTION join_sequences(s sequences) RETURNS text
+	AS
+'if not s["multipart"]:
+	return s["sequence"]
+q = "SELECT sequence FROM xsequences WHERE pid = ''%s''" % s["pid"]
+rv = plpy.execute(q)
+seq = s["sequence"]
+for r in rv:
+	seq = seq + r["sequence"]
+return seq
+'
+	LANGUAGE plpythonu;
+
+
+
+
+
+-- spi and nested calls
+--
+select nested_call_one('pass this along');
+select spi_prepared_plan_test_one('doe');
+select spi_prepared_plan_test_one('smith');
+select spi_prepared_plan_test_nested('smith');
+
+
+
+
+SELECT join_sequences(sequences) FROM sequences;
+SELECT join_sequences(sequences) FROM sequences
+	WHERE join_sequences(sequences) ~* '^A';
+SELECT join_sequences(sequences) FROM sequences
+	WHERE join_sequences(sequences) ~* '^B';