Allow psql's \df and \do commands to specify argument types.

When dealing with overloaded function or operator names, having
to look through a long list of matches is tedious.  Let's extend
these commands to allow specification of (input) argument types
to let such results be trimmed down.  Each additional argument
is treated the same as the pattern argument of \dT and matched
against the appropriate argument's type name.

While at it, fix \dT (and these new options) to recognize the
usual notation of "foo[]" for "the array type over foo", and
to handle the special abbreviations allowed by the backend
grammar, such as "int" for "integer".

Greg Sabino Mullane, revised rather significantly by me

Discussion: https://postgr.es/m/CAKAnmmLF9Hhu02N+s7uAyLc5J1xZReg72HQUoiKhNiJV3_jACQ@mail.gmail.com

1 files changed, 168 insertions, 13 deletions

diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 52f7b2ce78c..fdc2a89085a 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -28,6 +28,7 @@
 #include "settings.h"
 #include "variables.h"
 
+static const char *map_typename_pattern(const char *pattern);
 static bool describeOneTableDetails(const char *schemaname,
 									const char *relationname,
 									const char *oid,
@@ -312,7 +313,9 @@ describeTablespaces(const char *pattern, bool verbose)
  * and you can mix and match these in any order.
  */
 bool
-describeFunctions(const char *functypes, const char *pattern, bool verbose, bool showSystem)
+describeFunctions(const char *functypes, const char *func_pattern,
+				  char **arg_patterns, int num_arg_patterns,
+				  bool verbose, bool showSystem)
 {
 	bool		showAggregate = strchr(functypes, 'a') != NULL;
 	bool		showNormal = strchr(functypes, 'n') != NULL;
@@ -524,6 +527,14 @@ describeFunctions(const char *functypes, const char *pattern, bool verbose, bool
 						 "\nFROM pg_catalog.pg_proc p"
 						 "\n     LEFT JOIN pg_catalog.pg_namespace n ON n.oid = p.pronamespace\n");
 
+	for (int i = 0; i < num_arg_patterns; i++)
+	{
+		appendPQExpBuffer(&buf,
+						  "     LEFT JOIN pg_catalog.pg_type t%d ON t%d.oid = p.proargtypes[%d]\n"
+						  "     LEFT JOIN pg_catalog.pg_namespace nt%d ON nt%d.oid = t%d.typnamespace\n",
+						  i, i, i, i, i, i);
+	}
+
 	if (verbose)
 		appendPQExpBufferStr(&buf,
 							 "     LEFT JOIN pg_catalog.pg_language l ON l.oid = p.prolang\n");
@@ -629,11 +640,43 @@ describeFunctions(const char *functypes, const char *pattern, bool verbose, bool
 		appendPQExpBufferStr(&buf, "      )\n");
 	}
 
-	processSQLNamePattern(pset.db, &buf, pattern, have_where, false,
+	processSQLNamePattern(pset.db, &buf, func_pattern, have_where, false,
 						  "n.nspname", "p.proname", NULL,
 						  "pg_catalog.pg_function_is_visible(p.oid)");
 
-	if (!showSystem && !pattern)
+	for (int i = 0; i < num_arg_patterns; i++)
+	{
+		if (strcmp(arg_patterns[i], "-") != 0)
+		{
+			/*
+			 * Match type-name patterns against either internal or external
+			 * name, like \dT.  Unlike \dT, there seems no reason to
+			 * discriminate against arrays or composite types.
+			 */
+			char		nspname[64];
+			char		typname[64];
+			char		ft[64];
+			char		tiv[64];
+
+			snprintf(nspname, sizeof(nspname), "nt%d.nspname", i);
+			snprintf(typname, sizeof(typname), "t%d.typname", i);
+			snprintf(ft, sizeof(ft),
+					 "pg_catalog.format_type(t%d.oid, NULL)", i);
+			snprintf(tiv, sizeof(tiv),
+					 "pg_catalog.pg_type_is_visible(t%d.oid)", i);
+			processSQLNamePattern(pset.db, &buf,
+								  map_typename_pattern(arg_patterns[i]),
+								  true, false,
+								  nspname, typname, ft, tiv);
+		}
+		else
+		{
+			/* "-" pattern specifies no such parameter */
+			appendPQExpBuffer(&buf, "  AND t%d.typname IS NULL\n", i);
+		}
+	}
+
+	if (!showSystem && !func_pattern)
 		appendPQExpBufferStr(&buf, "      AND n.nspname <> 'pg_catalog'\n"
 							 "      AND n.nspname <> 'information_schema'\n");
 
@@ -746,20 +789,24 @@ describeTypes(const char *pattern, bool verbose, bool showSystem)
 						 "WHERE c.oid = t.typrelid))\n");
 
 	/*
-	 * do not include array types (before 8.3 we have to use the assumption
-	 * that their names start with underscore)
+	 * do not include array types unless the pattern contains [] (before 8.3
+	 * we have to use the assumption that their names start with underscore)
 	 */
-	if (pset.sversion >= 80300)
-		appendPQExpBufferStr(&buf, "  AND NOT EXISTS(SELECT 1 FROM pg_catalog.pg_type el WHERE el.oid = t.typelem AND el.typarray = t.oid)\n");
-	else
-		appendPQExpBufferStr(&buf, "  AND t.typname !~ '^_'\n");
+	if (pattern == NULL || strstr(pattern, "[]") == NULL)
+	{
+		if (pset.sversion >= 80300)
+			appendPQExpBufferStr(&buf, "  AND NOT EXISTS(SELECT 1 FROM pg_catalog.pg_type el WHERE el.oid = t.typelem AND el.typarray = t.oid)\n");
+		else
+			appendPQExpBufferStr(&buf, "  AND t.typname !~ '^_'\n");
+	}
 
 	if (!showSystem && !pattern)
 		appendPQExpBufferStr(&buf, "      AND n.nspname <> 'pg_catalog'\n"
 							 "      AND n.nspname <> 'information_schema'\n");
 
 	/* Match name pattern against either internal or external name */
-	processSQLNamePattern(pset.db, &buf, pattern, true, false,
+	processSQLNamePattern(pset.db, &buf, map_typename_pattern(pattern),
+						  true, false,
 						  "n.nspname", "t.typname",
 						  "pg_catalog.format_type(t.oid, NULL)",
 						  "pg_catalog.pg_type_is_visible(t.oid)");
@@ -781,13 +828,69 @@ describeTypes(const char *pattern, bool verbose, bool showSystem)
 	return true;
 }
 
+/*
+ * Map some variant type names accepted by the backend grammar into
+ * canonical type names.
+ *
+ * Helper for \dT and other functions that take typename patterns.
+ * This doesn't completely mask the fact that these names are special;
+ * for example, a pattern of "dec*" won't magically match "numeric".
+ * But it goes a long way to reduce the surprise factor.
+ */
+static const char *
+map_typename_pattern(const char *pattern)
+{
+	static const char *const typename_map[] = {
+		/*
+		 * These names are accepted by gram.y, although they are neither the
+		 * "real" name seen in pg_type nor the canonical name printed by
+		 * format_type().
+		 */
+		"decimal", "numeric",
+		"float", "double precision",
+		"int", "integer",
+
+		/*
+		 * We also have to map the array names for cases where the canonical
+		 * name is different from what pg_type says.
+		 */
+		"bool[]", "boolean[]",
+		"decimal[]", "numeric[]",
+		"float[]", "double precision[]",
+		"float4[]", "real[]",
+		"float8[]", "double precision[]",
+		"int[]", "integer[]",
+		"int2[]", "smallint[]",
+		"int4[]", "integer[]",
+		"int8[]", "bigint[]",
+		"time[]", "time without time zone[]",
+		"timetz[]", "time with time zone[]",
+		"timestamp[]", "timestamp without time zone[]",
+		"timestamptz[]", "timestamp with time zone[]",
+		"varbit[]", "bit varying[]",
+		"varchar[]", "character varying[]",
+		NULL
+	};
+
+	if (pattern == NULL)
+		return NULL;
+	for (int i = 0; typename_map[i] != NULL; i += 2)
+	{
+		if (pg_strcasecmp(pattern, typename_map[i]) == 0)
+			return typename_map[i + 1];
+	}
+	return pattern;
+}
+
 
 /*
  * \do
  * Describe operators
  */
 bool
-describeOperators(const char *pattern, bool verbose, bool showSystem)
+describeOperators(const char *oper_pattern,
+				  char **arg_patterns, int num_arg_patterns,
+				  bool verbose, bool showSystem)
 {
 	PQExpBufferData buf;
 	PGresult   *res;
@@ -836,14 +939,66 @@ describeOperators(const char *pattern, bool verbose, bool showSystem)
 					  "     LEFT JOIN pg_catalog.pg_namespace n ON n.oid = o.oprnamespace\n",
 					  gettext_noop("Description"));
 
-	if (!showSystem && !pattern)
+	if (num_arg_patterns >= 2)
+	{
+		num_arg_patterns = 2;	/* ignore any additional arguments */
+		appendPQExpBufferStr(&buf,
+							 "     LEFT JOIN pg_catalog.pg_type t0 ON t0.oid = o.oprleft\n"
+							 "     LEFT JOIN pg_catalog.pg_namespace nt0 ON nt0.oid = t0.typnamespace\n"
+							 "     LEFT JOIN pg_catalog.pg_type t1 ON t1.oid = o.oprright\n"
+							 "     LEFT JOIN pg_catalog.pg_namespace nt1 ON nt1.oid = t1.typnamespace\n");
+	}
+	else if (num_arg_patterns == 1)
+	{
+		appendPQExpBufferStr(&buf,
+							 "     LEFT JOIN pg_catalog.pg_type t0 ON t0.oid = o.oprright\n"
+							 "     LEFT JOIN pg_catalog.pg_namespace nt0 ON nt0.oid = t0.typnamespace\n");
+	}
+
+	if (!showSystem && !oper_pattern)
 		appendPQExpBufferStr(&buf, "WHERE n.nspname <> 'pg_catalog'\n"
 							 "      AND n.nspname <> 'information_schema'\n");
 
-	processSQLNamePattern(pset.db, &buf, pattern, !showSystem && !pattern, true,
+	processSQLNamePattern(pset.db, &buf, oper_pattern,
+						  !showSystem && !oper_pattern, true,
 						  "n.nspname", "o.oprname", NULL,
 						  "pg_catalog.pg_operator_is_visible(o.oid)");
 
+	if (num_arg_patterns == 1)
+		appendPQExpBufferStr(&buf, "  AND o.oprleft = 0\n");
+
+	for (int i = 0; i < num_arg_patterns; i++)
+	{
+		if (strcmp(arg_patterns[i], "-") != 0)
+		{
+			/*
+			 * Match type-name patterns against either internal or external
+			 * name, like \dT.  Unlike \dT, there seems no reason to
+			 * discriminate against arrays or composite types.
+			 */
+			char		nspname[64];
+			char		typname[64];
+			char		ft[64];
+			char		tiv[64];
+
+			snprintf(nspname, sizeof(nspname), "nt%d.nspname", i);
+			snprintf(typname, sizeof(typname), "t%d.typname", i);
+			snprintf(ft, sizeof(ft),
+					 "pg_catalog.format_type(t%d.oid, NULL)", i);
+			snprintf(tiv, sizeof(tiv),
+					 "pg_catalog.pg_type_is_visible(t%d.oid)", i);
+			processSQLNamePattern(pset.db, &buf,
+								  map_typename_pattern(arg_patterns[i]),
+								  true, false,
+								  nspname, typname, ft, tiv);
+		}
+		else
+		{
+			/* "-" pattern specifies no such parameter */
+			appendPQExpBuffer(&buf, "  AND t%d.typname IS NULL\n", i);
+		}
+	}
+
 	appendPQExpBufferStr(&buf, "ORDER BY 1, 2, 3, 4;");
 
 	res = PSQLexec(buf.data);