Add to_regtypemod() Function

doc/src/sgml/func.sgml

@@ -24872,7 +24872,7 @@ SELECT pg_type_is_visible('myschema.widget'::regtype);
 
      <tbody>
       <row>
-       <entry role="func_table_entry"><para role="func_signature">
+       <entry id="format_type" xreflabel="format_type" role="func_table_entry"><para role="func_signature">
         <indexterm>
          <primary>format_type</primary>
         </indexterm>
@@ -25570,21 +25570,61 @@ SELECT collation for ('foo' COLLATE "de_DE");
       </row>
 
       <row>
-       <entry role="func_table_entry"><para role="func_signature">
+       <entry id="to_regtype" xreflabel="to_regtype" role="func_table_entry"><para role="func_signature">
         <indexterm>
          <primary>to_regtype</primary>
         </indexterm>
         <function>to_regtype</function> ( <type>text</type> )
         <returnvalue>regtype</returnvalue>
        </para>
        <para>
-        Translates a textual type name to its OID.  A similar result is
-        obtained by casting the string to type <type>regtype</type> (see
-        <xref linkend="datatype-oid"/>); however, this function will return
-        <literal>NULL</literal> rather than throwing an error if the name is
-        not found.
+        Parses a string of text, extracts a potential type name from it, and
+        translates that name into an OID. A similar result is obtained by
+        casting the string to type <type>regtype</type> (see
+        <xref linkend="datatype-oid"/>). Failure to extract a valid potential
+        type name results in an error. For example:
+<programlisting>
+SELECT to_regtype('interval nonesuch');
+ERROR:  syntax error at or near "nonesuch"
+LINE 1: select to_regtype('interval nonesuch');
+                 ^
+CONTEXT:  invalid type name "interval nonesuch"
+</programlisting>
+        However, if the extracted name is not known to the system, this function
+        will return <literal>NULL</literal>. For example:
+<programlisting>
+SELECT to_regtype('party');
+ to_regtype
+------------
+
+</programlisting>
+       </para></entry>
+      </row>
+
+      <row>
+       <entry id="to_regtypemod" role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>to_regtypemod</primary>
+        </indexterm>
+        <function>to_regtypemod</function> ( <type>text</type> )
+        <returnvalue>integer</returnvalue>
+       </para>
+       <para>
+        Parses a string of text, extracts a potential type name from it, and
+        translates its type modifier, if any. Failure to extract a valid
+        potential type name results in an error; however, if the extracted name
+        is not known to the system, this function will return
+        <literal>NULL</literal>. Complements <xref linkend="to_regtype"/>, and
+        can be passed to <xref linkend="format_type" />. For example:
+<programlisting>
+SELECT format_type(to_regtype('varchar(32)'), to_regtypemod('varchar(32)'));
+      format_type
+-----------------------
+ character varying(32)
+</programlisting>
        </para></entry>
       </row>
+
      </tbody>
     </tgroup>
    </table>

src/backend/catalog/genbki.pl

@@ -1098,7 +1098,7 @@ sub lookup_oids
 			{
 				warn sprintf
 				  "unresolved OID reference \"%s\" in %s.dat field %s line %s\n",
-				  $lookupname, $catname, $attname, $bki_values->{line_number};
+				  $lookupname || '', $catname || '', $attname || '', $bki_values->{line_number} || '';
 				$num_errors++;
 			}
 		}

src/backend/utils/adt/regproc.c

@@ -1220,6 +1220,35 @@ to_regtype(PG_FUNCTION_ARGS)
 	PG_RETURN_DATUM(result);
 }
 
+
+/*
+ * to_regtypemod() complements to_regtype, returning the typmod for the type,
+ * if any.
+ *
+ * If the type name is not found, we return NULL.
+ *
+ * Internally it relies on the Postgres core parseTypeString() function defined
+ * in src/backend/parser/parse_type.c.
+ */
+Datum
+to_regtypemod(PG_FUNCTION_ARGS)
+{
+	char	   *typ_name = text_to_cstring(PG_GETARG_TEXT_PP(0));
+	Oid         typid;
+	int32       typmod;
+	ErrorSaveContext escontext = {T_ErrorSaveContext};
+
+	/*
+	 * Parse type-name argument to obtain the encoded typmod. Return NULL
+	 * on failure.
+	 */
+	if (!parseTypeString(typ_name, &typid, &typmod, (Node *) &escontext)) {
+		PG_RETURN_NULL();
+	}
+
+	PG_RETURN_INT32(typmod);
+}
+
 /*
  * regtypeout		- converts type OID to "typ_name"
  */

src/include/catalog/pg_proc.dat

@@ -7155,6 +7155,9 @@
 { oid => '3493', descr => 'convert type name to regtype',
   proname => 'to_regtype', provolatile => 's', prorettype => 'regtype',
   proargtypes => 'text', prosrc => 'to_regtype' },
+{ oid => '8401', descr => 'convert type name to type mod',
+  proname => 'to_regtypemod', provolatile => 's', prorettype => 'int4',
+  proargtypes => 'text', prosrc => 'to_regtypemod' },
 { oid => '1079', descr => 'convert text to regclass',
   proname => 'regclass', provolatile => 's', prorettype => 'regclass',
   proargtypes => 'text', prosrc => 'text_regclass' },

src/test/regress/expected/regproc.out

@@ -544,3 +544,69 @@ SELECT * FROM pg_input_error_info('way.too.many.names', 'regtype');
 ERROR:  improper qualified name (too many dotted names): way.too.many.names
 SELECT * FROM pg_input_error_info('no_such_catalog.schema.name', 'regtype');
 ERROR:  cross-database references are not implemented: no_such_catalog.schema.name
+-- Test to_regtypemod
+SELECT to_regtypemod('text');
+ to_regtypemod 
+---------------
+            -1
+(1 row)
+
+SELECT to_regtypemod('timestamp(4)');
+ to_regtypemod 
+---------------
+             4
+(1 row)
+
+SELECT to_regtypemod('interval(0)');
+ to_regtypemod 
+---------------
+    2147418112
+(1 row)
+
+SELECT to_regtypemod('interval second(0)');
+ to_regtypemod 
+---------------
+     268435456
+(1 row)
+
+SELECT to_regtypemod('timestamptz');
+ to_regtypemod 
+---------------
+            -1
+(1 row)
+
+SELECT to_regtypemod('timestamptz(6)');
+ to_regtypemod 
+---------------
+             6
+(1 row)
+
+SELECT to_regtypemod('varchar');
+ to_regtypemod 
+---------------
+            -1
+(1 row)
+
+SELECT to_regtypemod('varchar(128)');
+ to_regtypemod 
+---------------
+           132
+(1 row)
+
+SELECT to_regtypemod(NULL);                -- returns null on null input
+ to_regtypemod 
+---------------
+
+(1 row)
+
+SELECT to_regtypemod('year(4)');           -- error trapped, returns null
+ to_regtypemod 
+---------------
+
+(1 row)
+
+SELECT to_regtypemod('interval nonesuch'); -- grammar error raised, not trapped
+ERROR:  syntax error at or near "nonesuch"
+LINE 1: SELECT to_regtypemod('interval nonesuch');
+                 ^
+CONTEXT:  invalid type name "interval nonesuch"

src/test/regress/sql/regproc.sql

@@ -145,3 +145,17 @@ SELECT * FROM pg_input_error_info('incorrect type name syntax', 'regtype');
 SELECT * FROM pg_input_error_info('numeric(1,2,3)', 'regtype');  -- bogus typmod
 SELECT * FROM pg_input_error_info('way.too.many.names', 'regtype');
 SELECT * FROM pg_input_error_info('no_such_catalog.schema.name', 'regtype');
+
+-- Test to_regtypemod
+SELECT to_regtypemod('text');
+SELECT to_regtypemod('timestamp(4)');
+SELECT to_regtypemod('interval(0)');
+SELECT to_regtypemod('interval second(0)');
+SELECT to_regtypemod('timestamptz');
+SELECT to_regtypemod('timestamptz(6)');
+SELECT to_regtypemod('varchar');
+SELECT to_regtypemod('varchar(128)');
+
+SELECT to_regtypemod(NULL);                -- returns null on null input
+SELECT to_regtypemod('year(4)');           -- error trapped, returns null
+SELECT to_regtypemod('interval nonesuch'); -- grammar error raised, not trapped