Add psql tab completion for DO blocks.

Also adjust documentation of DO.

Patch from David Fetter and subsequent discussion.

doc/src/sgml/ref/do.sgml

 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/do.sgml,v 1.3 2010/01/26 16:33:40 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/do.sgml,v 1.4 2010/02/15 02:55:01 itagaki Exp $
 PostgreSQL documentation
 -->
 
@@ -25,7 +25,7 @@ PostgreSQL documentation
 
  <refsynopsisdiv>
 <synopsis>
-DO <replaceable class="PARAMETER">code</replaceable> [ LANGUAGE <replaceable class="PARAMETER">lang_name</replaceable> ]
+DO { [ LANGUAGE <replaceable class="PARAMETER">lang_name</replaceable> ] | <replaceable class="PARAMETER">code</replaceable> } ...
 </synopsis>
  </refsynopsisdiv>
 

src/bin/psql/tab-complete.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2010, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/psql/tab-complete.c,v 1.192 2010/01/25 18:23:09 heikki Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/tab-complete.c,v 1.193 2010/02/15 02:55:01 itagaki Exp $
  */
 
 /*----------------------------------------------------------------------
@@ -618,7 +618,7 @@ psql_completion(char *text, int start, int end)
 	static const char *const sql_commands[] = {
 		"ABORT", "ALTER", "ANALYZE", "BEGIN", "CHECKPOINT", "CLOSE", "CLUSTER",
 		"COMMENT", "COMMIT", "COPY", "CREATE", "DEALLOCATE", "DECLARE",
-		"DELETE FROM", "DISCARD", "DROP", "END", "EXECUTE", "EXPLAIN", "FETCH",
+		"DELETE FROM", "DISCARD", "DO", "DROP", "END", "EXECUTE", "EXPLAIN", "FETCH",
 		"GRANT", "INSERT", "LISTEN", "LOAD", "LOCK", "MOVE", "NOTIFY", "PREPARE",
 		"REASSIGN", "REINDEX", "RELEASE", "RESET", "REVOKE", "ROLLBACK",
 		"SAVEPOINT", "SELECT", "SET", "SHOW", "START", "TABLE", "TRUNCATE", "UNLISTEN",
@@ -1532,6 +1532,18 @@ psql_completion(char *text, int start, int end)
 		COMPLETE_WITH_LIST(list_DISCARD);
 	}
 
+/* DO */
+	/*
+	 * Complete DO with LANGUAGE.
+	 */
+	else if (pg_strcasecmp(prev_wd, "DO") == 0)
+	{
+		static const char *const list_DO[] =
+		{"LANGUAGE", NULL};
+
+		COMPLETE_WITH_LIST(list_DO);
+	}
+
 /* DROP (when not the previous word) */
 	/* DROP AGGREGATE */
 	else if (pg_strcasecmp(prev3_wd, "DROP") == 0 &&