translate.sqlx

config { hasOutput: true }
/*
 * Copyright 2019 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

CREATE OR REPLACE FUNCTION ${self()}(
  expression STRING,
  characters_to_replace STRING,
  characters_to_substitute STRING) 
AS (
  IF(
      LENGTH(characters_to_replace) < LENGTH(characters_to_substitute)
        OR LENGTH(expression) < LENGTH(characters_to_replace),
      expression,
      (
        SELECT
          STRING_AGG( 
           	  IFNULL( 
           	      (
                    SELECT
                      ARRAY_CONCAT([c], SPLIT(characters_to_substitute, ''))
                      [SAFE_OFFSET(
                          (
                            SELECT IFNULL(MIN(o2) + 1, 0)
                            FROM UNNEST(SPLIT(characters_to_replace, '')) AS k
                            WITH OFFSET o2
                            WHERE k = c
                          ))]
                  ),
                  ''), 
           	  '' ORDER BY o1)
        FROM UNNEST(SPLIT(expression, '')) AS c
        WITH OFFSET o1
      )) 
);