xref: /aosp_15_r20/external/ktfmt/core/src/main/java/com/facebook/ktfmt/format/WhitespaceTombstones.kt (revision 5be3f65c8cf0e6db0a7e312df5006e8e93cdf9ec)
1 /*
2  * Copyright (c) Meta Platforms, Inc. and affiliates.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.facebook.ktfmt.format
18 
19 import java.util.regex.Pattern
20 import java.util.regex.Pattern.MULTILINE
21 
22 object WhitespaceTombstones {
23   /** See [replaceTrailingWhitespaceWithTombstone]. */
24   const val SPACE_TOMBSTONE = '\u0003'
25 
Stringnull26   fun String.indexOfWhitespaceTombstone() = this.indexOf(SPACE_TOMBSTONE)
27 
28   /**
29    * Google-java-format removes trailing spaces when it emits formatted code, which is a problem for
30    * multiline string literals. We trick it by replacing the last trailing space in such cases with
31    * a tombstone, a character that's unlikely to be used in a regular program. After formatting, we
32    * replace it back to a space.
33    */
34   fun replaceTrailingWhitespaceWithTombstone(s: String): String {
35     return Pattern.compile(" ($)", MULTILINE).matcher(s).replaceAll("$SPACE_TOMBSTONE$1")
36   }
37 
38   /** See [replaceTrailingWhitespaceWithTombstone]. */
replaceTombstoneWithTrailingWhitespacenull39   fun replaceTombstoneWithTrailingWhitespace(s: String): String {
40     return s.replace(SPACE_TOMBSTONE, ' ')
41   }
42 }
43