| Strings are **not** required to be UTF-8. Go source code **is** required |
| to be UTF-8. There is a complex path between the two. |
| |
| In short, there are three kinds of strings. They are: |
| |
| 1. the substring of the source that lexes into a string literal. |
| 1. a string literal. |
| 1. a value of type string. |
| |
| Only the first is required to be UTF-8. The second is required to be |
| written in UTF-8, but its contents are interpreted various ways |
| and may encode arbitrary bytes. The third can contain any bytes at |
| all. |
| |
| Try this on: |
| |
| ``` |
| var s string = "\xFF語" |
| ``` |
| Source substring: ` "\xFF語" `, UTF-8 encoded. The data: |
| |
| ``` |
| 22 |
| 5c |
| 78 |
| 46 |
| 46 |
| e8 |
| aa |
| 9e |
| 22 |
| ``` |
| |
| String literal: ` \xFF語 ` (between the quotes). The data: |
| |
| ``` |
| 5c |
| 78 |
| 46 |
| 46 |
| e8 |
| aa |
| 9e |
| ``` |
| |
| The string value (unprintable; this is a UTF-8 stream). The data: |
| |
| ``` |
| ff |
| e8 |
| aa |
| 9e |
| ``` |
| |
| And for record, the characters (code points): |
| ``` |
| <erroneous byte FF, will appear as U+FFFD if you range over the string value> |
| 語 U+8a9e |
| ``` |
