View Source Character Set and Source File Encoding
Character Set
The syntax of Erlang tokens allow the use of the full ISO-8859-1 (Latin-1) character set. This is noticeable in the following ways:
- All the Latin-1 printable characters can be used and are shown without the escape backslash convention.
- Unquoted atoms and variables can use all Latin-1 letters.
| Octal | Decimal | Class | |
|---|---|---|---|
| 200 - 237 | 128 - 159 | Control characters | |
| 240 - 277 | 160 - 191 | - ¿ | Punctuation characters |
| 300 - 326 | 192 - 214 | À - Ö | Uppercase letters |
| 327 | 215 | × | Punctuation character |
| 330 - 336 | 216 - 222 | Ø - Þ | Uppercase letters |
| 337 - 366 | 223 - 246 | ß - ö | Lowercase letters |
| 367 | 247 | ÷ | Punctuation character |
| 370 - 377 | 248 - 255 | ø - ÿ | Lowercase letters |
Table: Character Classes
The following tokens are allowed to also use Unicode characters outside of the Latin-1 range:
- String literals. Example:
"√π" - Character literals. Example:
$∑ - Comments in code.
- Quoted atoms. Example:
'μs' - Function names. Example:
's_to_μs'(S) -> S * 1_000_000.
Atoms used as module names, application names, and node names are restricted to the Latin-1 range.
Change
Support for Unicode in string literals, character literals, and comments was introduced in Erlang/OTP R16B. Support for Unicode in atom and function names was introduced in Erlang/OTP 20.
Source File Encoding
The Erlang source file encoding is selected by a comment in one of the first
two lines of the source file. The first string that matches the regular
expression coding\s*[:=]\s*([-a-zA-Z0-9])+ selects the encoding. If the
matching string is an invalid encoding, it is ignored. The valid encodings are
Latin-1 and UTF-8, where the case of the characters can be chosen freely.
The default Erlang source file encoding if no valid coding comment is present
is UTF-8.
Two examples, both selecting Latin-1 as the source file encoding:
%% For this file we have chosen encoding = Latin-1%% -*- coding: latin-1 -*-Change
The default encoding for Erlang source files was changed from Latin-1 to UTF-8 in Erlang/OTP 17.0.