4 ms·

You still can use Unicode in comments and string literals. You just can't use non-ASCII characters in identifiers. Unicode in identifiers is just a bad idea.

You still can use Unicode in comments and string literals. You just can't use non-ASCII characters in identifiers. Unicode in identifiers is just a bad idea. 1. It creates a security consideration with confusable identifiers (and lints don't always catch these) 2. It breaks tooling with RTL identifiers 3. It may not render correctly depending on fonts 4. It may be hard to type depending on keyboard layout 5. There really isn't a good reason to use non-ASCII idents anyway

lifthrasiir 5y ago
> 1. It creates a security consideration with confusable identifiers (and lints don't always catch these) O/0 and I/1/l are confusable characters within ASCII. I'm not kidding here, they are actual entries in the Unicode confusables database [1]. But no one wants to remove those characters from identifiers. [1] For example, https://util.unicode.org/UnicodeJsps/confusables.jsp?a=0&r=None https://util.unicode.org/UnicodeJsps/confusables.jsp?a=0&r=N... > 2. It breaks tooling with RTL identifiers It rather unbreaks tooling with no RTL support. > 3. It may not render correctly depending on fonts So does Unicode in comments and string literals. In fact the purported Trojan "attack" was mostly about string literals. So why should they be allowed in strings but disallowed in identifiers? > 4. It may be hard to type depending on keyboard layout Did you know that not every Latin keyboard layout supports a backquote (`)? This was the actual reason that the repr(expr) shortcut got removed from Python 3 [2]. [2] https://mail.python.org/pipermail/python-ideas/2007-January/000054.html https://mail.python.org/pipermail/python-ideas/2007-January/... > 5. There really isn't a good reason to use non-ASCII idents anyway My canonical answer from the experience is that not every programmer who can understand English documentations can easily write and comprehend English in general. For those people having a non-ASCII identifier support is a great relief, as it frees them from choosing "correct" English identifiers. You can disallow them for your project if you want (or conversely, make it an optional feature disabled by default), but they are relevant for someone else.
- mkl 5y ago
  Non-ASCII identifiers can be useful for maths too. E.g. I use λ sometimes, especially in Python where "lambda" is a keyword. (I have AutoHotKey and Espanso hotstrings to make typing such symbols easy.)
- cedilla 5y ago
  > it frees them from choosing "correct" English identifiers Even if you have fluent English skills, sometimes translations just confuse the issue. It's sometimes better to use an untranslated word instead of introducing ambiguity, especially when a term originates from a local law.
  - lifthrasiir 5y ago
    Like CNLabelContactRelationYoungerCousinMothersSiblingsDaughterOrFathersSistersDaughter [1]? :-) You are very much correct. [1] https://news.ycombinator.com/item?id=28712667 https://news.ycombinator.com/item?id=28712667
- __s 5y ago
  > O/0 and I/1/l are confusable characters within ASCII Which is why the first thing I make sure of when looking at programming fonts is how well they differentiate these characters
  - koheripbal 5y ago
    Agreed - this is literally the first thing I check when selecting the editor's font
- josephcsible 5y ago
  > O/0 and I/1/l are confusable characters within ASCII. You're mixing up two different ways that people use the word "confusable": things that look similar in some fonts, versus things that look exactly the same regardless of font. I want the latter to be banned from source files but not the former.
  - lifthrasiir 5y ago
    Confusables are a defined concept in Unicode [1]. And there seems no other good way to define "confusables", since many if not most pairs of characters are distinguishable in some but not all fonts and you can always make a font that distinguishes every code point (I once did that, for example distinguishing Latin-Greek-Cyrillic homoglyphs in subtle ways). [1] https://www.unicode.org/reports/tr39/#Confusable_Detection https://www.unicode.org/reports/tr39/#Confusable_Detection
    - josephcsible 5y ago
      > you can always make a font that distinguishes every code point Even ones like zero-width joiners and right-to-left marks?
      - lifthrasiir 5y ago
        Sure, every graphic code point ;-) But we are talking about Unicode identifiers, and the Unicode recommendation doesn't allow BiDi markers in identifiers and has a provision to limit the use of ZWJ and ZWNJ in them.
Tepix 5y ago
It allows people to code who may not even speak english. That seems more important than your reasons.
- cema 5y ago
  This argument seems to assume that people who do not know English cannot figure out how to use ASCII character set for identifiers. If so, it is rather incorrect. Is there something else here, maybe?
  - Tepix 5y ago
    Yes if they don't speak english they will want to use non ASCII identifiers because that's what non english words use.

lifthrasiir 5y ago

> 1. It creates a security consideration with confusable identifiers (and lints don't always catch these) O/0 and I/1/l are confusable characters within ASCII. I'm not kidding here, they are actual entries in the Unicode confusables database [1]. But no one wants to remove those characters from identifiers. [1] For example, https://util.unicode.org/UnicodeJsps/confusables.jsp?a=0&r=None https://util.unicode.org/UnicodeJsps/confusables.jsp?a=0&r=N... > 2. It breaks tooling with RTL identifiers It rather unbreaks tooling with no RTL support. > 3. It may not render correctly depending on fonts So does Unicode in comments and string literals. In fact the purported Trojan "attack" was mostly about string literals. So why should they be allowed in strings but disallowed in identifiers? > 4. It may be hard to type depending on keyboard layout Did you know that not every Latin keyboard layout supports a backquote (`)? This was the actual reason that the repr(expr) shortcut got removed from Python 3 [2]. [2] https://mail.python.org/pipermail/python-ideas/2007-January/000054.html https://mail.python.org/pipermail/python-ideas/2007-January/... > 5. There really isn't a good reason to use non-ASCII idents anyway My canonical answer from the experience is that not every programmer who can understand English documentations can easily write and comprehend English in general. For those people having a non-ASCII identifier support is a great relief, as it frees them from choosing "correct" English identifiers. You can disallow them for your project if you want (or conversely, make it an optional feature disabled by default), but they are relevant for someone else.

mkl 5y ago
Non-ASCII identifiers can be useful for maths too. E.g. I use λ sometimes, especially in Python where "lambda" is a keyword. (I have AutoHotKey and Espanso hotstrings to make typing such symbols easy.)
cedilla 5y ago
> it frees them from choosing "correct" English identifiers Even if you have fluent English skills, sometimes translations just confuse the issue. It's sometimes better to use an untranslated word instead of introducing ambiguity, especially when a term originates from a local law.
- lifthrasiir 5y ago
  Like CNLabelContactRelationYoungerCousinMothersSiblingsDaughterOrFathersSistersDaughter [1]? :-) You are very much correct. [1] https://news.ycombinator.com/item?id=28712667 https://news.ycombinator.com/item?id=28712667
__s 5y ago
> O/0 and I/1/l are confusable characters within ASCII Which is why the first thing I make sure of when looking at programming fonts is how well they differentiate these characters
- koheripbal 5y ago
  Agreed - this is literally the first thing I check when selecting the editor's font
josephcsible 5y ago
> O/0 and I/1/l are confusable characters within ASCII. You're mixing up two different ways that people use the word "confusable": things that look similar in some fonts, versus things that look exactly the same regardless of font. I want the latter to be banned from source files but not the former.
- lifthrasiir 5y ago
  Confusables are a defined concept in Unicode [1]. And there seems no other good way to define "confusables", since many if not most pairs of characters are distinguishable in some but not all fonts and you can always make a font that distinguishes every code point (I once did that, for example distinguishing Latin-Greek-Cyrillic homoglyphs in subtle ways). [1] https://www.unicode.org/reports/tr39/#Confusable_Detection https://www.unicode.org/reports/tr39/#Confusable_Detection
  - josephcsible 5y ago
    > you can always make a font that distinguishes every code point Even ones like zero-width joiners and right-to-left marks?
    - lifthrasiir 5y ago
      Sure, every graphic code point ;-) But we are talking about Unicode identifiers, and the Unicode recommendation doesn't allow BiDi markers in identifiers and has a provision to limit the use of ZWJ and ZWNJ in them.

Tepix 5y ago

It allows people to code who may not even speak english. That seems more important than your reasons.

cema 5y ago
This argument seems to assume that people who do not know English cannot figure out how to use ASCII character set for identifiers. If so, it is rather incorrect. Is there something else here, maybe?
- Tepix 5y ago
  Yes if they don't speak english they will want to use non ASCII identifiers because that's what non english words use.