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Support Chinese punctuation like full-width parentheses #3593
Description
I got an email from a Chinese user explaining that he has to switch the input from Chinese to English in order to type parenthesis in an expression. It would be really convenient for Chinese users if it is possible to use the Chinese full-width variants of characters like parentheses.
This Wikipedia page gives a useful overview: https://en.wikipedia.org/wiki/Chinese_punctuation#Marks_similar_to_European_punctuation. The characters that are relevant for mathjs are:
| Chinese full-width character | Chinese full-width code | English character | Character name |
|---|---|---|---|
， |
U+FF0C | , |
Comma |
、 |
U+3001 | , |
Enumeration comma |
！ |
U+FF01 | ! |
Exclamation mark |
？ |
U+FF1F | ? |
Question mark |
； |
U+FF1B | ; |
Semicolon |
： |
U+FF1A | : |
Colon |
（ |
U+FF08 | ( |
Left parenthesis |
） |
U+FF09 | ) |
Right parenthesis |
［ |
U+FF3B | [ |
Left square bracket |
］ |
U+FF3D | ] |
Right square bracket |
If there is indeed need for this, we can implement support for it in two ways:
- Simple way: in the parse function, write a regular expression which replaces all full-width Chinese characters with their English variant. Or we could just provide two helper functions to replace Chinese full-width characters with their English variants and vice versa.
- More work: similar to functions like
parse.isDigit, introduce functions likeisParenthesisOpenwhich test for the English and Chinese variant of the character. We can also think though how to make sure that stringifying an expression keeps track on the originally used character. I'm not sure if this is worth the added complexity though.
Any thoughts:
Activity
[-]Support Chinese punctuation like full-with parentheses[/-][+]Support Chinese punctuation like full-width parentheses[/+]gwhitney commentedon Nov 12, 2025
josdejong commentedon Nov 12, 2025
👍
You're right we definitely need some refactoring in the parser to make supporting unicode characters easier.
gwhitney commentedon Nov 12, 2025
Also more specifically to this issue, reading the Wikipedia page would suggest that the only Chinese punctuation character we should use as equivalent to the comma in mathjs would be the "Enumeration comma" 、(U+3001), since the only use of comma in mathjs is to separate the items in lists (function arguments, matrix entries, etc.). But if you could verify that point with your Chinese correspondent it would be helpful.
gwhitney commentedon Nov 12, 2025
You raise an important point: should converting a Node to string restore the original Unicode string? I actually think not; I think it is OK for it to produce the ASCII equivalents, because certainly Node-to-string already canonicalizes the expression in other ways (squeezing out excess whitespace, normalizing parenthesization, etc.) But in any case, this question is primarily one relevant to #3557: if the original location is preserved, presumably it's also easy to obtain the original characters used, as needed/desired.
josdejong commentedon Nov 19, 2025
Agree