Re: [PATCH] userdiff: add builtin driver for kotlin language
- From
Johannes Sixt <j6t@kdbg.org>
- Date
- Mar 4, 2022, 13:59 UTC
- Message-ID
- <674822c0-583c-a5ca-6528-751777a24f99@kdbg.org>
- In-Reply-To
- <90596af6-0158-beb9-7fa7-9237e7cff4fb@gmail.com>
Am 04.03.22 um 13:28 schrieb Jaydeep Das:
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> On 3/4/22 01:34, Johannes Sixt wrote: >> Am 03.03.22 um 12:41 schrieb Jaydeep Das: >>> How about modifying the number match regex to: >>> >>> `[0-9._]+([Ee][-+]?[0-9]+)?[fFlLuU]*[^a-zA-Z]` ? >>> >>> The `[^a-zA-Z]` in the end would make sure to not match >>> the `.F` in `X.Find`. > >> No, you cannot do that, because then in X.u+1 you have three tokens X >> .u+ 1, which you do not want, either. > > If X is an integer here, then
No, I mean X literally, i.e., an identifier.
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> > In C/C++ 2.f is equivalent to 2.000000 > However in Kotlin 2.f is invalid syntax. 2.0f is valid. > > So is implementing a proper regex for invalid syntax really > necessary?
No, that's not necessary. It can be assumed that invalid syntax does not occur. For this reason...
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>> Have a look at the regex in the cpp driver. I think we need something >> like this: >> >> /* integers floatingpoint numbers */ >> "|[0-9][0-9_.]*([Ee][*-]?[0-9]+)?[FfLl]*"
... I propose this loose [0-9_.]* after the first digit, even though it would match "9.8_7._65"; we can assume that this invalid token will not occur.
BTW, make that [FfLlUl] near the end.
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>> /* floatingpoint numbers that begin with a decimal point */ >> "|[.][0-9][0-9_]*([Ee][*-]?[0-9]+)?[FfLl]*" > > >> Drop the second option if numbers such as .5 are invalid syntax in >> Kotlin. > .5 is valid syntax in Kotlin.
OK, then we need this second branch, which ensures that there is a digit after the fullstop.
-- Hannes