Re: [PATCH] userdiff: add builtin driver for kotlin language

From: Jaydeep Das <jaydeepjd.8914@gmail.com>
Date: Mar 3, 2022, 11:41 UTC
Message-ID: <76d46b15-f6c0-b8da-87e8-a992047b9a6a@gmail.com>
In-Reply-To: <fe93dfb2-7c0d-11cb-09a0-9ccc7fcc2507@kdbg.org>

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`.

Additionally, we can add another regex for matching just the method calls:

`[.][a-zA-Z()0-9]+`

Both of these changes would make word_regex match 2 tokens in X.Find() : X and .Find() (Here X can be any valid identifier name)

> How many tokens will the word-regex find in the expression X.e+200UL?
> .e+200UL is a single token. > It's most easily fixed by requiring a digit before the fullstop. But if
> floatingpoint numbers can begin with a fullstop, then we need a second
> expression that requires a digit after a leading fullstop.

But that syntax would be wrong. I tried making a condition like you said, but it always ended up breaking something else(like breaking 2.e+200UL into 2, .e, + and 200UL)

Also, I realized I did a bit of mistake in the identifier regex. Both _abc and __abc are valid identifiers. _3432, __3232 are valid identifiers too.(not numbers)

The previous regex matched only one `_`, so in the next patch, I plan to implement the following regex:

Identifier: `([_]*[a-zA-Z]|[_]+[0-9]+)[a-zA-Z0-9_]*`

Numbers: `[0-9_.]+([Ee][-+]?[0-9]+)?[fFlLuU]*[^a-zA-Z]`
(It makes sure that in X.Find, .F is not matched )

Additionally, An extra regex for method calls:

`[.][a-zA-Z()0-9]+`

What do you think?

Thanks, Jaydeep.