From: Junio C Hamano Date: Fri, 20 May 2016 22:37:26 GMT Subject: Re: [PATCH] userdiff: add built-in pattern for CSS Message-ID: In-Reply-To: <20160520132829.7937-1-william.duclot@ensimag.grenoble-inp.fr> William Duclot writes: > CSS is widely used, motivating it being included as a built-in pattern. > > It must be noted that the word_regex for CSS (i.e. the regex defining > what is a word in the language) does not consider '.' and '#' characters > (in CSS selectors) to be part of the word. This behavior is documented > by the test t/t4018/css-rule. > The logic behind this behavior is the following: identifiers in CSS > selectors are identifiers in a HTML/XML document. Therefore, the '.'/'#' > character are not part of the identifier, but an indicator of the nature > of the identifier in HTML/XML (class or id). Diffing ".class1" and > ".class2" must show that the class name is changed, but we still are > selecting a class. In other words, if "div#foo" changed to "span#bar", word-diff would say that "div changed to span, # didn't change and foo changed to bar". Which makes sense to me. The above is not a request to change anything; just me thinking aloud to see if I agree with the reasoning. > diff --git a/userdiff.c b/userdiff.c > index 6bf2505..0f9cfbe 100644 > --- a/userdiff.c > +++ b/userdiff.c > @@ -148,6 +148,14 @@ PATTERNS("csharp", > "[a-zA-Z_][a-zA-Z0-9_]*" > "|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?" > "|[-+*/<>%&^|=!]=|--|\\+\\+|<<=?|>>=?|&&|\\|\\||::|->"), > +PATTERNS("css", > + "^([^,{}]+)((,[^}]*\\{)|([ \t]*\\{))$", > + /* -- */ > + /* This regex comes from W3C CSS specs. Should theoretically also allow ISO 10646 characters U+00A0 and higher, > + * this not handled in this regex. */ > + "-?[_a-zA-F][-_a-zA-F0-9]*" /* identifiers */ > + "|-?[0-9]+|\\#[0-9a-fA-F]+" /* numbers */ > +), Style: /* * This regex comes from ... * ... * but they are not handled with this regex. */ I wonder if IPATTERN() may make it easier to express the above. Also, a-zA-F (twice seen in "identifiers" section) looks somewhat suspicious. a-fA-F or a-zA-Z I would understand, and I suspect this is a misspelled form of the latter.