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Diffstat (limited to 'docs/content/en/functions/findRe.md')
| -rw-r--r-- | docs/content/en/functions/findRe.md | 41 |
1 files changed, 15 insertions, 26 deletions
diff --git a/docs/content/en/functions/findRe.md b/docs/content/en/functions/findRe.md index 13d43f896..0b8978ec6 100644 --- a/docs/content/en/functions/findRe.md +++ b/docs/content/en/functions/findRe.md @@ -9,14 +9,25 @@ keywords: [regex] signature: - "findRE PATTERN INPUT [LIMIT]" - "strings.FindRE PATTERN INPUT [LIMIT]" -relatedfuncs: [replaceRE] -aliases: [] +relatedfuncs: [findRESubmatch, replaceRE] --- -By default, the `findRE` function finds all matches. You can limit the number of matches with an optional LIMIT parameter. +By default, `findRE` finds all matches. You can limit the number of matches with an optional LIMIT parameter. When specifying the regular expression, use a raw [string literal] (backticks) instead of an interpreted string literal (double quotes) to simplify the syntax. With an interpreted string literal you must escape backslashes. -The syntax of the regular expression is the same general syntax used by Perl, Python, and other languages. More precisely, it is the syntax accepted by [RE2] except for `\C`. +[string literal]: https://go.dev/ref/spec#String_literals + +This function uses the [RE2] regular expression library. See the [RE2 syntax documentation] for details. Note that the RE2 `\C` escape sequence is not supported. + +[RE2]: https://github.com/google/re2/ +[RE2 syntax documentation]: https://github.com/google/re2/wiki/Syntax/ + +{{% note %}} +The RE2 syntax is a subset of that accepted by [PCRE], roughly speaking, and with various [caveats]. + +[caveats]: https://swtch.com/~rsc/regexp/regexp3.html#caveats +[PCRE]: https://www.pcre.org/ +{{% /note %}} This example returns a slice of all second level headings (`h2` elements) within the rendered `.Content`: @@ -35,25 +46,3 @@ To limit the number of matches to one: {{% note %}} You can write and test your regular expression using [regex101.com](https://regex101.com/). Be sure to select the Go flavor before you begin. {{% /note %}} - -## findRESubmatch - -In Hugo 0.110.0 we added a variant of `findRe` that returns a slice of strings holding the text of the leftmost match of the regular expression in s and the matches, if any, of its subexpressions. - -This: - -```go-html-template -{{ findRESubmatch §§<a\s*href="(.+?)">(.+?)</a>§§ §§<li><a href="#foo">Foo</a></li> <li><a href="#bar">Bar</a></li>§§ | print | safeHTML }} -``` - -Will print: - -``` -[[<a href=\"#foo\">Foo</a> #foo Foo] [<a href=\"#bar\">Bar</a> #bar Bar]] -``` - -{{< new-in "0.110.0" >}} - - -[RE2]: https://github.com/google/re2/wiki/Syntax -[string literal]: https://go.dev/ref/spec#String_literals |