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| author | ruki <waruqi@gmail.com> | 2018-11-08 00:38:48 +0800 |
|---|---|---|
| committer | ruki <waruqi@gmail.com> | 2018-11-07 21:53:09 +0800 |
| commit | 26105034da4fcce7ac883c899d781f016559310d (patch) | |
| tree | c459a5dc4e3aa0972d9919033ece511ce76dd129 /node_modules/nth-check/parse.js | |
| parent | 2c77f00f1a7ecb6c8192f9c16d3b2001b254a107 (diff) | |
| download | xmake-docs-26105034da4fcce7ac883c899d781f016559310d.tar.gz xmake-docs-26105034da4fcce7ac883c899d781f016559310d.zip | |
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Diffstat (limited to 'node_modules/nth-check/parse.js')
| -rw-r--r-- | node_modules/nth-check/parse.js | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/node_modules/nth-check/parse.js b/node_modules/nth-check/parse.js new file mode 100644 index 00000000..5302951f --- /dev/null +++ b/node_modules/nth-check/parse.js @@ -0,0 +1,40 @@ +module.exports = parse; + +//following http://www.w3.org/TR/css3-selectors/#nth-child-pseudo + +//[ ['-'|'+']? INTEGER? {N} [ S* ['-'|'+'] S* INTEGER ]? +var re_nthElement = /^([+\-]?\d*n)?\s*(?:([+\-]?)\s*(\d+))?$/; + +/* + parses a nth-check formula, returns an array of two numbers +*/ +function parse(formula){ + formula = formula.trim().toLowerCase(); + + if(formula === "even"){ + return [2, 0]; + } else if(formula === "odd"){ + return [2, 1]; + } else { + var parsed = formula.match(re_nthElement); + + if(!parsed){ + throw new SyntaxError("n-th rule couldn't be parsed ('" + formula + "')"); + } + + var a; + + if(parsed[1]){ + a = parseInt(parsed[1], 10); + if(isNaN(a)){ + if(parsed[1].charAt(0) === "-") a = -1; + else a = 1; + } + } else a = 0; + + return [ + a, + parsed[3] ? parseInt((parsed[2] || "") + parsed[3], 10) : 0 + ]; + } +} |
