Package list node-nth-check / 5aabd6e
Import upstream version 1.0.2+git20181021.77ae802, md5 1c40e046812d51eb823dd171f2af0b01 Debian Janitor 2 years ago
10 changed file(s) with 190 addition(s) and 135 deletion(s). Raw diff Collapse all Expand all
0 node_modules/
00 language: node_js
11 node_js:
2 - 0.8
3 - "0.10"
4 - 0.11
2 - lts/*
0 Copyright (c) Felix Böhm
1 All rights reserved.
2
3 Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
4
5 Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
6
7 Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
8
9 THIS IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS,
10 EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
0 #nth-check [![Build Status](https://travis-ci.org/fb55/nth-check.png)](https://travis-ci.org/fb55/nth-check)
0 # nth-check [![Build Status](https://travis-ci.org/fb55/nth-check.svg)](https://travis-ci.org/fb55/nth-check)
11
22 A performant nth-check parser & compiler.
33
4 ###About
4 ### About
55
66 This module can be used to parse & compile nth-checks, as they are found in CSS 3's `nth-child()` and `nth-last-of-type()`.
77
88 `nth-check` focusses on speed, providing optimized functions for different kinds of nth-child formulas, while still following the [spec](http://www.w3.org/TR/css3-selectors/#nth-child-pseudo).
99
10 ###API
10 ### API
1111
1212 ```js
1313 var nthCheck = require("nth-check");
1414 ```
1515
16 #####`nthCheck(formula)`
16 ##### `nthCheck(formula)`
1717
1818 First parses, then compiles the formula.
1919
20 #####`nthCheck.parse(formula)`
20 ##### `nthCheck.parse(formula)`
2121
2222 Parses the expression, throws a `SyntaxError` if it fails, otherwise returns an array containing two elements.
2323
2727 nthCheck.parse("2n+3") //[2, 3]
2828 ```
2929
30 #####`nthCheck.compile([a, b])`
30 ##### `nthCheck.compile([a, b])`
3131
3232 Takes an array with two elements (as returned by `.parse`) and returns a highly optimized function.
3333
00 module.exports = compile;
11
22 var BaseFuncs = require("boolbase"),
3 trueFunc = BaseFuncs.trueFunc,
3 trueFunc = BaseFuncs.trueFunc,
44 falseFunc = BaseFuncs.falseFunc;
55
66 /*
77 returns a function that checks if an elements index matches the given rule
88 highly optimized to return the fastest solution
99 */
10 function compile(parsed){
11 var a = parsed[0],
12 b = parsed[1] - 1;
10 function compile(parsed) {
11 var a = parsed[0],
12 b = parsed[1] - 1;
1313
14 //when b <= 0, a*n won't be possible for any matches when a < 0
15 //besides, the specification says that no element is matched when a and b are 0
16 if(b < 0 && a <= 0) return falseFunc;
14 //when b <= 0, a*n won't be possible for any matches when a < 0
15 //besides, the specification says that no element is matched when a and b are 0
16 if (b < 0 && a <= 0) return falseFunc;
1717
18 //when a is in the range -1..1, it matches any element (so only b is checked)
19 if(a ===-1) return function(pos){ return pos <= b; };
20 if(a === 0) return function(pos){ return pos === b; };
21 //when b <= 0 and a === 1, they match any element
22 if(a === 1) return b < 0 ? trueFunc : function(pos){ return pos >= b; };
18 //when a is in the range -1..1, it matches any element (so only b is checked)
19 if (a === -1)
20 return function(pos) {
21 return pos <= b;
22 };
23 if (a === 0)
24 return function(pos) {
25 return pos === b;
26 };
27 //when b <= 0 and a === 1, they match any element
28 if (a === 1)
29 return b < 0
30 ? trueFunc
31 : function(pos) {
32 return pos >= b;
33 };
2334
24 //when a > 0, modulo can be used to check if there is a match
25 var bMod = b % a;
26 if(bMod < 0) bMod += a;
35 //when a > 0, modulo can be used to check if there is a match
36 var bMod = b % a;
37 if (bMod < 0) bMod += a;
2738
28 if(a > 1){
29 return function(pos){
30 return pos >= b && pos % a === bMod;
31 };
32 }
39 if (a > 1) {
40 return function(pos) {
41 return pos >= b && pos % a === bMod;
42 };
43 }
3344
34 a *= -1; //make `a` positive
45 a *= -1; //make `a` positive
3546
36 return function(pos){
37 return pos <= b && pos % a === bMod;
38 };
39 }
47 return function(pos) {
48 return pos <= b && pos % a === bMod;
49 };
50 }
00 var parse = require("./parse.js"),
11 compile = require("./compile.js");
22
3 module.exports = function nthCheck(formula){
4 return compile(parse(formula));
3 module.exports = function nthCheck(formula) {
4 return compile(parse(formula));
55 };
66
77 module.exports.parse = parse;
8 module.exports.compile = compile;
8 module.exports.compile = compile;
0 {
1 "name": "nth-check",
2 "version": "1.0.2",
3 "lockfileVersion": 1,
4 "requires": true,
5 "dependencies": {
6 "boolbase": {
7 "version": "1.0.0",
8 "resolved": "https://registry.npmjs.org/boolbase/-/boolbase-1.0.0.tgz",
9 "integrity": "sha1-aN/1++YMUes3cl6p4+0xDcwed24="
10 }
11 }
12 }
00 {
11 "name": "nth-check",
2 "version": "1.0.1",
2 "version": "1.0.2",
33 "description": "performant nth-check parser & compiler",
44 "main": "index.js",
55 "scripts": {
99 "type": "git",
1010 "url": "https://github.com/fb55/nth-check"
1111 },
12 "files": [
13 "compile.js",
14 "index.js",
15 "parse.js"
16 ],
1217 "keywords": [
1318 "nth-child",
1419 "nth",
1520 "css"
1621 ],
1722 "author": "Felix Boehm <me@feedic.com>",
18 "license": "BSD",
23 "license": "BSD-2-Clause",
1924 "bugs": {
2025 "url": "https://github.com/fb55/nth-check/issues"
2126 },
2227 "homepage": "https://github.com/fb55/nth-check",
2328 "dependencies": {
2429 "boolbase": "~1.0.0"
30 },
31 "prettier": {
32 "tabWidth": 4
2533 }
2634 }
77 /*
88 parses a nth-check formula, returns an array of two numbers
99 */
10 function parse(formula){
11 formula = formula.trim().toLowerCase();
10 function parse(formula) {
11 formula = formula.trim().toLowerCase();
1212
13 if(formula === "even"){
14 return [2, 0];
15 } else if(formula === "odd"){
16 return [2, 1];
17 } else {
18 var parsed = formula.match(re_nthElement);
13 if (formula === "even") {
14 return [2, 0];
15 } else if (formula === "odd") {
16 return [2, 1];
17 } else {
18 var parsed = formula.match(re_nthElement);
1919
20 if(!parsed){
21 throw new SyntaxError("n-th rule couldn't be parsed ('" + formula + "')");
22 }
20 if (!parsed) {
21 throw new SyntaxError(
22 "n-th rule couldn't be parsed ('" + formula + "')"
23 );
24 }
2325
24 var a;
26 var a;
2527
26 if(parsed[1]){
27 a = parseInt(parsed[1], 10);
28 if(isNaN(a)){
29 if(parsed[1].charAt(0) === "-") a = -1;
30 else a = 1;
31 }
32 } else a = 0;
28 if (parsed[1]) {
29 a = parseInt(parsed[1], 10);
30 if (isNaN(a)) {
31 if (parsed[1].charAt(0) === "-") a = -1;
32 else a = 1;
33 }
34 } else a = 0;
3335
34 return [
35 a,
36 parsed[3] ? parseInt((parsed[2] || "") + parsed[3], 10) : 0
37 ];
38 }
36 return [a, parsed[3] ? parseInt((parsed[2] || "") + parsed[3], 10) : 0];
37 }
3938 }
00 var nthCheck = require("./"),
11 assert = require("assert");
22
3 var invalid = ["-", "asdf", "2n+-0", "2+0", "- 1n", "-1 n"];
3 var invalid = [
4 "-",
5 "- 1n",
6 "-1 n",
7 "2+0",
8 "2n+-0",
9 "an+b",
10 "asdf",
11 "b",
12 "expr",
13 "odd|even|x"
14 ];
415
5 function parseInvalid(){
6 invalid.forEach(function(formula){
7 assert.throws(function(){
8 nthCheck.parse(formula);
9 },
10 SyntaxError,
11 formula
12 );
13 });
16 function parseInvalid() {
17 invalid.forEach(function(formula) {
18 assert.throws(
19 function() {
20 nthCheck.parse(formula);
21 },
22 SyntaxError,
23 formula
24 );
25 });
1426 }
1527
1628 var valid = {
17 "1": [ 0, 1 ],
18 "2": [ 0, 2 ],
19 "3": [ 0, 3 ],
20 "5": [ 0, 5 ],
21 " 1 ": [ 0, 1 ],
22 " 5 ": [ 0, 5 ],
23 "+2n + 1": [ 2, 1 ],
24 "-1": [ 0, -1 ],
25 "-1n + 3": [ -1, 3 ],
26 "-1n+3": [ -1, 3 ],
27 "-n+2": [ -1, 2 ],
28 "-n+3": [ -1, 3 ],
29 "0n+3": [ 0, 3 ],
30 "1n": [ 1, 0 ],
31 "1n+0": [ 1, 0 ],
32 "2n": [ 2, 0 ],
33 "2n + 1": [ 2, 1 ],
34 "2n+1": [ 2, 1 ],
35 "3n": [ 3, 0 ],
36 "3n+0": [ 3, 0 ],
37 "3n+1": [ 3, 1 ],
38 "3n+2": [ 3, 2 ],
39 "3n+3": [ 3, 3 ],
40 "3n-1": [ 3, -1 ],
41 "3n-2": [ 3, -2 ],
42 "3n-3": [ 3, -3 ],
43 even: [ 2, 0 ],
44 n: [ 1, 0 ],
45 "n+2": [ 1, 2 ],
46 odd: [ 2, 1 ],
29 "1": [0, 1],
30 "2": [0, 2],
31 "3": [0, 3],
32 "5": [0, 5],
33 " 1 ": [0, 1],
34 " 5 ": [0, 5],
35 "+2n + 1": [2, 1],
36 "-1": [0, -1],
37 "-1n + 3": [-1, 3],
38 "-1n+3": [-1, 3],
39 "-n+2": [-1, 2],
40 "-n+3": [-1, 3],
41 "0n+3": [0, 3],
42 "1n": [1, 0],
43 "1n+0": [1, 0],
44 "2n": [2, 0],
45 "2n + 1": [2, 1],
46 "2n+1": [2, 1],
47 "3n": [3, 0],
48 "3n+0": [3, 0],
49 "3n+1": [3, 1],
50 "3n+2": [3, 2],
51 "3n+3": [3, 3],
52 "3n-1": [3, -1],
53 "3n-2": [3, -2],
54 "3n-3": [3, -3],
55 even: [2, 0],
56 n: [1, 0],
57 "n+2": [1, 2],
58 odd: [2, 1],
4759
48 //surprisingly, neither sizzle, qwery or nwmatcher cover these cases
49 "-4n+13": [-4, 13],
50 "-2n + 12": [-2, 12]
60 //surprisingly, neither sizzle, qwery or nwmatcher cover these cases
61 "-4n+13": [-4, 13],
62 "-2n + 12": [-2, 12]
5163 };
5264
53 function parseValid(){
54 Object.keys(valid).forEach(function(formula){
55 assert.deepEqual(nthCheck.parse(formula), valid[formula], formula);
56 });
65 function parseValid() {
66 Object.keys(valid).forEach(function(formula) {
67 assert.deepEqual(nthCheck.parse(formula), valid[formula], formula);
68 });
5769 }
5870
59 function testValid(){
60 Object.keys(valid).forEach(function(formula){
61 testFormula(valid[formula], formula);
62 });
71 function testValid() {
72 Object.keys(valid).forEach(function(formula) {
73 testFormula(valid[formula], formula);
74 });
6375 }
6476
65 var valArray = Array.apply(null, Array(2e3)).map(function(_, i){return i;});
77 var valArray = Array.apply(null, Array(2e3)).map(function(_, i) {
78 return i;
79 });
6680
67 function testFormula(formula, name){
68 var filtered = valArray.filter(nthCheck.compile(formula)),
69 iterated = stupidNth(formula);
81 function testFormula(formula, name) {
82 var filtered = valArray.filter(nthCheck.compile(formula)),
83 iterated = stupidNth(formula);
7084
71 try {
72 assert.deepEqual(filtered, iterated, name);
73 } catch(e){
74 e.expected = JSON.stringify(iterated) + " " + name;
75 e.actual = JSON.stringify(filtered) + " " + name;
76 throw e;
77 }
85 try {
86 assert.deepEqual(filtered, iterated, name);
87 } catch (e) {
88 e.expected = JSON.stringify(iterated) + " " + name;
89 e.actual = JSON.stringify(filtered) + " " + name;
90 throw e;
91 }
7892 }
7993
80 function stupidNth(formula, limit){
81 var a = formula[0],
82 b = formula[1];
94 function stupidNth(formula, limit) {
95 var a = formula[0],
96 b = formula[1];
8397
84 if(a === 0 && b > 0) return [b - 1];
98 if (a === 0 && b > 0) return [b - 1];
8599
86 //taken from qwery
87 return valArray.filter(function(val){
88 for(var i = b, l = valArray.length; ((a > 0) ? (i <= l) : (i >= 1)); i += a){
89 if(val === valArray[i - 1]) return true;
90 }
91 });
100 //taken from qwery
101 return valArray.filter(function(val) {
102 for (var i = b, l = valArray.length; a > 0 ? i <= l : i >= 1; i += a) {
103 if (val === valArray[i - 1]) return true;
104 }
105 });
92106 }
93107
94108 process.stdout.write("- parser");