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Diffstat (limited to 'node_modules/nth-check/compile.js')
-rw-r--r-- | node_modules/nth-check/compile.js | 40 |
1 files changed, 0 insertions, 40 deletions
diff --git a/node_modules/nth-check/compile.js b/node_modules/nth-check/compile.js deleted file mode 100644 index 77f2436c8..000000000 --- a/node_modules/nth-check/compile.js +++ /dev/null @@ -1,40 +0,0 @@ -module.exports = compile; - -var BaseFuncs = require("boolbase"), - trueFunc = BaseFuncs.trueFunc, - falseFunc = BaseFuncs.falseFunc; - -/* - returns a function that checks if an elements index matches the given rule - highly optimized to return the fastest solution -*/ -function compile(parsed){ - var a = parsed[0], - b = parsed[1] - 1; - - //when b <= 0, a*n won't be possible for any matches when a < 0 - //besides, the specification says that no element is matched when a and b are 0 - if(b < 0 && a <= 0) return falseFunc; - - //when a is in the range -1..1, it matches any element (so only b is checked) - if(a ===-1) return function(pos){ return pos <= b; }; - if(a === 0) return function(pos){ return pos === b; }; - //when b <= 0 and a === 1, they match any element - if(a === 1) return b < 0 ? trueFunc : function(pos){ return pos >= b; }; - - //when a > 0, modulo can be used to check if there is a match - var bMod = b % a; - if(bMod < 0) bMod += a; - - if(a > 1){ - return function(pos){ - return pos >= b && pos % a === bMod; - }; - } - - a *= -1; //make `a` positive - - return function(pos){ - return pos <= b && pos % a === bMod; - }; -}
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