LeeeeeeM

const event1 = 1;
const event2 = 2;

function trace(event, keypress = () => []) {
  return function trace() {
    return [...keypress(), event];
  }
}

let keypress = trace(event1);

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    function throttle(fn, delay, cxt) {
        var start;
        var timer = null;
        cxt = cxt || this;
        delay = delay || 100;
        return function() {
        	var current = Date.now();
        	clearTimeout(timer);
            if (!start) {
            	start = current;

LeeeeeeM

functino mergeSort(array) {
    if (array.length === 1) {
        return array;
    }
    var middle = Math.floor(array.length / 2);
    var leftArray = array.slice(0, middle);
    var rightArray = array.slice(middle);
    return merge(mergeSort(leftArray), mergeSort(rightArray));
}

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function compose(fn) {
    var fn = [].slice.call(arguments);
    return function(value) {
        while(fn.length > 0) {
            value = fn.pop()(value);
        }
        return value;
    }
}

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function compose(fn) {
    var fnArray = [].slice.call(arguments);
    return function(value) {
        return fnArray.reverse().reduce(function(result, fn) {
            return fn(result)
        }, value);    
    };
}

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function compose(fn) {
    var fnArray = [].slice.call(arguments);
    return fnArray.reverse().reduce(function(fgr, fn) {
        // 因为传入的是一个函数，最终输出一个函数  fgr =====> function
        return function() {
            var args = [].slice.call(arguments);
            return fn(fgr.apply(null, args));
        };
    });
}

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function compose(fn) {
    // 传入的函数大于等于2
    
    var fnArray = [].slice.call(arguments).reverse();
    
    var fn1 = fnArray[0];
    var fn2 = fnArray[1];
    
    if (fnArray.length > 2) {
        var restArray = fnArray.slice(2);

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function reverseArgs(fn) {
    return function reverse(...args) {
        return fn(...args.reverse());
    }
}

function partial(fn, ...preArgs) {
    return function partialApplied(...laterArgs) {
        return fn(...preArgs, ...laterArgs);
    }

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function curry(fn, arity = fn.length) {
    return (function nextCurried(prevArgs) {
        return function curried(...nextArgs) {
            var args = prevArgs.concat(nextArgs);
            if (args.length >= arity) {
                return fn(...args);
            }
            return nextCurried(args);
        }    
    })([]);

LeeeeeeM

// 原始方法
function compose(...fns) {
    return function composed(result) {
        var list = fns.slice();
        while(list.length > 0) {
            result = list.pop()(result);
        }
        return result;
    }
}