gistfile1.js

// 1
// "internationalization"

function abbr (input) {
    const length = input.length
    if (length < 3) {
        return input
    }
    return input[0] + (length - 2) + input[length - 1]
}

const a = 'a'.charCodeAt(0)
const z = a + 25
function isLowerChar (char) {
    const code = char.charCodeAt(0)
    return code >= a && code <= z
}

function abbrPlus (input) {

    const l = input.length
    let ret = ''
    let index = 0
    
    let tmp = ''
    while (index < l) {
        const currentChar = input[index]
        const nextChar = input[index + 1]
        if (isLowerChar(currentChar)) {
            tmp += currentChar
            if (!nextChar || !isLowerChar(nextChar)) {
                ret += abbr(tmp)
                tmp = ''
            }
        } else {
            tmp += currentChar
            if (!nextChar || isLowerChar(nextChar)) {
                ret += tmp
                tmp = ''
            }
        }
        index ++
    }
    return ret
    
}

var input = "%%%jack-jadddne_@@22tom$$"



// 2
// [0, 1, 2, 3, 4, 5, 6, 7]
function bs (arr, target) {
    const l = arr.length

    let left = 0
    let right = l - 1
    while (left <= right) {
        const mid = left + Math.floor((right - left) / 2)
        const midVal = arr[mid]
        if (midVal === target) {
            return mid
        } else if (midVal < target) {
            left = mid + 1
        } else {
            right = mid - 1
        }
    }
    return left
}

var arr = [-5, 0, 1, 2, 3, 4, 5, 6, 7]


// 3
async function fetch (url) { 
    console.log(`fetching... ${url}`); 
    return `content of ${url}`
}

// 

function makeCachedFetch (fetchImpl) {
    const store = new Map 

    return url => {
        const cacheKey = url
        const cachedContent = store.get(cacheKey)
        if (cachedContent) {
            return cachedContent
        }

        const noneCacheContent = fetchImpl(url)
        store.set(cacheKey, noneCacheContent)
        return noneCacheContent
    }
}

const cachedFetch = makeCachedFetch(fetch); 
console.log(cachedFetch('api/search')); 

// fetching..., content of .... 
console.log(cachedFetch('api/search')); 

// content of search 
console.log(cachedFetch('api/home')); 

// fetching... home, content of home 
console.log(cachedFetch('api/search')); 
// content of search