left-mid-right array

left-right-arr.js

/* [left],  mid [right] */
function leftMidRight () {
  
                this.currentDim = this.dimsMap.get(val)
                this.leftArr = []
                this.rightArr = []
                for (let i = val - 1; i >= val - this.halfSize; --i) {
                    if (i >= 0) {
                    this.leftArr.unshift(i)
                    } else {
                    break
                    }
                }
                for (let i = val + 1; i <= val + this.halfSize; ++i) {
                    if (i < this.maxIndex) {
                        this.rightArr.push(i)
                    } else {
                    break
                    }
                }
                if (this.leftArr.length === this.halfSize && this.rightArr.length === this.halfSize) {
                } else if (this.leftArr.length < this.halfSize) {
                    let missed = this.halfSize - this.leftArr.length
                    let maxRight = this.rightArr[this.rightArr.length - 1]
                    for (let i = 1; i <= missed; i++) {
                        this.rightArr.push(maxRight + i)
                    }
                } else {
                    let missed = this.halfSize - this.rightArr.length
                    let minLeft = this.leftArr[0]
                    for (let i = 1; i <= missed; i++) {
                        this.leftArr.unshift(minLeft - i)
                    }
                }
            
}