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NomenCommand指令系统正式启动，该项目是复刻一个我的世界指令系统来做到加快调试或者提供一定的功能性API。

这里是没有开场白的Nomen，NCSelector正是NomenCommand中重要的一部分，其全称为NomenCommandEntitySelector，有关实体选择器的wiki可以参见这里：

minecraft.fandom.com/zh/wiki/%E7%9B%AE%E6%A0%87%E9%80%89%E6%8B%A9%E5%99%A8

那么这里是NCSelector源代码：

class NCSelector {
    constructor(selectorString) {
        if (!selectorString || !selectorString.length) throw new Error('Selector String Required')
        this.data = [];
        let match = /@([a-zA-Z])(?:\[(.*?)\])?/;
        if (selectorString.match(match) && selectorString.match(match)[1]) this.type = selectorString.match(match)[1]
        else { this.type = selectorString; return; }
        if (selectorString.match(match)[2] && selectorString.match(match)[2].length) {
            selectorString.match(match)[2].match(/("[^"]*"|[^,])+/g).forEach(v => {
                this.data.push(this.parseCondition(v));
            })
        };
    }
    parseCondition(condition) {
        let r = condition.match(/([^=!]+)(=!|=)(("[^"]*")|[^,]+)/);
        return { a: r[1].trim(), e: r[2].trim() == '=', b: r[3].trim(), };
    }
    exec(executor) {
        var target;
        if (NCSelector.selectorType[this.type]) target = NCSelector.selectorType[this.type](executor)
        else var target = world.querySelectorAll('player').filter(v => v.player.name == this.type);
        if(this.data.length) this.data.forEach(v => {
            if(v.a=='limit')return
            target = target.filter(r => { return NCSelector.detector[v.a] ? NCSelector.detector[v.a](r, v, executor) : false });
        });
        if (this.data.filter(v => v.a == "limit").length) { target = target.slice(0, parseInt(this.data.filter(v => v.a == "limit")[0].b)) };
        return target;
    }
    addCondition(condition) {
        if (!condition) return;
        this.data.push(this.parseCondition(condition));
        return this.data;
    }
    removeCondition(condition) {
        if (!condition) return;
        this.data = this.data.filter(v => v !== this.parseCondition(condition));
        return this.data;
    }
    static selectorType = {
        'p': (executor) => {
            if (!executor) return [];
            let min = Infinity;
            let minP = null;
            world.querySelectorAll('player').filter(v => v !== executor).forEach(v => {
                if (v.position.distance(executor.position) < min) { minP = v; min = v.position.distance(executor.position); }
            })
            return [minP];
        },
        'a': () => { return world.querySelectorAll('player') },
        'e': () => { return world.querySelectorAll('*').filter(v => !v.hp <= 0) },
        'r': () => { return [world.querySelectorAll('player')[Math.floor(Math.random() * world.querySelectorAll('player').length)]] },
        's': (executor) => { return executor ? [executor] : [] }
    }
    static entityType = {
        'player': (e) => { return e.isPlayer },
    }
    static detector = {
        'name': (target, data) => {
            let result = target.name == data.b.replace(/^"(.*)"$/, '$1')
            return data.e ? result : !result;
        },
        'x': (target, data) => {
            let r = 'x', result;
            if (data.b.startsWith('..') || data.b.endsWith('..')) result = this.compareRelatedNum(target.position[r], data.b)
            else result = Math.floor(target.position[r]) == parseInt(data.b);
            return data.e ? result : !result
        },
        'y': (target, data) => {
            let r = 'y', result;
            if (data.b.startsWith('..') || data.b.endsWith('..')) result = this.compareRelatedNum(target.position[r], data.b)
            else result = Math.floor(target.position[r]) == parseInt(data.b);
            return data.e ? result : !result
        },
        'z': (target, data) => {
            let r = 'z', result;
            if (data.b.startsWith('..') || data.b.endsWith('..')) result = this.compareRelatedNum(target.position[r], data.b)
            else result = Math.floor(target.position[r]) == parseInt(data.b);
            return data.e ? result : !result
        },
        'distance': (target, data, executor) => {
            let result;
            if (data.b.startsWith('..') || data.b.endsWith('..')) result = this.compareRelatedNum(Math.floor(target.position.distance(executor.distance)), data.b)
            else result = Math.floor(target.position.distance(executor.distance)) == parseInt(data.b);
            return data.e ? result : !result
        },
        'tag': (target, data) => {
            let result = target.hasTag(data.b.replace(/^"(.*)"$/, '$1'));
            return data.e ? result : !result;
        },
        'type': (target, data) => {
            let result = this.entityType[data.b.replace(/^"(.*)"$/, '$1')] ? this.entityType[data.b.replace(/^"(.*)"$/, '$1')](target) : false;
            return data.e ? result : !result;
        }
    }
    static compareRelatedNum(num, npnum) {
        if (npnum.startsWith('..')) return num <= Number(npnum.replace(/^\.+|\.+$/g, ""))
        else if (npnum.endsWith('..')) return num >= Number(npnum.replace(/^\.+|\.+$/g, ""));
        return;
    }
    static subscribeDetector(name, handler) {
        if (typeof name == "string" && typeof handler == "function") this.detector[name] = handler;
    }
    static subscribeEntityType(name, handler) {
        if (typeof name == "string" && typeof handler == "function") this.entityType[name] = handler;
    }
}

一些示例：

/**
 * 搜寻一个实体，要求类型为玩家，y坐标大于8
 */
new NCSelector('@e[type=player,y=8..]')

/**
 * 搜寻一个实体，y坐标小于8，x为5
 */
new NCSelector('@e[y=..8,x=5]')

/**
 * 搜寻一个玩家，包含标签NomenQwQ
 */
new NCSelector('@a[tag="NomenQwQ"]')

/**
 * 搜寻一个实体，与执行者的距离大于3
 */
new NCSelector('@e[distance=3..]')

/**
 * 搜寻执行者本身
 */
new NCSelector('@s');

使用方法：

(new NCSelector('@a[tag="NomenQwQ"]')).exec(entity/** @type {Box3Entity} 操作者，即指令发出者，如果为空肯能会导致某些指令静默失败 */) => Box3Entity[] | never[]


同时，你也可以通过subscribeDetector和subscribeEntityType订阅自定义的实体搜索子条目和实体类型（type）