init

2025-12-29 15:30:30 +08:00
commit 6ba2e23a77
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--- a/.gitignore
+++ b/.gitignore
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+node_modules
+dist
--- a/.npmrc
+++ b/.npmrc
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+//npm.xiongxiao.me/:_authToken=${ME_NPM_TOKEN}
+//registry.npmjs.org/:_authToken=${NPM_TOKEN}
--- a/README.md
+++ b/README.md
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+# JS Filter
+
+轻量、易读、可解析、可执行的类 SQL 过滤语法，用于 JavaScript 数组过滤。
+
+## 语法特性
+
+- **WHERE**: 条件过滤
+- **ORDER BY**: 排序
+- **LIMIT**: 限制结果数量
+- **操作符**: `=`, `!=`, `>`, `<`, `>=`, `<=`, `IN`, `CONTAINS`
+- **逻辑**: `AND`, `OR`
+
+## 语法示例
+
+```javascript
+// 基础过滤
+filter(users, "WHERE metadata.type = 'user'");
+
+// 多条件
+filter(users, "WHERE metadata.tags CONTAINS 'premium' AND metadata.region = 'beijing'");
+
+// 排序
+filter(users, "WHERE metadata.type = 'user' ORDER BY metadata.created_at DESC");
+
+// 限制数量
+filter(users, "WHERE metadata.type = 'user' ORDER BY metadata.created_at DESC LIMIT 10");
+
+// IN 操作
+filter(users, "WHERE metadata.region IN ['beijing', 'shanghai']");
+```
+
+## 使用方法
+
+```javascript
+import { filter } from '@kevisual/js-filter';
+
+const users = [
+  {
+    metadata: {
+      tags: ['premium', 'active'],
+      type: 'user',
+      region: 'beijing',
+      created_at: '2024-03-15T10:00:00Z',
+    },
+  },
+  {
+    metadata: {
+      tags: ['free'],
+      type: 'admin',
+      region: 'shanghai',
+      created_at: '2024-01-10T09:00:00Z',
+    },
+  },
+  {
+    metadata: {
+      tags: ['enterprise', 'premium'],
+      type: 'user',
+      region: 'guangzhou',
+      created_at: '2024-04-05T12:00:00Z',
+    },
+  },
+];
+
+// 查找 premium 用户
+const premiumUsers = filter(users, "WHERE metadata.tags CONTAINS 'premium'");
+
+// 查找北京的用户，按创建时间倒序
+const beijingUsers = filter(users, "WHERE metadata.region = 'beijing' ORDER BY metadata.created_at DESC");
+```
--- a/package.json
+++ b/package.json
@@ -0,0 +1,31 @@
+{
+  "name": "@kevisual/js-filter",
+  "version": "0.0.1",
+  "description": "sql like filter for js arrays",
+  "main": "dist/index.js",
+  "types": "dist/index.d.ts",
+  "scripts": {
+    "build": "tsc"
+  },
+  "keywords": [],
+  "author": "abearxiong <xiongxiao@xiongxiao.me> (https://www.xiongxiao.me)",
+  "license": "MIT",
+  "packageManager": "pnpm@10.26.0",
+  "type": "module",
+  "exports": {
+    ".": {
+      "import": "./dist/index.js",
+      "types": "./dist/index.d.ts"
+    }
+  },
+  "files": [
+    "dist",
+    "src"
+  ],
+  "devDependencies": {
+    "typescript": "^5.0.0"
+  },
+  "publishConfig": {
+    "access": "public"
+  }
+}
--- a/src/index.ts
+++ b/src/index.ts
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+type Token = {
+  type: 'WHERE' | 'AND' | 'OR' | 'ORDER' | 'BY' | 'ASC' | 'DESC' | 'LIMIT'
+  | 'EQ' | 'NEQ' | 'GT' | 'LT' | 'GTE' | 'LTE' | 'IN' | 'CONTAINS'
+  | 'IDENTIFIER' | 'STRING' | 'NUMBER' | 'COMMA' | 'LBRACKET' | 'RBRACKET'
+  | 'EOF';
+  value: string;
+  pos: number;
+};
+
+type ASTNode = {
+  type: 'WhereClause' | 'Condition' | 'OrderClause' | 'LimitClause' | 'LogicalOp'
+  | 'Field' | 'Value' | 'InList';
+  left?: ASTNode;
+  right?: ASTNode;
+  field?: string;
+  operator?: string;
+  value?: any;
+  values?: any[];
+  items?: ASTNode[];
+};
+
+class Lexer {
+  private pos = 0;
+  private input: string;
+
+  constructor(input: string) {
+    this.input = input.trim();
+  }
+
+  private skipWhitespace(): void {
+    while (this.pos < this.input.length && /\s/.test(this.input[this.pos])) {
+      this.pos++;
+    }
+  }
+
+  private readString(): string {
+    this.pos++;
+    let result = '';
+    while (this.pos < this.input.length && this.input[this.pos] !== "'") {
+      result += this.input[this.pos];
+      this.pos++;
+    }
+    this.pos++;
+    return result;
+  }
+
+  private readNumber(): string {
+    let result = '';
+    while (this.pos < this.input.length && /[\d.]/.test(this.input[this.pos])) {
+      result += this.input[this.pos];
+      this.pos++;
+    }
+    return result;
+  }
+
+  private readIdentifier(): string {
+    let result = '';
+    while (this.pos < this.input.length && /[\w.]/.test(this.input[this.pos])) {
+      result += this.input[this.pos];
+      this.pos++;
+    }
+    return result;
+  }
+
+  private isKeyword(value: string): boolean {
+    const keywords = ['WHERE', 'AND', 'OR', 'ORDER', 'BY', 'ASC', 'DESC', 'LIMIT', 'IN', 'CONTAINS'];
+    return keywords.includes(value.toUpperCase());
+  }
+
+  nextToken(): Token {
+    this.skipWhitespace();
+
+    if (this.pos >= this.input.length) {
+      return { type: 'EOF', value: '', pos: this.pos };
+    }
+
+    const char = this.input[this.pos];
+
+    if (char === "'") {
+      return { type: 'STRING', value: this.readString(), pos: this.pos };
+    }
+
+    if (/\d/.test(char)) {
+      return { type: 'NUMBER', value: this.readNumber(), pos: this.pos };
+    }
+
+    if (char === ',') {
+      this.pos++;
+      return { type: 'COMMA', value: ',', pos: this.pos };
+    }
+
+    if (char === '[') {
+      this.pos++;
+      return { type: 'LBRACKET', value: '[', pos: this.pos };
+    }
+
+    if (char === ']') {
+      this.pos++;
+      return { type: 'RBRACKET', value: ']', pos: this.pos };
+    }
+
+    if (/[=<>!]/.test(char)) {
+      this.pos++;
+      if (char === '=' && this.pos < this.input.length && this.input[this.pos] === '=') {
+        this.pos++;
+        return { type: 'EQ', value: '==', pos: this.pos };
+      }
+      if (char === '!' && this.pos < this.input.length && this.input[this.pos] === '=') {
+        this.pos++;
+        return { type: 'NEQ', value: '!=', pos: this.pos };
+      }
+      if (char === '>') {
+        if (this.pos < this.input.length && this.input[this.pos] === '=') {
+          this.pos++;
+          return { type: 'GTE', value: '>=', pos: this.pos };
+        }
+        return { type: 'GT', value: '>', pos: this.pos };
+      }
+      if (char === '<') {
+        if (this.pos < this.input.length && this.input[this.pos] === '=') {
+          this.pos++;
+          return { type: 'LTE', value: '<=', pos: this.pos };
+        }
+        return { type: 'LT', value: '<', pos: this.pos };
+      }
+      return { type: 'EQ', value: char, pos: this.pos };
+    }
+
+    const identifier = this.readIdentifier();
+    const upperIdentifier = identifier.toUpperCase();
+    const keywords: Record<string, Token['type']> = {
+      'WHERE': 'WHERE',
+      'AND': 'AND',
+      'OR': 'OR',
+      'ORDER': 'ORDER',
+      'BY': 'BY',
+      'ASC': 'ASC',
+      'DESC': 'DESC',
+      'LIMIT': 'LIMIT',
+      'IN': 'IN',
+      'CONTAINS': 'CONTAINS'
+    };
+
+    if (keywords[upperIdentifier]) {
+      return { type: keywords[upperIdentifier], value: upperIdentifier, pos: this.pos };
+    }
+
+    return { type: 'IDENTIFIER', value: identifier, pos: this.pos };
+  }
+}
+
+class Parser {
+  private lexer: Lexer;
+  private currentToken: Token;
+
+  constructor(lexer: Lexer) {
+    this.lexer = lexer;
+    this.currentToken = this.lexer.nextToken();
+  }
+
+  private eat(type: Token['type']): void {
+    if (this.currentToken.type === type) {
+      this.currentToken = this.lexer.nextToken();
+    } else {
+      throw new Error(`Expected ${type}, got ${this.currentToken.type}`);
+    }
+  }
+
+  parse(): ASTNode[] {
+    const statements: ASTNode[] = [];
+
+    if (this.currentToken.type === 'WHERE') {
+      statements.push(this.parseWhere());
+    }
+
+    if (this.currentToken.type === 'ORDER') {
+      statements.push(this.parseOrder());
+    }
+
+    if (this.currentToken.type === 'LIMIT') {
+      statements.push(this.parseLimit());
+    }
+
+    return statements;
+  }
+
+  private parseWhere(): ASTNode {
+    this.eat('WHERE');
+    return { type: 'WhereClause', left: this.parseCondition() };
+  }
+
+  private parseCondition(): ASTNode {
+    let left = this.parseExpression();
+
+    while (this.currentToken.type === 'AND' || this.currentToken.type === 'OR') {
+      const op = this.currentToken.type;
+      this.eat(op);
+      const right = this.parseExpression();
+      left = { type: 'LogicalOp', left, right, operator: op };
+    }
+
+    return left;
+  }
+
+  private parseExpression(): ASTNode {
+    const field = this.currentToken.value;
+    this.eat('IDENTIFIER');
+
+    let operator: string;
+    let value: any;
+
+    if (this.currentToken.type === 'CONTAINS') {
+      operator = 'CONTAINS';
+      this.eat('CONTAINS');
+      value = this.parseValue();
+    } else if (this.currentToken.type === 'IN') {
+      operator = 'IN';
+      this.eat('IN');
+      value = this.parseInList();
+    } else {
+      const opType = this.currentToken.type;
+      this.eat(opType);
+      operator = opType;
+      value = this.parseValue();
+    }
+
+    return { type: 'Condition', field, operator, value };
+  }
+
+  private parseInList(): any[] {
+    this.eat('LBRACKET');
+    const values: any[] = [];
+
+    while (this.currentToken.type !== 'RBRACKET') {
+      const node = this.parseValue();
+      values.push(node.value);
+
+      if (this.currentToken.type === 'COMMA') {
+        this.eat('COMMA');
+      }
+    }
+
+    this.eat('RBRACKET');
+    return values;
+  }
+
+  private parseValue(): ASTNode {
+    if (this.currentToken.type === 'STRING') {
+      const value = this.currentToken.value;
+      this.eat('STRING');
+      return { type: 'Value', value };
+    }
+    if (this.currentToken.type === 'NUMBER') {
+      const value = parseFloat(this.currentToken.value);
+      this.eat('NUMBER');
+      return { type: 'Value', value };
+    }
+    throw new Error(`Expected value, got ${this.currentToken.type}`);
+  }
+
+  private parseOrder(): ASTNode {
+    this.eat('ORDER');
+    this.eat('BY');
+    const field = this.currentToken.value;
+    this.eat('IDENTIFIER');
+    let direction = 'ASC';
+    if (this.currentToken.type === 'ASC' || this.currentToken.type === 'DESC') {
+      direction = this.currentToken.value;
+      this.eat(this.currentToken.type);
+    }
+    return { type: 'OrderClause', field, value: direction };
+  }
+
+  private parseLimit(): ASTNode {
+    this.eat('LIMIT');
+    const value = parseFloat(this.currentToken.value);
+    this.eat('NUMBER');
+    return { type: 'LimitClause', value };
+  }
+}
+
+class Executor {
+  private getValueByPath(obj: any, path: string): any {
+    return path.split('.').reduce((acc, part) => acc?.[part], obj);
+  }
+
+  evaluateCondition(node: ASTNode, item: any): boolean {
+    if (node.type === 'Condition') {
+      const fieldValue = this.getValueByPath(item, node.field!);
+      const { operator, value } = node;
+      const actualValue = value?.type === 'Value' ? value.value : value;
+
+      switch (operator) {
+        case 'EQ':
+          return fieldValue === actualValue;
+        case 'NEQ':
+          return fieldValue !== actualValue;
+        case 'GT':
+          return fieldValue > actualValue;
+        case 'LT':
+          return fieldValue < actualValue;
+        case 'GTE':
+          return fieldValue >= actualValue;
+        case 'LTE':
+          return fieldValue <= actualValue;
+        case 'IN':
+          return Array.isArray(actualValue) && actualValue.includes(fieldValue);
+        case 'CONTAINS':
+          return Array.isArray(fieldValue) && fieldValue.includes(actualValue);
+        default:
+          return false;
+      }
+    }
+
+    if (node.type === 'LogicalOp') {
+      const leftResult = this.evaluateCondition(node.left!, item);
+      const rightResult = this.evaluateCondition(node.right!, item);
+
+      return node.operator === 'AND'
+        ? leftResult && rightResult
+        : leftResult || rightResult;
+    }
+
+    return true;
+  }
+
+  execute(statements: ASTNode[], data: any[]): any[] {
+    let result = [...data];
+
+    for (const stmt of statements) {
+      if (stmt.type === 'WhereClause') {
+        result = result.filter(item => this.evaluateCondition(stmt.left!, item));
+      } else if (stmt.type === 'OrderClause') {
+        const field = stmt.field!;
+        const direction = stmt.value;
+        result.sort((a, b) => {
+          const aVal = this.getValueByPath(a, field);
+          const bVal = this.getValueByPath(b, field);
+          if (aVal === bVal) return 0;
+          const cmp = aVal > bVal ? 1 : -1;
+          return direction === 'ASC' ? cmp : -cmp;
+        });
+      } else if (stmt.type === 'LimitClause') {
+        result = result.slice(0, stmt.value);
+      }
+    }
+
+    return result;
+  }
+}
+
+export function createFilter(query: string): (item: any) => boolean {
+  const lexer = new Lexer(query);
+  const parser = new Parser(lexer);
+  const ast = parser.parse();
+  const executor = new Executor();
+
+  const whereClause = ast.find(stmt => stmt.type === 'WhereClause');
+
+  if (!whereClause) {
+    return () => true;
+  }
+
+  return (item: any) => executor.evaluateCondition(whereClause.left!, item);
+}
+
+export function filter(data: any[], query: string): any[] {
+  const lexer = new Lexer(query);
+  const parser = new Parser(lexer);
+  const ast = parser.parse();
+  const executor = new Executor();
+  return executor.execute(ast, data);
+}
+
+export function parse(query: string): ASTNode[] {
+  const lexer = new Lexer(query);
+  const parser = new Parser(lexer);
+  return parser.parse();
+}
+
+
--- a/test/example.ts
+++ b/test/example.ts
@@ -0,0 +1,55 @@
+import { filter } from '../src/index.ts';
+
+const users = [
+  {
+    metadata: {
+      tags: ['premium', 'active'],
+      type: 'user',
+      region: 'beijing',
+      created_at: '2024-03-15T10:00:00Z'
+    }
+  },
+  {
+    metadata: {
+      tags: ['free'],
+      type: 'admin',
+      region: 'shanghai',
+      created_at: '2024-01-10T09:00:00Z'
+    }
+  },
+  {
+    metadata: {
+      tags: ['enterprise', 'premium'],
+      type: 'user',
+      region: 'guangzhou',
+      created_at: '2024-04-05T12:00:00Z'
+    }
+  }
+];
+
+console.log('=== 方式1: users.filter(createFilter("...")) ===');
+
+console.log('\n=== premium 用户 ===');
+console.log(filter(users, "WHERE metadata.tags CONTAINS 'premium'"));
+
+console.log('\n=== 北京用户 ===');
+console.log(filter(users, "WHERE metadata.region = 'beijing'"));
+
+console.log('\n=== user 类型用户 ===');
+console.log(filter(users, "WHERE metadata.type = 'user'"));
+
+console.log('\n=== premium 且 user 类型 ===');
+console.log(filter(users, "WHERE metadata.tags CONTAINS 'premium' AND metadata.type = 'user'"));
+
+console.log('\n=== 北京或上海用户 ===');
+console.log(filter(users, "WHERE metadata.region IN ['beijing', 'shanghai']"));
+
+console.log('\n=== 方式2: filter(users, "...") (支持 ORDER BY 和 LIMIT) ===');
+
+console.log('\n=== 北京用户，按时间倒序 ===');
+console.log(filter(users, "WHERE metadata.region = 'beijing' ORDER BY metadata.created_at DESC"));
+
+console.log('\n=== 前2个用户，按时间倒序 ===');
+const limitResult = filter(users, "ORDER BY metadata.created_at DESC LIMIT 2");
+console.log('Limit result length:', limitResult.length);
+console.log(limitResult);
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -0,0 +1,17 @@
+{
+  "compilerOptions": {
+    "target": "ES2020",
+    "module": "ES2020",
+    "moduleResolution": "node",
+    "lib": ["ES2020"],
+    "declaration": true,
+    "outDir": "./dist",
+    "rootDir": "./src",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true
+  },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules", "dist"]
+}