Sunyuan’s homework-2 (finish beginner and ultimate challenges)

final/scope.js

@@ -0,0 +1,147 @@
+const standardMap = require("./standard"); // 注入标准库
+class Scope {
+    constructor(variables, parent, type) {
+        // 解释器运行起来的时候，就需要定义一个全局作用域 global
+        this.type = type; // global || function || block
+        this.parent = parent;
+        this.variables = variables;
+        this.globalScope = standardMap;
+    }
+
+    declare(kind, name, initValue, initialized) {
+        // kind：var / const / let 不同情况定义的位置也不相同
+        switch (kind) {
+            case "var": {
+                if (this.type === "global" && this.find(name)) {
+                    // 查找全局上下文中是否有该变量，如果有则不能更改上下文的值
+                    return;
+                } else if (this.parent.type === "function") {
+                    if (initialized === false && this.find(name)) return; // 如果是函数执行上下文，则只跳过声明提升
+                }
+                if (this.type === "function" || this.type === "global") {
+                    this.variables[name] = {
+                        kind: kind,
+                        value: initValue,
+                        initialized: true,
+                    };
+                } else {
+                    this.parent.declare(kind, name, initValue);
+                }
+                return;
+            }
+            case "const":
+            case "let": {
+                if (this.type === "global" || this.parent.type === "function") {
+                    if (this.find(name))
+                        throw new SyntaxError(
+                            `Identifier '${name}' has already been declared`
+                        );
+                }
+                if (this.variables[name] && this.variables[name].initialized === true) {
+                    throw new SyntaxError(
+                        `Identifier '${name}' has already been declared`
+                    );
+                } else {
+                    this.variables[name] = {
+                        kind: kind,
+                        value: initValue,
+                        initialized: initialized,
+                    };
+                }
+                return;
+            }
+            default: {
+                this.variables[name] = {
+                    kind: kind,
+                    value: initValue,
+                    initialized: initialized,
+                };
+            }
+        }
+        return;
+    }
+
+    get(name) {
+        if (name === null) {
+            return { value: null };
+        } else {
+            if (name === "undefined") {
+                return { value: undefined };
+            } else {
+                if (this.variables && this.variables[name]) {
+                    if (this.parent === undefined) return { value: this.variables[name] };
+                    if (
+                        this.variables[name].kind === "let" ||
+                        this.variables[name].kind === "const"
+                    ) {
+                        if (this.variables[name].initialized === false) {
+                            throw new SyntaxError(
+                                `Cannot access '${name}' before initialization`
+                            );
+                        }
+                    }
+                    return this.variables[name];
+                } else {
+                    if (this.parent !== undefined) {
+                        return this.parent.get(name);
+                    } else {
+                        if (this.globalScope[name]) {
+                            return { value: this.globalScope[name] };
+                        } else if (name === "this") return null;
+                        else if (name === "newTarget") return { value: undefined };
+                        else throw new ReferenceError(`${name} is not defined`);
+                    }
+                }
+            }
+        }
+    }
+
+    set(name, value, property) {
+        if (property) {
+            if (this.variables[name]) {
+                if (name === "module") {
+                    return (this.variables[name][property] = value);
+                } else {
+                    return (this.variables[name].value[property] = value);
+                }
+            } else {
+                if (this.type !== "global" || name === "module") {
+                    return this.parent.set(name, value, property);
+                } else {
+                    this.variables[name] = {
+                        kind: "var",
+                        value: {},
+                    };
+                    return (this.variables[name].value[property] = value);
+                }
+            }
+        } else {
+            if (this.variables[name]) {
+                if (this.variables[name].kind === "const") {
+                    throw new TypeError("Assignment to constant variable");
+                } else {
+                    return (this.variables[name].value = value);
+                }
+            } else {
+                if (this.type !== "global") {
+                    return this.parent.set(name, value);
+                } else {
+                    this.variables[name] = {
+                        kind: "var",
+                        value: value,
+                        initialized: true,
+                    };
+                }
+            }
+        }
+    }
+
+    find(name) {
+        if (this.parent === undefined || this.type === "function") {
+            if (this.variables && this.variables[name]) return true;
+            else return false;
+        } else return this.parent.find(name);
+    }
+}
+
+module.exports = Scope;

final/standard.js

@@ -0,0 +1,73 @@
+let windowObj = null
+let globalObj = null
+
+try {
+    windowObj = window
+} catch (e) { }
+
+try {
+    globalObj = global
+} catch (e) { }
+
+const StandardMap = {
+    // Function properties
+    isFinite: isFinite,
+    isNaN: isNaN,
+    parseFloat: parseFloat,
+    parseInt: parseInt,
+    decodeURI: decodeURI,
+    decodeURIComponent: decodeURIComponent,
+    encodeURI: encodeURI,
+    encodeURIComponent: encodeURIComponent,
+
+    // Fundamental objects
+    Object: Object,
+    Function: Function,
+    Boolean: Boolean,
+    Symbol: Symbol,
+    Error: Error,
+    EvalError: EvalError,
+    RangeError: RangeError,
+    ReferenceError: ReferenceError,
+    SyntaxError: SyntaxError,
+    TypeError: TypeError,
+    URIError: URIError,
+
+    // Numbers and dates
+    Number: Number,
+    Math: Math,
+    Date: Date,
+
+    // Text processing
+    String: String,
+    RegExp: RegExp,
+
+    // Indexed collections
+    Array: Array,
+    Int8Array: Int8Array,
+    Uint8Array: Uint8Array,
+    Uint8ClampedArray: Uint8ClampedArray,
+    Int16Array: Int16Array,
+    Uint16Array: Uint16Array,
+    Int32Array: Int32Array,
+    Uint32Array: Uint32Array,
+    Float32Array: Float32Array,
+    Float64Array: Float64Array,
+
+    // Structured data
+    ArrayBuffer: ArrayBuffer,
+    DataView: DataView,
+    JSON: JSON,
+
+    // // Other
+    window: windowObj,
+    global: globalObj,
+    console: console,
+    setTimeout: setTimeout,
+    clearTimeout: clearTimeout,
+    setInterval: setInterval,
+    clearInterval: clearInterval,
+    Promise: Promise
+}
+
+module.exports = StandardMap

final/test/stack-track.test.js

@@ -4,18 +4,17 @@ const { customEval, Scope } = require('../eval');
 test("not defined", t => {
   const scope = new Scope();
 
-  try {
-    customEval(
-      `function get(){
+  t.throws(
+    function () {
+      customEval(
+        `function get(){
   var a = 123;
   console.log(b);
 }
 
 get();`,
-      scope
-    );
-    t.fail("it should throw an error");
-  } catch (err) {
-    // ignore
-  }
+        scope
+      );
+    }
+  )
 });

homework/1/rename.js

@@ -3,23 +3,41 @@ const astring = require('astring');
 const traverse = require('../../common/traverse');
 
 function transform(root, originName, targetName) {
-  // 遍历所有节点
-  return traverse((node, ctx, next) => {
+    // 遍历所有节点
+    return traverse((node, ctx, next) => {
 
-    // TODO: 作业代码写在这里
-    if (node.type === 'xxx') {
-    }
+        // TODO: 作业代码写在这里
 
-    // 继续往下遍历
-    return next(node, ctx)
-  })(root);
+        const nodeTypeArray = [
+            'FunctionDeclaration',
+            'VariableDeclarator',
+            'MemberExpression',
+            'BinaryExpression'
+        ]
+        const keyTypeArray = [
+            'property',
+            'label',
+            'key'
+        ]
+        if (nodeTypeArray.includes(node.type)) {
+            for (const key in node) {
+                if (keyTypeArray.includes(key)) continue
+                if (node[key].type === 'Identifier' && node[key].name === originName) {
+                    node[key].name = targetName;
+                }
+            }
+        }
+
+        // 继续往下遍历
+        return next(node, ctx)
+    })(root);
 }
 
 function rename(code, originName, targetName) {
-  const ast = acorn.parse(code, {
-    ecmaVersion: 5,
-  })
-  return astring.generate(transform(ast, originName, targetName))
+    const ast = acorn.parse(code, {
+        ecmaVersion: 5,
+    })
+    return astring.generate(transform(ast, originName, targetName))
 }
 
 module.exports = rename