{"id":1183,"date":"2020-03-12T17:57:51","date_gmt":"2020-03-12T09:57:51","guid":{"rendered":"http:\/\/www.xiaosuigu.top\/?p=1183"},"modified":"2020-03-12T17:57:51","modified_gmt":"2020-03-12T09:57:51","slug":"ast%e5%8f%8d%e6%b7%b7%e6%b7%86","status":"publish","type":"post","link":"https:\/\/www.xiaosuigu.top\/index.php\/2020\/03\/12\/ast%e5%8f%8d%e6%b7%b7%e6%b7%86\/","title":{"rendered":"AST\u53cd\u6df7\u6dc6"},"content":{"rendered":"\n<p><strong>AST\u7b80\u4ecb\uff1a<\/strong><a href=\"https:\/\/blog.csdn.net\/qq_39200185\/article\/details\/121203676\">\u539f\u7406\u89e3\u6790\uff1aJS \u4ee3\u7801\u662f\u5982\u4f55\u88ab\u6d4f\u89c8\u5668\u5f15\u64ce\u7f16\u8bd1\u3001\u6267\u884c\u7684\uff1f_js \u7f16\u8bd1\u89e3\u6790?.-CSDN\u535a\u5ba2<\/a><\/p>\n\n\n\n<p><strong>AST\u5728\u7ebf\u89e3\u6790<\/strong>\uff1a<a href=\"https:\/\/astexplorer.net\/\">AST explorer<\/a>   \u5de6\u8fb9\u662f\u4ee3\u7801\u53f3\u8fb9\u662f\u6811\u72b6\u7ed3\u6784\uff0c\u4e0a\u65b9\u9009\u62e9js\u548c@bable\/parser<\/p>\n\n\n\n<p><strong>JS\u5b9e\u73b0<\/strong>\uff1a\u5b89\u88c5\u5305<code>npm install @babel\/core --save<\/code> <\/p>\n\n\n\n<p><strong>Babel\u5b98\u7f51<\/strong>\uff1a<a href=\"https:\/\/www.babeljs.cn\/docs\/\">Babel \u662f\u4ec0\u4e48\uff1f \u00b7 Babel \u4e2d\u6587\u6587\u6863 | Babel\u4e2d\u6587\u7f51 (babeljs.cn)<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">1.  \u8282\u70b9\u6811\u5b57\u6bb5\u89e3\u91ca<\/h3>\n\n\n\n<ol class=\"wp-block-list\"><li>type: \u8868\u793a\u5f53\u524d\u8282\u70b9\u7684\u7c7b\u578b\uff0c\u6211\u4eec\u5e38\u7528\u7684\u7c7b\u578b\u5224\u65ad\u65b9\u6cd5,\u5c31\u662f\u5224\u65ad\u5f53\u524d\u7684\u8282\u70b9\u662f\u5426\u4e3a\u67d0\u4e2a\u7c7b\u578b\u3002<\/li><li>start: \u8868\u793a\u5f53\u524d\u8282\u70b9\u7684\u8d77\u59cb\u4f4d\u3002<\/li><li>end: \u8868\u793a\u5f53\u524d\u8282\u70b9\u7684\u672b\u5c3e\u3002<\/li><li>loc : \u8868\u793a\u5f53\u524d\u8282\u70b9\u6240\u5728\u7684\u884c\u5217\u4f4d\u7f6e\uff0c\u91cc\u9762\u4e5f\u6709start\u4e0eend\u8282\u70b9\uff0c\u8fd9\u91cc\u7684start\u4e0e\u4e0a\u9762\u7684start\u662f\u4e0d\u540c<br>\u7684\uff0c\u8fd9\u91cc\u7684start\u662f\u8868\u793a\u8282\u70b9\u6240\u5728\u8d77\u59cb\u7684\u884c\u5217\u4f4d\u3002\u7f6e\uff0c\u800cend\u8868\u793a\u7684\u662f\u8282\u70b9\u6240\u5728\u672b\u5c3e\u7684\u884c\u5217\u4f4d\u7f6e\u3002<\/li><li>errors:\u662fFile\u8282\u70b9\u6240\u7279\u6709\u7684\u5c5e\u6027\uff0c\u53ef\u4ee5\u4e0d\u7528\u7406\u4f1a\u3002<\/li><li>program:\u5305\u542b\u6574\u4e2a\u6e90\u4ee3\u7801\uff0c\u4e0d\u5305\u542b\u6ce8\u91ca\u8282\u70b9\u3002<\/li><li>comments:\u6e90\u4ee3\u7801\u4e2d\u6240\u6709\u7684\u6ce8\u91ca\u4f1a\u5728\u8fd9\u91cc\u663e\u793a<\/li><\/ol>\n\n\n\n<figure class=\"wp-block-image size-large\"><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='http:\/\/www.xiaosuigu.top\/wp-content\/uploads\/2024\/03\/13103695-23f7a34b17a3a28c.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"http:\/\/www.xiaosuigu.top\/wp-content\/uploads\/2024\/03\/13103695-23f7a34b17a3a28c.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" class=\"wp-image-1185\"\/><\/div><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">2. Babel\u4f7f\u7528<\/h3>\n\n\n\n<ol class=\"wp-block-list\"><li>@babel\/core \uff1aBabel \u7f16\u8bd1\u5668\u672c\u8eab\uff0c\u63d0\u4f9b\u4e86 babel \u7684\u7f16\u8bd1 API\uff1b<\/li><li>@babel\/parser \uff1a\u5c06 JavaScript \u4ee3\u7801\u89e3\u6790\u6210 AST \u8bed\u6cd5\u6811\uff1b<\/li><li>@babel\/traverse \uff1a\u904d\u5386\u3001\u4fee\u6539 AST \u8bed\u6cd5\u6811\u7684\u5404\u4e2a\u8282\u70b9\uff1b<\/li><li>@babel\/generator \uff1a\u5c06 AST \u8fd8\u539f\u6210 JavaScript \u4ee3\u7801\uff1b<\/li><li>@babel\/types \uff1a\u5224\u65ad\u3001\u9a8c\u8bc1\u8282\u70b9\u7684\u7c7b\u578b\u3001\u6784\u5efa\u65b0 AST \u8282\u70b9\u7b49\u3002<\/li><\/ol>\n\n\n\n<h4 class=\"wp-block-heading\">2.1 parser\u4f7f\u7528<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>const parse = require('@babel\/parser')\n\njscode = `var a = \"\\u0068\\u0065\\u006c\\u006c\\u006f\\u002c\\u0041\\u0053\\u0054\";`\nlet ast = parse.parse(jscode)\nconsole.log(JSON.stringify(ast, null, '\\t'));<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\">2.2 traverse\u4f7f\u7528<\/h4>\n\n\n\n<ul class=\"wp-block-list\"><li>path.node :\u8868\u793a\u5f53\u524dpath\u4e0b\u7684node\u8282\u70b9<\/li><li>path.toString() :\u5f53\u524d\u8def\u5f84\u6240\u5bf9\u5e94\u7684\u6e90\u4ee3\u7801<\/li><li>path.parentPath :\u7528\u4e8e\u83b7\u53d6\u5f53\u524dpath\u4e0b\u7684\u7236path\uff0c\u591a\u7528\u4e8e\u5224\u65ad\u8282\u70b9\u7c7b\u578b<\/li><li>path.container :\u7528\u4e8e\u83b7\u53d6\u5f53\u524dpath\u4e0b\u7684\u6240\u6709\u5144\u5f1f\u8282\u70b9(\u5305\u62ec\u81ea\u8eab)<\/li><li>path.type :\u83b7\u53d6\u5f53\u524d\u8282\u70b9\u7c7b\u578b<\/li><li>path.get(&#8221;) :\u83b7\u53d6path\u7684\u5b50\u8def\u5f84<\/li><li>path.replaceWith(newNode)\uff1a(\u5355)\u8282\u70b9\u66ff\u6362\u51fd\u6570<\/li><li>path.replaceWithMultiple(ArrayNode);\u591a\u8282\u70b9\u66ff\u6362\u51fd\u6570<\/li><\/ul>\n\n\n\n<div  class='collapse-block shadow-sm collapse-block-transparent collapsed hide-border-left'><div class='collapse-block-title'><span class='collapse-block-title-inner'>\u7b80\u5355\u62fc\u63a5\u8fd8\u539f<\/span><i class='collapse-icon fa fa-angle-down'><\/i><\/div><div class='collapse-block-body' style='display:none;'><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>const parse = require('@babel\/parser')\nconst {types} = require(\"@babel\/core\");\nconst traverse = require('@babel\/traverse').default\nconst generator = require(\"@babel\/generator\").default;\n\njscode = `var b = 1 + 2;\nvar c = \"coo\" + \"kie\";\nvar a = 1+1;\nvar c = 3;`\nlet ast = parse.parse(jscode)\n\n\nconst vis = {\n    BinaryExpression(path) {\n        let {left, operator, right} = path.node;\n        \/\/ \u5982\u679c\u4e24\u8fb9\u662f\u6570\u5b57\u4e14\u662f\u52a0\u53f7\u5c31\u8fdb\u884c\u76f8\u52a0\n        if (types.isNumericLiteral(left) &amp;&amp; types.isNumericLiteral(right) &amp;&amp; operator == '+') {\n            value = left.value + right.value\n            path.replaceWith(types.valueToNode(value))\n        }\n        if (types.isStringLiteral(left) &amp;&amp; types.isStringLiteral(right) &amp;&amp; operator == '+') {\n            value = left.value + right.value\n            path.replaceWith(types.valueToNode(value))\n        }\n    }\n}\n\ntraverse(ast, vis)\n\nconst {code} = generator(ast)\nconsole.log(code);\n<\/code><\/pre>\n\n\n\n<p><\/div><\/div>\n\n\n\n<div  class='collapse-block shadow-sm collapse-block-transparent collapsed hide-border-left'><div class='collapse-block-title'><span class='collapse-block-title-inner'>replaceWithMultiple\u7684\u4f7f\u7528<\/span><i class='collapse-icon fa fa-angle-down'><\/i><\/div><div class='collapse-block-body' style='display:none;'><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>const parse = require('@babel\/parser')\nconst {types} = require(\"@babel\/core\");\nconst traverse = require('@babel\/traverse').default\nconst generator = require(\"@babel\/generator\").default;\n\njscode = `var arr =  '3,4,0,5,1,2'&#091;'split'](',')`\nlet ast = parse.parse(jscode)\n\n\nconst vis = {\n    CallExpression(path) {\n        let {callee, arguments} = path.node\n        let object = callee.object.value;\n        let property = callee.property.value;\n        let argument = arguments&#091;0].value;\n        array = object&#091;property](argument)\n        path.replaceWithMultiple(types.valueToNode(array))\n    }\n}\n\ntraverse(ast, vis)\n\nconst {code} = generator(ast)\nconsole.log(code);\n<\/code><\/pre>\n\n\n\n<p><\/div><\/div>\n\n\n\n<div  class='collapse-block shadow-sm collapse-block-transparent collapsed hide-border-left'><div class='collapse-block-title'><span class='collapse-block-title-inner'>\u81ea\u6267\u884c\u65b9\u6cd5\u8fd8\u539f<\/span><i class='collapse-icon fa fa-angle-down'><\/i><\/div><div class='collapse-block-body' style='display:none;'><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>const parse = require('@babel\/parser')\nconst {types} = require(\"@babel\/core\");\nconst traverse = require('@babel\/traverse').default\nconst generator = require(\"@babel\/generator\").default;\n\njscode = `!(function (){\n console.log('123')\n })`\nlet ast = parse.parse(jscode)\n\n\nconst vis = {\n    UnaryExpression(path) {\n        let {argument} = path.node;\n        if (!types.isFunctionExpression(argument)) {\n            return;\n        }\n        let {body, id, params} = argument;\n        if (id != null || params.length != 0) {\n            return;\n        }\n        path.replaceWithMultiple(body.body)\n    }\n}\n\ntraverse(ast, vis)\n\nconst {code} = generator(ast)\nconsole.log(code);\n<\/code><\/pre>\n\n\n\n<p><\/div><\/div>\n\n\n\n<div  class='collapse-block shadow-sm collapse-block-transparent collapsed hide-border-left'><div class='collapse-block-title'><span class='collapse-block-title-inner'>evaluate\u65b9\u6cd5<\/span><i class='collapse-icon fa fa-angle-down'><\/i><\/div><div class='collapse-block-body' style='display:none;'><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>const parse = require('@babel\/parser')\nconst {types} = require(\"@babel\/core\");\nconst traverse = require('@babel\/traverse').default\nconst generator = require(\"@babel\/generator\").default;\n\njscode = `function _xl(){\n x = 1 + 2 + 3 +4 + 5 + 6 + 7\n }`\nlet ast = parse.parse(jscode)\n\n\nconst vis = {\n    \"BinaryExpression|Identifier\"(path) {\n        const {confident, value} = path.evaluate();\n        confident &amp;&amp; path.replaceInline(types.valueToNode(value))\n    }\n}\n\ntraverse(ast, vis)\n\nconst {code} = generator(ast)\nconsole.log(code);\n<\/code><\/pre>\n\n\n\n<p><\/div><\/div>\n\n\n\n<div  class='collapse-block shadow-sm collapse-block-transparent collapsed hide-border-left'><div class='collapse-block-title'><span class='collapse-block-title-inner'>\u7f16\u7801\u7c7b\u578b\u8fd8\u539f<\/span><i class='collapse-icon fa fa-angle-down'><\/i><\/div><div class='collapse-block-body' style='display:none;'><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>const parse = require('@babel\/parser')\nconst {types} = require(\"@babel\/core\");\nconst traverse = require('@babel\/traverse').default\nconst generator = require(\"@babel\/generator\").default;\n\njscode = `var a = 0x25,b = 0b10001001,c = 0o123456,\n d = \"\\x68\\x65\\x6c\\x6c\\x6f\\x2c\\x41\\x53\\x54\",\n e = \"\\u0068\\u0065\\u006c\\u006c\\u006f\\u002c\\u0041\\u0053\\u0054\";`\nlet ast = parse.parse(jscode)\n\n\nconst vis = {\n    NumericLiteral({node}) {\n        if (node.extra &amp;&amp; \/^0&#091;obx]\/i.test(node.extra.raw)) {\n            node.extra = undefined;\n        }\n    },\n    StringLiteral({node}) {\n        if (node.extra &amp;&amp; \/\\\\&#091;ux]\/gi.test(node.extra.raw)) {\n            node.extra = undefined;\n        }\n    },\n}\n\ntraverse(ast, vis)\n\nconst {code} = generator(ast)\nconsole.log(code);\n<\/code><\/pre>\n\n\n\n<p><\/div><\/div>\n\n\n\n<div  class='collapse-block shadow-sm collapse-block-transparent collapsed hide-border-left'><div class='collapse-block-title'><span class='collapse-block-title-inner'>\u4e09\u5143\u8868\u8fbe\u5f0f\u8fd8\u539f<\/span><i class='collapse-icon fa fa-angle-down'><\/i><\/div><div class='collapse-block-body' style='display:none;'><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>const parse = require('@babel\/parser')\nconst {types} = require(\"@babel\/core\");\nconst traverse = require('@babel\/traverse').default\nconst generator = require(\"@babel\/generator\").default;\n\njscode = `var d =true?1:2;`\nlet ast = parse.parse(jscode)\n\n\nconst vis = {\n    \"BinaryExpression|UnaryExpression|ConditionalExpression\"(path) {\n\/\/ \u9632\u6b62\u6ea2\u51fa\n        if (path.isUnaryExpression({operator: \"-\"}) ||\n            path.isUnaryExpression({operator: \"void\"})) {\n            return;\n        }\n        const {confident, value} = path.evaluate();\n        if (!confident)\n            return;\n        if (typeof value == 'number' &amp;&amp; (!Number.isFinite(value))) {\n            return;\n        }\n        path.replaceWith(types.valueToNode(value));\n    },\n}\n\ntraverse(ast, vis)\n\nconst {code} = generator(ast)\nconsole.log(code);\n<\/code><\/pre>\n\n\n\n<p><\/div><\/div>\n\n\n\n<h4 class=\"wp-block-heading\">2.3 generator\u4f7f\u7528<\/h4>\n\n\n\n<p>\u751f\u6210\u8fd8\u539f\u540e\u7684js\u4ee3\u7801<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>\/\/ \u5220\u9664\u6240\u6709\u6ce8\u91ca\uff0c\u5176\u4ed6\u9009\u9879\u53ef\u5230\u5b98\u7f51\u67e5\u8be2\nconst {code} = generator(ast,opts = {\"comments\":false});<\/code><\/pre>\n\n\n\n<div  class='collapse-block shadow-sm collapse-block-transparent collapsed hide-border-left'><div class='collapse-block-title'><span class='collapse-block-title-inner'>\u4f5c\u4e1a<\/span><i class='collapse-icon fa fa-angle-down'><\/i><\/div><div class='collapse-block-body' style='display:none;'><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>const parse = require('@babel\/parser')\nconst {types} = require(\"@babel\/core\");\nconst traverse = require('@babel\/traverse').default\nconst generator = require(\"@babel\/generator\").default;\n\njscode = `\nconst a = !!&#091;]+!!&#091;]+!!&#091;];\nconst b = Math.floor(12.34 * 2.12)\nconst c = 10 >> 3 &lt;&lt; 1\nconst d = String(21.3 + 14 * 1.32)\nconst e = parseInt(\"1.893\" + \"45.9088\")\nconst f = parseFloat(\"23.2334\" + \"21.89112\")\nconst g = 20 &lt; 18 ? '1' : '2'\n`\nlet ast = parse.parse(jscode)\n\nconst vis1 = {\n    \"BinaryExpression|Identifier\"(path) {\n        const {confident, value} = path.evaluate();\n        confident &amp;&amp; path.replaceInline(types.valueToNode(value))\n    }\n}\ntraverse(ast, vis1)\n\nconst vis2 = {\n    CallExpression(path) {\n        let {callee, arguments} = path.node\n        if (path.get('callee').isMemberExpression() &amp;&amp; callee.object.name == 'Math' &amp;&amp; callee.property.name == 'floor') {\n            path.replaceWith(types.valueToNode(Math.floor(arguments&#091;0].value)))\n        } else if (path.get('callee').isIdentifier() &amp;&amp; callee.name == 'String') {\n            path.replaceWith(types.valueToNode(String(arguments&#091;0].value)))\n        } else if (path.get('callee').isIdentifier() &amp;&amp; callee.name == 'parseInt') {\n            path.replaceWith(types.valueToNode(parseInt(arguments&#091;0].value)))\n        } else if (path.get('callee').isIdentifier() &amp;&amp; callee.name == 'parseFloat') {\n            path.replaceWith(types.valueToNode(parseFloat(arguments&#091;0].value)))\n        } else {\n\n        }\n    },\n    \"BinaryExpression|UnaryExpression|ConditionalExpression\"(path) {\n        if (path.isUnaryExpression({operator: \"-\"}) ||\n            path.isUnaryExpression({operator: \"void\"})) {\n            return;\n        }\n        const {confident, value} = path.evaluate();\n        if (!confident)\n            return;\n        if (typeof value == 'number' &amp;&amp; (!Number.isFinite(value))) {\n            return;\n        }\n        path.replaceWith(types.valueToNode(value));\n    },\n}\ntraverse(ast, vis2)\n\nconst {code} = generator(ast, opt = {compact: false})\nconsole.log(code);\n<\/code><\/pre>\n\n\n\n<p><\/div><\/div>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>AST\u7b80\u4ecb\uff1a\u539f\u7406\u89e3\u6790\uff1aJS \u4ee3\u7801\u662f\u5982\u4f55\u88ab\u6d4f\u89c8\u5668\u5f15\u64ce\u7f16\u8bd1\u3001\u6267\u884c\u7684\uff1f_js \u7f16\u8bd1\u89e3\u6790?.-CSDN\u535a\u5ba2 AST\u5728\u7ebf [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-1183","post","type-post","status-publish","format-standard","hentry","category-js"],"_links":{"self":[{"href":"https:\/\/www.xiaosuigu.top\/index.php\/wp-json\/wp\/v2\/posts\/1183","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.xiaosuigu.top\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.xiaosuigu.top\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.xiaosuigu.top\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.xiaosuigu.top\/index.php\/wp-json\/wp\/v2\/comments?post=1183"}],"version-history":[{"count":0,"href":"https:\/\/www.xiaosuigu.top\/index.php\/wp-json\/wp\/v2\/posts\/1183\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.xiaosuigu.top\/index.php\/wp-json\/wp\/v2\/media?parent=1183"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.xiaosuigu.top\/index.php\/wp-json\/wp\/v2\/categories?post=1183"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.xiaosuigu.top\/index.php\/wp-json\/wp\/v2\/tags?post=1183"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}