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							96 lines
						
					
					
						
							2.4 KiB
						
					
					
				
			
		
		
	
	
							96 lines
						
					
					
						
							2.4 KiB
						
					
					
				import { createPath } from "./node-path"; | 
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import { unionTypesMap, nodeAndUnionTypes } from "./nodes"; // recursively walks the AST starting at the given node. The callback is invoked for | 
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// and object that has a 'type' property. | 
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 | 
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function walk(context, callback) { | 
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  var stop = false; | 
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 | 
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  function innerWalk(context, callback) { | 
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    if (stop) { | 
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      return; | 
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    } | 
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 | 
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    var node = context.node; | 
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 | 
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    if (node === undefined) { | 
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      console.warn("traversing with an empty context"); | 
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      return; | 
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    } | 
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 | 
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    if (node._deleted === true) { | 
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      return; | 
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    } | 
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 | 
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    var path = createPath(context); | 
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    callback(node.type, path); | 
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 | 
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    if (path.shouldStop) { | 
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      stop = true; | 
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      return; | 
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    } | 
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 | 
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    Object.keys(node).forEach(function (prop) { | 
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      var value = node[prop]; | 
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 | 
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      if (value === null || value === undefined) { | 
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        return; | 
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      } | 
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 | 
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      var valueAsArray = Array.isArray(value) ? value : [value]; | 
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      valueAsArray.forEach(function (childNode) { | 
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        if (typeof childNode.type === "string") { | 
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          var childContext = { | 
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            node: childNode, | 
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            parentKey: prop, | 
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            parentPath: path, | 
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            shouldStop: false, | 
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            inList: Array.isArray(value) | 
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          }; | 
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          innerWalk(childContext, callback); | 
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        } | 
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      }); | 
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    }); | 
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  } | 
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 | 
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  innerWalk(context, callback); | 
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} | 
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 | 
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var noop = function noop() {}; | 
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 | 
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export function traverse(node, visitors) { | 
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  var before = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : noop; | 
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  var after = arguments.length > 3 && arguments[3] !== undefined ? arguments[3] : noop; | 
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  Object.keys(visitors).forEach(function (visitor) { | 
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    if (!nodeAndUnionTypes.includes(visitor)) { | 
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      throw new Error("Unexpected visitor ".concat(visitor)); | 
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    } | 
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  }); | 
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  var context = { | 
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    node: node, | 
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    inList: false, | 
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    shouldStop: false, | 
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    parentPath: null, | 
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    parentKey: null | 
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  }; | 
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  walk(context, function (type, path) { | 
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    if (typeof visitors[type] === "function") { | 
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      before(type, path); | 
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      visitors[type](path); | 
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      after(type, path); | 
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    } | 
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 | 
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    var unionTypes = unionTypesMap[type]; | 
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 | 
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    if (!unionTypes) { | 
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      throw new Error("Unexpected node type ".concat(type)); | 
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    } | 
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 | 
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    unionTypes.forEach(function (unionType) { | 
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      if (typeof visitors[unionType] === "function") { | 
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        before(unionType, path); | 
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        visitors[unionType](path); | 
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        after(unionType, path); | 
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      } | 
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    }); | 
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  }); | 
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} |