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										 |  |  | /** | 
					
						
							|  |  |  |  * @license | 
					
						
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										 |  |  |  * Copyright Google LLC All Rights Reserved. | 
					
						
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											2019-07-29 13:23:29 -07:00
										 |  |  |  * | 
					
						
							|  |  |  |  * Use of this source code is governed by an MIT-style license that can be | 
					
						
							|  |  |  |  * found in the LICENSE file at https://angular.io/license
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							|  |  |  |  */ | 
					
						
							|  |  |  | 
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							|  |  |  | import {AbsoluteSourceSpan} from '@angular/compiler'; | 
					
						
							|  |  |  | import * as e from '../../../src/expression_parser/ast'; | 
					
						
							|  |  |  | import * as t from '../../../src/render3/r3_ast'; | 
					
						
							|  |  |  | import {unparse} from '../../expression_parser/utils/unparser'; | 
					
						
							|  |  |  | 
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							|  |  |  | type HumanizedExpressionSource = [string, AbsoluteSourceSpan]; | 
					
						
							|  |  |  | class ExpressionSourceHumanizer extends e.RecursiveAstVisitor implements t.Visitor { | 
					
						
							|  |  |  |   result: HumanizedExpressionSource[] = []; | 
					
						
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										 |  |  |   private recordAst(ast: e.AST) { | 
					
						
							|  |  |  |     this.result.push([unparse(ast), ast.sourceSpan]); | 
					
						
							|  |  |  |   } | 
					
						
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												refactor(compiler): Remove NullAstVisitor and visitAstChildren (#35619)
This commit removes the `NullAstVisitor` and `visitAstChildren` exported
from `packages/compiler/src/expression_parser/ast.ts` because they
contain duplicate and buggy implementation, and their use cases could be
sufficiently covered by `RecursiveAstVisitor` if the latter implements the
`visit` method. This use case is only needed in the language service.
With this change, any visitor that extends `RecursiveAstVisitor` could
just define their own `visit` function and the parent class will behave
correctly.
A bit of historical context:
In language service, we need a way to tranverse the expression AST in a
selective manner based on where the user's cursor is. This means we need a
"filtering" function to decide which node to visit and which node to not
visit. Instead of refactoring `RecursiveAstVisitor` to support this,
`visitAstChildren` was created. `visitAstChildren` duplicates the
implementation of `RecursiveAstVisitor`, but introduced some bugs along
the way. For example, in `visitKeyedWrite`, it visits
```
obj -> key -> obj
```
instead of
```
obj -> key -> value
```
Moreover, because of the following line
```
visitor.visit && visitor.visit(ast, context) || ast.visit(visitor, context);
```
`visitAstChildren` visits every node *twice*.
PR Close #35619
											
										 
											2020-02-21 10:20:52 -08:00
										 |  |  |   // This method is defined to reconcile the type of ExpressionSourceHumanizer
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							|  |  |  |   // since both RecursiveAstVisitor and Visitor define the visit() method in
 | 
					
						
							|  |  |  |   // their interfaces.
 | 
					
						
							|  |  |  |   visit(node: e.AST|t.Node, context?: any) { | 
					
						
							|  |  |  |     if (node instanceof e.AST) { | 
					
						
							|  |  |  |       node.visit(this, context); | 
					
						
							|  |  |  |     } else { | 
					
						
							|  |  |  |       node.visit(this); | 
					
						
							|  |  |  |     } | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  | 
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										 |  |  |   visitASTWithSource(ast: e.ASTWithSource) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     this.visitAll([ast.ast], null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitBinary(ast: e.Binary) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitBinary(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitChain(ast: e.Chain) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitChain(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitConditional(ast: e.Conditional) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitConditional(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitFunctionCall(ast: e.FunctionCall) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitFunctionCall(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitImplicitReceiver(ast: e.ImplicitReceiver) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitImplicitReceiver(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitInterpolation(ast: e.Interpolation) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitInterpolation(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitKeyedRead(ast: e.KeyedRead) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitKeyedRead(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitKeyedWrite(ast: e.KeyedWrite) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitKeyedWrite(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitLiteralPrimitive(ast: e.LiteralPrimitive) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitLiteralPrimitive(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitLiteralArray(ast: e.LiteralArray) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitLiteralArray(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitLiteralMap(ast: e.LiteralMap) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitLiteralMap(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitMethodCall(ast: e.MethodCall) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitMethodCall(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitNonNullAssert(ast: e.NonNullAssert) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitNonNullAssert(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitPipe(ast: e.BindingPipe) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitPipe(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitPrefixNot(ast: e.PrefixNot) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitPrefixNot(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitPropertyRead(ast: e.PropertyRead) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitPropertyRead(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitPropertyWrite(ast: e.PropertyWrite) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitPropertyWrite(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitSafeMethodCall(ast: e.SafeMethodCall) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitSafeMethodCall(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitSafePropertyRead(ast: e.SafePropertyRead) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitSafePropertyRead(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitQuote(ast: e.Quote) { | 
					
						
							|  |  |  |     this.recordAst(ast); | 
					
						
							|  |  |  |     super.visitQuote(ast, null); | 
					
						
							|  |  |  |   } | 
					
						
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										 |  |  |   visitTemplate(ast: t.Template) { | 
					
						
							|  |  |  |     t.visitAll(this, ast.children); | 
					
						
							|  |  |  |     t.visitAll(this, ast.templateAttrs); | 
					
						
							|  |  |  |   } | 
					
						
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										 |  |  |   visitElement(ast: t.Element) { | 
					
						
							|  |  |  |     t.visitAll(this, ast.children); | 
					
						
							|  |  |  |     t.visitAll(this, ast.inputs); | 
					
						
							|  |  |  |     t.visitAll(this, ast.outputs); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitReference(ast: t.Reference) {} | 
					
						
							|  |  |  |   visitVariable(ast: t.Variable) {} | 
					
						
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										 |  |  |   visitEvent(ast: t.BoundEvent) { | 
					
						
							|  |  |  |     ast.handler.visit(this); | 
					
						
							|  |  |  |   } | 
					
						
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										 |  |  |   visitTextAttribute(ast: t.TextAttribute) {} | 
					
						
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										 |  |  |   visitBoundAttribute(ast: t.BoundAttribute) { | 
					
						
							|  |  |  |     ast.value.visit(this); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitBoundEvent(ast: t.BoundEvent) { | 
					
						
							|  |  |  |     ast.handler.visit(this); | 
					
						
							|  |  |  |   } | 
					
						
							|  |  |  |   visitBoundText(ast: t.BoundText) { | 
					
						
							|  |  |  |     ast.value.visit(this); | 
					
						
							|  |  |  |   } | 
					
						
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										 |  |  |   visitContent(ast: t.Content) {} | 
					
						
							|  |  |  |   visitText(ast: t.Text) {} | 
					
						
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										 |  |  |   visitIcu(ast: t.Icu) { | 
					
						
							|  |  |  |     for (const key of Object.keys(ast.vars)) { | 
					
						
							|  |  |  |       ast.vars[key].visit(this); | 
					
						
							|  |  |  |     } | 
					
						
							|  |  |  |     for (const key of Object.keys(ast.placeholders)) { | 
					
						
							|  |  |  |       ast.placeholders[key].visit(this); | 
					
						
							|  |  |  |     } | 
					
						
							|  |  |  |   } | 
					
						
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										 |  |  | } | 
					
						
							|  |  |  | 
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							|  |  |  | /** | 
					
						
							|  |  |  |  * Humanizes expression AST source spans in a template by returning an array of tuples | 
					
						
							|  |  |  |  *   [unparsed AST, AST source span] | 
					
						
							|  |  |  |  * for each expression in the template. | 
					
						
							|  |  |  |  * @param templateAsts template AST to humanize | 
					
						
							|  |  |  |  */ | 
					
						
							|  |  |  | export function humanizeExpressionSource(templateAsts: t.Node[]): HumanizedExpressionSource[] { | 
					
						
							|  |  |  |   const humanizer = new ExpressionSourceHumanizer(); | 
					
						
							|  |  |  |   t.visitAll(humanizer, templateAsts); | 
					
						
							|  |  |  |   return humanizer.result; | 
					
						
							|  |  |  | } |