Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

disableInputAttributeSyncing #2

Closed
wants to merge 2 commits into from
Closed

disableInputAttributeSyncing #2

wants to merge 2 commits into from

Conversation

kassens
Copy link
Owner

@kassens kassens commented Nov 18, 2022

@kassens kassens closed this Nov 19, 2022
@kassens kassens deleted the disableInputAttributeSyncing branch March 19, 2024 19:02
kassens pushed a commit that referenced this pull request Jun 4, 2024
@mofeiZ
[babel][contextvar] Patch context identifier babel logic; only use re…
241a615 
…ferenced

identifiers 

--- 

A few fixes for finding context identifiers: 

Previously, we counted every babel identifier as a reference. This is 
problematic because babel counts every string symbol as an identifier. 

```js 

print(x);  // x is an identifier as expected 

obj.x      // x is.. also an identifier here 

{x: 2}     // x is also an identifier here 

``` 

This PR adds a check for `isReferencedIdentifier`. Note that only non-lval 
references pass this check 

```js 

print(x);  // isReferencedIdentifier(x) -> true 

obj.x      // isReferencedIdentifier(x) -> false 

{x: 2}     // isReferencedIdentifier(x) -> false 

x = 2      // isReferencedIdentifier(x) -> false 

``` 

Which brings us to change #2. 

Previously, we counted assignments as references due to the identifier visiting 
+ checking logic. The logic was roughly the following (from facebook#1691) 

```js 

contextVars = intersection(reassigned, referencedByInnerFn); 

``` 

Now that assignments (lvals) and references (rvals) are tracked separately, the 
equivalent logic is this. Note that assignment to a context variable does not 
need to be modeled as a read (`console.log(x = 5)` always will evaluates and 
prints 5, regardless of the previous value of x). 

``` 

contextVars = union(reassignedByInnerFn, intersection(reassigned, 
referencedByInnerFn)) 

``` 

--- 

Note that variables that are never read do not need to be modeled as context 
variables, but this is unlikely to be a common pattern. 

```js 

function fn() { 

let x = 2; 

const inner = () => { 

x = 3; 

} 

} 

```
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Reviewers
No reviews
Assignees
No one assigned
Labels
None yet
Projects
None yet
Milestone
No milestone
Development

Successfully merging this pull request may close these issues.
2 participants
@kassens @colinhacks