feat: add support for getLocFromIndex and getIndexFromLoc
#212
Conversation
…c' of https://github.com/eslint/rewrite into feat-add-support-for-getlocfromindex-and-getindexfromloc
There was a problem hiding this comment.
It took a while, but I’ve finally finished implementing these two methods 😄
I’ve carefully reviewed the lazy calculation and addressed all the comments.
There might still be room for improvement—if so, I’d be happy to take a look.
(I didn’t go with the caching approach, as it turned out to be slightly slower in eslint/eslint#19782)
| * @param {number} targetIndex The target index to find the line number for. | ||
| * @returns {number} The line number for the target index. | ||
| */ | ||
| function findLineNumberBinarySearch(lineStartIndices, targetIndex) { |
There was a problem hiding this comment.
I’ve applied the binary‑search logic suggested in eslint/eslint#19782.
| * Ensures `#lines` is lazily calculated from the source text. | ||
| * @returns {void} | ||
| */ | ||
| #ensureLines() { |
There was a problem hiding this comment.
I’ve also applied lazy calculation to the lines getter method.
When I looked into the rules of the JavaScript, JSON, CSS, Markdown, HTML plugins (yeonjuan/html-eslint), and my custom plugins, I found that the lines getter is rarely used.
So, if we make the lines getter lazy, it would reduce unnecessary computation and memory usage.
| ); | ||
| } | ||
|
|
||
| const rootNodeLoc = this.getLoc(this.ast); |
There was a problem hiding this comment.
Now, we retrieve lineStart and columnStart information from the AST.
Prerequisites checklist
What is the purpose of this pull request?
Hello,
In this PR, I've completed implemention of
getLocFromIndex()andgetIndexFromLoc().I based the implementation on the current JavaScript
SourceCodeclass and incorporated the fast lookup algorithm discussed in eslint/eslint#19782.The logic of
getLocFromIndex()andgetIndexFromLoc()is nearly identical to that in the JavaScriptSourceCodeclass, with the key difference being that it accounts for thelineStartandcolumnStartvalues initialized in the constructor.lineStartandcolumnStartTextSourceCodeBaseshould acceptlineStartandcolumnStart, as these can vary depending on the language, and bothgetLocFromIndex()andgetIndexFromLoc()rely on them for accurate calculations. Here are some examples:What changes did you make? (Give an overview)
I've completed implemention of
getLocFromIndex()andgetIndexFromLoc().Related Issues
fixes: #166
refs: eslint/markdown#376, eslint/css#167, eslint/json#109, eslint/eslint#19782
Is there anything you'd like reviewers to focus on?
Prerequisites
getLocFromIndexeslint#19782