> Notice how the decoded values give relative positions, each value represents the difference from the previous position, not absolute coordinates. This is crucial: instead of encoding large column numbers like 27698 in minified files, source maps only store small deltas like +7 or +15, making the encoded strings much more compact.
To me, “offset” sounds more like the distance from the start, whereas here the values are relative to the previous segment.
Not a native english speaker, so I could be wrong.
I feel like choosing the synonym that happens to be one letter shorter when the operation is literally intended to track things in a way that's more conscise is about as "apt" as it could be!
Tangentially related, but last year I've made a tool to recover original sources from web apps which expose source maps (with the sourcesContent value present), including enumerating all lazily loaded chunks:
Recent related post where Apple seemingly forgot to disable source maps for the App Store
Apple's App Store Full Front End Source Code
https://news.ycombinator.com/item?id=45804664
edit: formatting
I love it when things are displayed so nicely on mobile. This could've been a pain to read and get through but it was actually quite pleasant.
> Notice how the decoded values give relative positions, each value represents the difference from the previous position, not absolute coordinates. This is crucial: instead of encoding large column numbers like 27698 in minified files, source maps only store small deltas like +7 or +15, making the encoded strings much more compact.
Wouldn't "offset" be a more apt term?
To me, “offset” sounds more like the distance from the start, whereas here the values are relative to the previous segment. Not a native english speaker, so I could be wrong.
Offset is difference from a starting point or a previous position
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Delta Encoding is the common term
Agreed... Delta Encoding, or even Delta Offset would work together.
In this case I feel it's like six of one and a half-dozen of the other.
Delta definition 4: (mathematics, physics, engineering) The symbol Δ; A change in a quantity, likely from "d" for "difference"
Offset definition 7: The distance by which one thing is out of alignment with another.
Got these from Wiktionary:
* https://en.wiktionary.org/wiki/delta
* https://en.wiktionary.org/wiki/offset
It sounds equally apt to my ear. I've used both words for this concept in the past.
Delta and offset mean the same thing — the difference between two amounts.
Delta is perhaps slightly more obscure outside of a math setting. Perhaps.
I feel like choosing the synonym that happens to be one letter shorter when the operation is literally intended to track things in a way that's more conscise is about as "apt" as it could be!
Tangentially related, but last year I've made a tool to recover original sources from web apps which expose source maps (with the sourcesContent value present), including enumerating all lazily loaded chunks:
https://github.com/zb3/getfrontend