> 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?
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:
Delta Encoding is the common 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
“Offset” is not enough on its own. Offset from what? Start of file? Absolute offset. Previous offset? Relative offset.
2nd order offset. The offset from the <offset from the start of the file>
perhaps the delta between offsets
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.
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: