What should semantic diffs highlight: The change or its effect?
What should semantic diffs highlight: The change or its effect?
Language aware diffs can detect changes in the semantics of the code that are invisible to traditional diffs. How should they be highlighted?
this is neat but also is a closed source extension. I use https://github.com/Wilfred/difftastic which doesn't do quite as much and doesn't integrate outside of git's diff, but is still significantly better than nothing
I like the way azure dev-ops do it, they highlight the entire line with a soft color and the changes with a harder one. Isn't not semantic afaik.
The most obvious option: highlight what changed, the whole string. If you changed the string from interpolated to non-interpolated, the meaning of the whole string changed; it is no longer a method to concatenate variables, it has become a literal string.
Same for the example of single to double quotes. In some languages, double quotes are only used in specific contexts, so its use changes the meaning of the code. The post seems to dismiss this fact too easily.
The post chooses to use Python, where single and double quotes are equivalent and are not a semantic change. In other languages that might be, but that's not the point of the article. A semantic diff is language dependent.
Just because they are equivalent for the labguage does not mean they are interchangeable. I may choose to use single or double quotes in specific cases and need that change to be visible, even if the language rules say it is indifferent.
This is the obvious one: The way the string is written changes, but its content remains the same. There is nothing to highlight for SemanticDiff.
Moreover, my point was about how they phrase it. It seems they dismiss what the code means to developer by mentioning "content" and discarding "the way the string is written".
I don't see what's the point of the second one if the syntax highlight, even in the first example, already shows a changed role.
A more realistic solution for the example code would be to setup a linter in the pipeline, and if one letter variables and/or template literals are detected, depending on how nice you are, reject the commit, or send an email requesting the author to be beaten up with a crowbar to the teamlead, and a copy, parsed by chatGPT for formality and politeness, to the HR.
that's not a one letter template literal, that's built in python syntax. it only has combinations of u r and f and no user defined option. f makes it templated
I don't speak python. Does the f in the top example affect string interpolation or something? If the above replaces {bar} and the below does not, highlight all after the equals sign would be my preference.
it allows string interpolation with the syntax in the photo
Options 1 and 3 make sense to me.
Option 2 feels like something specific:
Similar to cases like100vs100Uwith the second one denoting "unsigned".""to''… There is nothing to highlight for SemanticDiff.Really? I definitely want to see that. I want to be deliberate about my code. I am not only targeting compiled code. I am also targeting developers through maintainable code.
I'm surprised they did not list an alternative that would be my preference: Highlight the entire string. The
fprefix changes the entire text value type. I would like the `f´ to be highlighted strongly, and string it changes the interpretation of weakly, and the placeholder variable more strongly again.Many code formatters decide whether to use
"or'based on some configuration and whether the default one would require escaping. So if you are using such a code formatter, this is no longer a deliberate choice unless you explicitly override the behavior with annotations.I am not sure whether your solution of using a less intense color for the unchanged part of the string would make it clearer. It is just more similar to other diff tools that highlight the whole line with a less intense color if it contains changes.
would make it clearer
Would make what clearer?
If I change a string to a raw string or an interpolated string, it is a semantic change on the entire string, even if it leads to consequential changes only on subsections of it. The next time or additional changes I make must take different semantics into account.
If the formatting configuration forces one specific style then that is the deliberate choice; to have that one.
If there is no uniform single string quoting it is useful to differentiate between them; for example if for normal strings
'is preferred while for specific cases where escaping characters like\nis required,"must be used.
This is an interesting problem to mull over; thanks for posting it!