I would guess the most useful part of that is that would allow parsing to proceed further.
I used an Algol compiler that had messages such as:
Semicolon missing after end (inserted)
Undeclared identifier ‘foo’ (assumed integer)
Both of these hugely improved the compiler output, as far fewer utterly useless error messages would be produced (yes, I know I didn’t declare ‘foo’. You told me so the previous 12 times I used it)
Parsing valid programs is easy, so are bailing out or going into the woods when encountering invalid syntax. Producing meaningful error messages for line 100 after having seen errors on lines 13, 42 and 78 can be fairly hard.
Couple this with ast and source similarity search (how this is enabled is tbd) would allow one to not only suggest how to complete the program via the compiler's analysis, but then also find code that was similar to your program across all source say in crates.io or on github.
Great learning tool, but also the ability to copy-pasta from terabytes of code ... (scurries off to do some analysis).
I used an Algol compiler that had messages such as:
Both of these hugely improved the compiler output, as far fewer utterly useless error messages would be produced (yes, I know I didn’t declare ‘foo’. You told me so the previous 12 times I used it)Parsing valid programs is easy, so are bailing out or going into the woods when encountering invalid syntax. Producing meaningful error messages for line 100 after having seen errors on lines 13, 42 and 78 can be fairly hard.