It'd be good to add a library of various functions to help with processing CSV files (or other tabular data, it wouldn't be limited to CSV). For example:

• The printrow() function mentioned in csv.md.
• If we add the above, may also want a printheader() function that prints the names in OFIELDS (or just use print?).
• A function to delete a field or fields, for example delfield(n) to delete a single field, or maybe delfield(n[, c]) to delete c fields starting at field n (c defaults to 1). For one implementation, see the rmcol definition in this StackOverflow answer.
  • Do we also need a delfieldbyname()? Though with a better name.
• A function to insert a field or fields, eg insfield(n, val). With standard AWK you can kind of cheat with something like {$n=val FS $n;}, but that doesn't work for CSV escaping.

We could start by making this a simple AWK library that you include, eg goawk -f lib.awk -f prog.awk (prepend/append the library to the source when using the Go API).

When we want to add them as builtins to GoAWK, we should do it in a backwards-compatible way (i.e., not make them keywords like the other builtins, but if the user redefines a function or variable with that same name, that takes precedence).