awk: add CSV support.

* stdlib/awk (awk-state upd-rec-to-f): Handle a new case
of fs being the keyword symbol :csv, producing a
field-splitting lambda that calls get-csv.

* tests/015/awk-basic.tl: Several new test cases for
this CSV feature.

* txr.1: Documented.

1 files changed, 8 insertions, 0 deletions

diff --git a/stdlib/awk.tl b/stdlib/awk.tl
index 50121736..35bd436e 100644
--- a/stdlib/awk.tl
+++ b/stdlib/awk.tl
@@ -95,6 +95,14 @@
                       (if (< end l)
                         (add [self.rec end..:])))
                     self.nf i))))
+         ((eq self.fs :csv)
+          (when self.ft
+             (awk-error "both fs and ft set"))
+          (when self.kfs
+             (awk-error "fs set to :csv and ft set"))
+          (lambda (self)
+            (set self.fields (get-csv self.rec)
+                 self.nf (length self.fields))))
          (self.fs
            (when self.ft
              (awk-error "both fs and ft set"))