awk macro: more Awk-like treatment of prn args.

* share/txr/stdlib/awk.tl (sys:awk-state prn):
Use loop instead of simple interpolation, so that
we we can individually interpolate each arg into a
quasistring. This way if an arg is nil, it turns
into nothing rather than the word "nil".

* txr.1: Documented this behavior of prn.

1 files changed, 14 insertions, 0 deletions

diff --git a/txr.1 b/txr.1
index 2d8e181d..02f62750 100644
--- a/txr.1
+++ b/txr.1
@@ -37778,6 +37778,20 @@ then a call to
 .code prn
 with no arguments is the default action.
 
+Each argument
+.meta form
+is printed by conversion to a string, as if by the expression
+.code `@val`
+where
+.code val
+is some variable which holds the value produced by the
+evaluation of
+.metn form .
+Thus if the value is
+.codn nil ,
+the output for that argument is an empty string, rather than the text
+.strn nil .
+
 .coNP Macro @ next
 .synb
 .mets (next)