awk: :fields specifies conversions.

* stdlib/awk.tl (sys:awk-compile-time): Slot field-names renamed to
field-name-conv.
(sys:awk-expander): Parse the new syntax which allows (sym fn)
pairs with optional fn, creating a list of normalized items
in the field-name-conv slot of the compile-time structure.
(sys:awk-symac-let): Adjust the code to the pair representation in
field-name-conv.
(sys:awk-field-name-code): New function for generating the
field conversion code.
(awk): Now that we have two optional pieces of code to wrap around
p-actions form, we factor that out of the awk-lambda, to a series
of conditional assignments. Here we handle the generation of the
field conversionns.

* conv.tl (sys:conv-expand-sym): New macro, used in
sys:awk-field-name-code and sys:conv-let.
(sys:conv-let): Simplify with sys:conv-expand-sym. Drop optional
argument from i; it connects with no documented feature, and is
not usable from fconv.

* tests/015/awk-fields.tl: New tests.

* txr.1: Updated, including cruft in fconv documentation.

Change-Id: Ie42819f58af039fdbcdb1ae365c89dc1add55c93

1 files changed, 20 insertions, 1 deletions

diff --git a/tests/015/awk-fields.tl b/tests/015/awk-fields.tl
index 7f27e9e4..7bb2f599 100644
--- a/tests/015/awk-fields.tl
+++ b/tests/015/awk-fields.tl
@@ -6,7 +6,10 @@
   (awk (:fields nil) (:begin (return-from awk))) :error
   (awk (:fields - -) (:begin (return-from awk))) nil
   (awk (:fields a - - b) (:begin (return-from awk))) nil
-  (awk (:fields a - - a) (:begin (return-from awk))) :error
+  (awk (:fields (a foo) - - (a bar)) (:begin (return-from awk))) :error
+  (awk (:fields (a foo) - - (b bar)) (:begin (return-from awk))) nil
+  (awk (:fields (a foo) (-) - (b bar)) (:begin (return-from awk))) :error
+  (awk (:fields (a foo) (- i) - (b bar)) (:begin (return-from awk))) :error
   (awk (:fields a) (:fields b) (:begin (return-from awk))) :error)
 
 (test
@@ -16,3 +19,19 @@
       (:fields h n - c)
       (t (add h n c))))
   ("How" "now" "cow"))
+
+(test
+  (build
+    (awk
+      (:inputs '("1 x 2" "a x 1" "4 x b"))
+      (:fields (foo iz) - (bar iz))
+      (t (add (+ foo bar)))))
+  (3 1 4))
+
+(test
+  (build
+    (awk
+      (:inputs '("1"))
+      (:fields (a iz) - (c iz))
+      (t (add (+ a c) nf))))
+  (1 3))