From b4f23d86dd71504405f2f26278941dd8325c14ab Mon Sep 17 00:00:00 2001
From: Kaz Kylheku <kaz@kylheku.com>
Date: Wed, 24 May 2023 06:48:18 -0700
Subject: awk: widen scope of redirection macros.

This change makes it possible to use the redirection macros
like -> and ->> everywhere in the awk macro, including the
init-forms of the :let clause.

* stdlib/awk.tl (sys:awk-mac-let-outer): New macro.
(sys:awk-mac-let): Move redirection macros into
awk-mac-let-outer.
(awk): Rearrange the order of wrapping. We split the
let so the awk-retval and aws-sym are bound outermost.
Then we have the outer macros that provide the
redirection operators. Then the application-defined
lets inside of that.

* txr.1: Documented wide scope of redirection macros.
---
 stdlib/awk.tl | 83 +++++++++++++++++++++++++++++++----------------------------
 txr.1         |  8 ++++++
 2 files changed, 52 insertions(+), 39 deletions(-)

diff --git a/stdlib/awk.tl b/stdlib/awk.tl
index 1ce292ef..09065bf7 100644
--- a/stdlib/awk.tl
+++ b/stdlib/awk.tl
@@ -462,18 +462,21 @@
                   ^(symacrolet ((f (usr:rslot ,',aws-sym 'fields 'f-to-rec)))
                      (set f (mapcar (opip ,*opip-args) f))))
                 (fconv (. conv-args)
-                  ^(set f (sys:conv (,*conv-args) f)))
-                (-> (path . body)
+                  ^(set f (sys:conv (,*conv-args) f))))
+       ,*body)))
+
+(defmacro sys:awk-mac-let-outer (aws-sym . body)
+  ^(macrolet ((-> (path . body)
                   ^(sys:awk-redir ,',aws-sym *stdout* :outf "w" ,path ,body))
-                (->> (path . body)
-                  ^(sys:awk-redir ,',aws-sym *stdout* :apf "a" ,path ,body))
-                (<- (path . body)
+              (->> (path . body)
+                   ^(sys:awk-redir ,',aws-sym *stdout* :apf "a" ,path ,body))
+              (<- (path . body)
                   ^(sys:awk-redir ,',aws-sym *stdin* :inf "r" ,path ,body))
-                (!> (path . body)
+              (!> (path . body)
                   ^(sys:awk-redir ,',aws-sym *stdout* :outp "w" ,path ,body))
-                (<! (path . body)
+              (<! (path . body)
                   ^(sys:awk-redir ,',aws-sym *stdin* :inp "r" ,path ,body)))
-       ,*body)))
+     ,*body))
 
 (defmacro sys:awk-fun-let (aws-sym . body)
   ^(flet ((prn (. args)
@@ -539,35 +542,37 @@
                   ,(sys:awk-field-name-code awc aws-sym)
                   ,p-actions-xform)))
         ^(block ,(or awc.name 'awk)
-           (let* (,*awc.lets ,awk-retval
-                  (,aws-sym (new sys:awk-state
-                                 ,*(if awc.inputs ^(inputs (list ,*awc.inputs)))
-                                 ,*(if awc.output ^(output ,awc.output))
-                                 rng-n (macro-time (qref ,awc nranges)))))
-             (sys:awk-mac-let ,awc ,aws-sym
-               (sys:awk-fun-let ,aws-sym
-                 (sys:awk-symac-let ,awc
-                   (let* (,*(if awc.output
-                              ^((*stdout* (qref ,aws-sym output))))
-                          ,*(if (and awc.cond-actions awc.begin-file-actions)
-                              ^((,awk-begf-fun (lambda (,aws-sym)
-                                   ,*awc.begin-file-actions))))
-                          ,*(if (and awc.cond-actions awc.end-file-actions)
-                              ^((,awk-endf-fun (lambda (,aws-sym)
-                                  ,*awc.end-file-actions))))
-                          ,*(if (or awc.cond-actions awc.begin-file-actions
+           (let (,awk-retval
+                 (,aws-sym (new sys:awk-state
+                                ,*(if awc.inputs ^(inputs (list ,*awc.inputs)))
+                                ,*(if awc.output ^(output ,awc.output))
+                                rng-n (macro-time (qref ,awc nranges)))))
+             (sys:awk-mac-let-outer ,aws-sym
+               (let* ,awc.lets
+                 (sys:awk-mac-let ,awc ,aws-sym
+                   (sys:awk-fun-let ,aws-sym
+                     (sys:awk-symac-let ,awc
+                       (let* (,*(if awc.output
+                                  ^((*stdout* (qref ,aws-sym output))))
+                               ,*(if (and awc.cond-actions awc.begin-file-actions)
+                                   ^((,awk-begf-fun (lambda (,aws-sym)
+                                                      ,*awc.begin-file-actions))))
+                               ,*(if (and awc.cond-actions awc.end-file-actions)
+                                   ^((,awk-endf-fun (lambda (,aws-sym)
+                                                      ,*awc.end-file-actions))))
+                               ,*(if (or awc.cond-actions awc.begin-file-actions
+                                         awc.end-file-actions awc.end-actions)
+                                   ^((,awk-fun (lambda (,aws-sym)
+                                                 ,p-actions-xform)))))
+                         ,*awc.begin-actions
+                         (unwind-protect
+                           ,(if (or awc.cond-actions awc.begin-file-actions
                                     awc.end-file-actions awc.end-actions)
-                              ^((,awk-fun (lambda (,aws-sym)
-                                            ,p-actions-xform)))))
-                     ,*awc.begin-actions
-                       (unwind-protect
-                         ,(if (or awc.cond-actions awc.begin-file-actions
-                                  awc.end-file-actions awc.end-actions)
-                            ^(qref ,aws-sym (loop ,awk-fun
-                                              ,(if awc.begin-file-actions
-                                                 awk-begf-fun)
-                                              ,(if awc.end-file-actions
-                                                 awk-endf-fun))))
-                         (set ,awk-retval (progn ,*awc.end-actions))
-                         (call-finalizers ,aws-sym))
-                       ,awk-retval))))))))))
+                              ^(qref ,aws-sym (loop ,awk-fun
+                                                    ,(if awc.begin-file-actions
+                                                       awk-begf-fun)
+                                                    ,(if awc.end-file-actions
+                                                       awk-endf-fun))))
+                           (set ,awk-retval (progn ,*awc.end-actions))
+                           (call-finalizers ,aws-sym))
+                         ,awk-retval))))))))))))
diff --git a/txr.1 b/txr.1
index b18b529f..f1d5d6ea 100644
--- a/txr.1
+++ b/txr.1
@@ -69716,6 +69716,14 @@ or
 string, direction and type, a new stream is not opened; rather, the
 previously associated stream is used.
 
+The scope of these macros is the entire containing
+.code awk
+form; they may be used in the
+.metn init-form s
+of the
+.code :let
+clause.
+
 The
 .code ->
 macro indicates that the file named
-- 
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