Awk macro prn becomes function.

* share/txr/stdlib/awk.tl (sys:awk-let): Renamed to
sys:awk-mac-let. Macrolet prn removed from here.
(sys:awk-fun-let): New macro, provides awk functions.
The prn function removed from sys:awk-mac-let is generated
here.
(sys:awk-fun-shadowing-env): New function.
(awk): Follow rename of sys:awk-let. When expanding p-action
forms, use only sys:awk-mac-let; do not include the awk
functions, which do not "vaporize" unlike local macros. To
compensate for not including the functions, extend the macro
environment with one that shadows the functions, so that
during this expansion, any global macros of the same name as
awk local functions are properlly hidden.  In the final
expansion, include the awk functions.

* txr.1: Updated documentation to consistently call
prn an awk function everywhere.

1 files changed, 47 insertions, 39 deletions

diff --git a/share/txr/stdlib/awk.tl b/share/txr/stdlib/awk.tl
index d36426f3..b6f26c01 100644
--- a/share/txr/stdlib/awk.tl
+++ b/share/txr/stdlib/awk.tl
@@ -238,7 +238,7 @@
          awc.cond-actions (nreverse awc.cond-actions))
     awc))
 
-(defmacro sys:awk-let (awc aws-sym . body)
+(defmacro sys:awk-mac-let (awc aws-sym . body)
   ^(symacrolet ((rec (rslot ,aws-sym 'rec 'rec-to-f))
                 (orec (rslot ,aws-sym 'orig-rec 'rec-to-f))
                 (f (rslot ,aws-sym 'fields 'f-to-rec))
@@ -255,7 +255,6 @@
                 (ors (qref ,aws-sym ors)))
      (macrolet ((next () '(return-from :awk-rec))
                 (next-file () '(return-from :awk-file))
-                (prn (. args) ^(qref ,',aws-sym (prn ,*args)))
                 (sys:rng (from-expr to-expr :env e)
                   (let ((ix (pinc (qref ,awc nranges)))
                         (rng-temp (gensym))
@@ -296,6 +295,14 @@
                   ^(sys:awk-redir ,',aws-sym *stdin* :inp "w" ,path ,body)))
        ,*body)))
 
+(defmacro sys:awk-fun-let (aws-sym . body)
+  ^(flet ((prn (. args)
+            (qref ,aws-sym (prn . args))))
+     ,*body))
+
+(defun sys:awk-fun-shadowing-env (up-env)
+  (make-env nil '((prn . sys:special)) up-env))
+
 (defmacro awk (:env e . clauses)
   (let ((awc (sys:awk-expander clauses)))
     (with-gensyms (aws-sym awk-begf-fun awk-fun awk-endf-fun awk-retval)
@@ -303,43 +310,44 @@
                                                     ,*@rest))
                                            awc.cond-actions))
              (p-actions-xform (sys:expand
-                                ^(sys:awk-let ,awc ,aws-sym
+                                ^(sys:awk-mac-let ,awc ,aws-sym
                                    ,*p-actions-xform-unex)
-                                e)))
+                                (sys:awk-fun-shadowing-env e))))
         ^(block ,(or awc.name 'awk)
-           (let* (,*awc.lets ,awk-retval)
-             (sys:awk-let ,awc ,aws-sym
-               (let* ((,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))))
-                      ,*(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* (,*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
+                 (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)
+                                          ,(if awc.rng-exprs
+                                             ^(let* ((,awc.rng-rec-temp rec)
+                                                 ,*(nreverse
+                                                     (zip awc.rng-expr-temps
+                                                          awc.rng-exprs)))
+                                                ,p-actions-xform)
+                                             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)
-                                        ,(if awc.rng-exprs
-                                           ^(let* ((,awc.rng-rec-temp rec)
-                                               ,*(nreverse
-                                                   (zip awc.rng-expr-temps
-                                                        awc.rng-exprs)))
-                                              ,p-actions-xform)
-                                           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)))))))))