New special operator: progv

Adding a progv operator, similar to the Common Lisp one.

* eval.c (progv_s): New symbol variable.
(op_progv): New static function.
(do_expand): Recognize and traverse the progv form.
(rt_progv): New static function: run-time support
for compiled progv.
(eval_init): Initialize progv_s, and register the the
op_progv operator interpreting function.

* stdlib/compilert (compiler compile): Handle progv
operator ...
(compiler comp-progv): ... via this new method.

* tests/019/progv.tl: New file.

* txr.1: Documented.

* stdlib/doc-syms.tl: Updated.

1 files changed, 29 insertions, 0 deletions

diff --git a/tests/019/progv.tl b/tests/019/progv.tl
new file mode 100644
index 00000000..7ab3aafe
--- /dev/null
+++ b/tests/019/progv.tl
@@ -0,0 +1,29 @@
+(load "../common")
+
+(defvar a 42)
+(defvar b 73)
+
+(mtest
+  (progv '(a) '(1) a) 1
+  (progv '(a b) '(1 2) (cons a b)) (1 . 2)
+  (progv '(x) '(1) (let ((x 4)) (symbol-value 'x))) 1)
+
+(let ((n (list 'a 'b))
+      (v (list 1 2)))
+  (mtest
+    (progv n v (cons a b)) (1 . 2)))
+
+(defvarl x)
+
+(let ((x 'lexical)
+     (vars (list 'x))
+     (vals (list 'dynamic)))
+  (test
+    (progv vars vals (list x (symbol-value 'x)))
+    (lexical dynamic)))
+
+(compile-only
+  (eval-only
+    (with-compile-opts (nil unused)
+      (compile-file (base-name *load-path*) "temp.tlo"))
+    (remove-path "temp.tlo")))