compiler: implement return-from and return.

* share/txr/stdlib/compiler.tl (compiler compile): Handle
return and return-from special forms.
(compiler comp-return-from, compiler comp-return): New
methods.

1 files changed, 18 insertions, 0 deletions

diff --git a/share/txr/stdlib/compiler.tl b/share/txr/stdlib/compiler.tl
index e6f7acda..b01482b5 100644
--- a/share/txr/stdlib/compiler.tl
+++ b/share/txr/stdlib/compiler.tl
@@ -162,6 +162,8 @@
             (cond me.(comp-cond oreg env form))
             (if me.(comp-if oreg env form))
             (block me.(comp-block oreg env form))
+            (return-from me.(comp-return-from oreg env form))
+            (return me.(comp-return oreg env form))
             ((let let*) me.(comp-let oreg env form))
             (lambda me.(comp-lambda oreg env form))
             (sys:for-op me.(comp-for oreg env form))
@@ -326,6 +328,22 @@
                  bfrag.fvars
                  bfrag.ffuns)))))
 
+(defmeth compiler comp-return-from (me oreg env form)
+  (mac-param-bind form (op name value) form
+    (let* ((nreg (if (null name)
+                   nil
+                   me.(get-dreg name)))
+           (vfrag me.(compile oreg env value)))
+      (new (frag oreg
+                 ^(,*vfrag.code
+                   (ret ,nreg ,vfrag.oreg))
+                 vfrag.fvars
+                 vfrag.ffuns)))))
+
+(defmeth compiler comp-return (me oreg env form)
+  (mac-param-bind form (op value) form
+    me.(comp-return-from oreg env ^(,op nil ,value))))
+
 (defmeth compiler comp-let (me oreg env form)
   (mac-param-bind form (sym raw-vis . body) form
     (let* ((vis (mapcar [iffi atom list] raw-vis))