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| author | Kaz Kylheku <kaz@kylheku.com> | 2015-10-29 06:46:05 -0700 |
|---|---|---|
| committer | Kaz Kylheku <kaz@kylheku.com> | 2015-10-29 06:46:05 -0700 |
| commit | 2764d8e78d0d72f7c0d8fcc4e41cf4df41017026 (patch) | |
| tree | 4e6a9264ad0261282fd5bee6c6f7d47da798c35a /share | |
| parent | d651ee10089e684686d9255e6f479fa16c7576db (diff) | |
| download | txr-2764d8e78d0d72f7c0d8fcc4e41cf4df41017026.tar.gz txr-2764d8e78d0d72f7c0d8fcc4e41cf4df41017026.tar.bz2 txr-2764d8e78d0d72f7c0d8fcc4e41cf4df41017026.zip | |
Finalize obtain continuator function.
* share/txr/stdlib/yield.tl (sys:obtain-impl): Add a finalizer
to the returned closure which will feed sys:cont-poison object
to the most recently captured continuation. Thus abandoned
obtain blocks which have become garbage shall have their
unwinding performed.
* txr.1: Documented the finalization behavior.
Diffstat (limited to 'share')
| -rw-r--r-- | share/txr/stdlib/yield.tl | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/share/txr/stdlib/yield.tl b/share/txr/stdlib/yield.tl index ef0518e6..ea9bb4d2 100644 --- a/share/txr/stdlib/yield.tl +++ b/share/txr/stdlib/yield.tl @@ -26,13 +26,16 @@ (defstruct (sys:yld-item val cont) nil val cont) (defun sys:obtain-impl (fun) - (lambda (: reply) - (let ((yi (call fun reply))) - (cond - ((eq (typeof yi) 'sys:yld-item) - (set fun yi.cont) - yi.val) - (t yi))))) + (finalize + (lambda (: reply) + (let ((yi (call fun reply))) + (cond + ((eq (typeof yi) 'sys:yld-item) + (set fun yi.cont) + yi.val) + (t yi)))) + (lambda (cont) + (call cont 'sys:cont-poison)))) (defun sys:yield-impl (name fun ctx-form) (let ((cont (sys:capture-cont name ctx-form))) |