diff options
| -rw-r--r-- | share/txr/stdlib/with-resources.tl | 10 | ||||
| -rw-r--r-- | txr.1 | 41 |
2 files changed, 36 insertions, 15 deletions
diff --git a/share/txr/stdlib/with-resources.tl b/share/txr/stdlib/with-resources.tl index eb061066..5c1b8130 100644 --- a/share/txr/stdlib/with-resources.tl +++ b/share/txr/stdlib/with-resources.tl @@ -26,15 +26,15 @@ (defmacro with-resources (:form f res-bindings . body) (tree-case res-bindings - (((sym init cleanup) . rest) + (((sym init) . rest) + ^(let ((,sym ,init)) + (with-resources ,rest ,*body))) + (((sym init . cleanup) . rest) ^(let ((,sym ,init)) (when ,sym (unwind-protect (with-resources ,rest ,*body) - ,cleanup)))) - (((sym init) . rest) - ^(let ((,sym ,init)) - (with-resources ,rest ,*body))) + ,*cleanup)))) ((sym . rest) ^(let (,sym) (with-resources ,rest ,*body))) @@ -41539,7 +41539,7 @@ only the exception arguments are passed to the clauses of .coNP Macro @ with-resources .synb -.mets (with-resources >> ({ sym >> [ init-form <> [ cleanup-form ])}*) +.mets (with-resources >> ({ sym >> [ init-form <> [ cleanup-form *])}*) .mets \ \ << body-form *) .syne .desc @@ -41567,27 +41567,48 @@ is bound to the value If an .meta init-form is supplied, but no -.metn cleanup-form , +.metn cleanup-form -s, then .meta sym is bound to the value of the .metn init-form . -If a -.meta cleanup-form -is supplied in addition to +If one or more +.metn cleanup-form -s +are supplied in addition to .metn init-form , -it specifies code to be executed upon the termination of the -entire +they specifies forms to be executed upon the termination of the .code with-resources construct. When an instance of .code with-resources -terminates, all of the +terminates, either normally or by a non-local control transfer, +then for each +.meta sym +whose +.meta init-form +had executed, thus causing that +.code sym +to be bound to a value, the .metn cleanup-form -s -specified in its binding clauses are evaluated, in reverse (right-to-left) -order. The value of the last +corresponding to +.meta sym +are evaluated in the usual left-to-right order. + +The +.metn sym -s +are cleaned up in reverse (right-to-left) order. The +.metn cleanup-form -s +of the most recently bound +.meta sym +are processed first; those of the least recently bound +.meta sym +are processed last. + +When the +.code with-resources +form terminates normally, the value of the last .meta body-form is returned, or else .code nil |