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| author | Kaz Kylheku <kaz@kylheku.com> | 2015-08-10 06:43:37 -0700 |
|---|---|---|
| committer | Kaz Kylheku <kaz@kylheku.com> | 2015-08-10 06:43:37 -0700 |
| commit | f2a2306a8bd6fb86b4819875f752e3a836f1533d (patch) | |
| tree | 8fd5b8b11f6d114d13d8414511b134a7251f7991 /share | |
| parent | c9f9e9419a485b383da3229ca130fdd820db3f33 (diff) | |
| download | txr-f2a2306a8bd6fb86b4819875f752e3a836f1533d.tar.gz txr-f2a2306a8bd6fb86b4819875f752e3a836f1533d.tar.bz2 txr-f2a2306a8bd6fb86b4819875f752e3a836f1533d.zip | |
Diagnose bad consing dot syntax like (a . b . c).
* parser.y (r_exprs): Use unique object in the terminating cons to
indicate the empty spot where the dotted cdr item will go. Check for
misplaced consing dot. (misplaced_consing_dot_check): New static
function. Checks for the terminator atom spot being taken already.
Thus, the spot may be taken only by the very last reduction, such that
the next reduction is r_exprs -> n_exprs where the terminating atom is
processed.
* parser.c (unique_s): New global variable.
(parse_init): Initialize unique_s.
* parser.h (unique_s): Declared.
* share/txr/stdlib/place.tl (sys:placelet-1): We have a misplaced
consing dot here! It was working correctly by "terminating atom
propagation" behavior, which allowed (a . b c d) to produce
(a c d . b). If a single terminating atom occurred in the middle of a list, it
was promoted to the end.
Diffstat (limited to 'share')
| -rw-r--r-- | share/txr/stdlib/place.tl | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/share/txr/stdlib/place.tl b/share/txr/stdlib/place.tl index 398ecbe3..270baace 100644 --- a/share/txr/stdlib/place.tl +++ b/share/txr/stdlib/place.tl @@ -600,7 +600,7 @@ (with-update-expander (getter setter) ,place-sym env ^(,setter (,',function (,getter) ,,*cleaned-lambda-list))))))) -(defmacro sys:placelet-1 (((sym place)) . body :env env) +(defmacro sys:placelet-1 (((sym place)) :env env . body) (with-gensyms (tmp-place pl-getter pl-setter steal-getter) (unwind-protect (progn |