diff options
Diffstat (limited to 'share')
| -rw-r--r-- | share/txr/stdlib/ifa.tl | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/share/txr/stdlib/ifa.tl b/share/txr/stdlib/ifa.tl index f7c4fcb0..180e5231 100644 --- a/share/txr/stdlib/ifa.tl +++ b/share/txr/stdlib/ifa.tl @@ -29,15 +29,23 @@ (cond ((or (atom test) (null (cdr test))) ^(let ((it ,test)) (if it ,then ,else))) - ((member (first test) '(not null)) ^(ifa ,(second test) ,else ,then)) + ((member (first test) '(not null false)) + (unless (eql (length test) 2) + (throwf 'eval-error "ifa: wrong number of arguments to ~s" + (first test))) + ^(ifa ,(second test) ,else ,then)) (t (let* ((sym (first test)) (args (rest test)) (n-candidate-args [count-if candidate-p args]) (pos-candidate (or [pos-if candidate-p args] 0))) - (unless (fboundp sym) - (error "ifa: only works with global functions.")) + (unless (or (lexical-fun-p e sym) + (and (or (functionp (symbol-function sym)) + (null (symbol-function sym))))) + (throwf 'eval-error "ifa: test expression must be \ + \ a simple function call")) (when (> n-candidate-args 1) - (error "ifa: ambiguous situation: not clear what can be \"it\".")) + (throwf 'eval-error "ifa: ambiguous situation: \ + \ not clear what can be \"it\"")) (let* ((temps (mapcar (ret (gensym)) args)) (it-temp [temps pos-candidate])) ^(let* (,*(zip temps args) (it ,it-temp)) |