Custom Query (1030 matches)

Dan Weinreb 2010-05-07 16:29:48 EDT

In a case such as this:

(defun foo (x y)
  (handler-case
      (/ x y)
    ((error serious-condition) ()
      5)))

it would be nice if the compiler could detect that (error serious-condition) is not a valid type (i.e. the programmer omitted the "or").

In

(defun bar (x)
  (check-type x (error serious-condition))
  x)

the compiler does, correctly, issue a warning; could that same mechanism be applied to handler-case?

NB: This was ITA bug 79938.

Ethan H. Schwartz 2009-05-03 16:41:00 EDT

Observe:

Welcome to Clozure Common Lisp Version 1.3-dev-r11962-working-0711 
(LinuxX8664)!
? (defun foo1 () #'bar1)
FOO1
? (defun foo2 () #'common-lisp::bar2)
FOO2
? (defun foo3 () #'common-lisp:bar3)

> Error: Reader error: No external symbol named "BAR3" in package #<Package "COMMON-LISP"> .

Note that FOO1 and FOO2 will both error at runtime.  CCL should have warned
when defining those functions as well.

Compiling a file with this contents:

(prog1
    (declare (ignore foo)))

yields a confusing error message

Welcome to Clozure Common Lisp Version 1.2-r9226-RC1  (LinuxX8664)!
? (compile-file "foo.lisp")
;Compiler warnings for "/home/hans/profiler/foo.lisp" :
;   In an anonymous lambda form: DECLARE not expected in (DECLARE (IGNORE FOO))
> Error: No MAKE-LOAD-FORM method is defined for #<CCL::SIMPLE-PROGRAM-ERROR #x
00040CFAF3D>

The "DECLARE not expected" is clear, but the MAKE-LOAD-FORM thing is really confusing. It seems as if the compiler continues when it can't.