The behaviour exhibited by your examples can
be explained by the following:
a. A value error is signalled if the definition of
a verb is needed but that verb is undefined:
undefined + 1
|value error: undefined
| undefined+1
b. An undefined name is treated as a verb and,
unless its definition is needed, is not an error:
3 : ('undefined';'3+4') 5
7
c. A syntax error is signalled if a verb returns
a verb result.
3 : ('3+4';'*') 5
|syntax error
| 3 :('3+4';'*')5
p.s. Are you really based in Zambia, or is it just where
your ISP is located?
----- Original Message -----
From: "Jeff.Mosmann" <[EMAIL PROTECTED]>
Date: Tuesday, April 22, 2008 8:33
Subject: [Jprogramming] try. B0 catch. B1 end.
To: [email protected]
> I have come across a situation where < try. B0 catch. B1 end.
> > appears to
> behave inappropriately.
>
>
>
> If the rightmost element of B0 is an undefined name, the
> expected value
> error is not caught, but breaks the control structure with a
> syntax error.
>
>
>
> If, however, there is another element to the right of the
> undefined name,
> then the structure behaves as expected and B1 is executed.
>
>
>
> With J602 / Windows XP / Intel Pentium M,
>
>
>
> case0=: 3 : 'try. notdefined
> catch. ''breaks'' end.'
>
>
>
> case0 ‘’
>
> |syntax error: case0
>
> | case0''
>
>
>
> case1=: 3 : 'try. 1+ notdefined catch. ''also
> breaks'' end.'
>
>
>
> case1 ‘’
>
> |syntax error: case1
>
> | case1''
>
>
>
> case2=: 3 : 'try. notdefined +1 catch. ''but
> this works!'' end.'
>
>
>
> case2 ''
>
> but this works!
>
>
>
> Is this a bug? Or have I missed something ….. ?
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