[perl #130876] [BUG] repl error report suppressed by prior output
On Mon, 27 Feb 2017 16:53:02 -0800, zef...@fysh.org wrote: > Zoffix Znet via RT wrote: > >Fix: https://github.com/rakudo/rakudo/commit/61a65cee3d > > You've just moved the problem along. There's now a new class of > object that, if evaluated to, will be treated as if evaluation failed on > exception. Successful evaluation can yield literally any value, so if you > want to represent the disjunction of an evaluation result with something > that's not an evaluation result then you can't have evaluation results > just represented as themselves. That doesn't leave any distinct values > to represent the other things. You need more structure: for example, > your single $output value could be a list of the form (True, $value) > to represent a normal evaluation result and (False, $ex) to represent > evaluation terminating by exception. > > -zefram > Thanks. Fixed now. Note that your proposal wouldn't work, as it's possible to fill out the exception variable by returning a two-item Slip as the output. Fix: https://github.com/rakudo/rakudo/commit/7f9235c79d Tests: https://github.com/rakudo/rakudo/commit/7f9235c79d
Re: [perl #130876] [BUG] repl error report suppressed by prior output
Zoffix Znet via RT wrote: >Fix: https://github.com/rakudo/rakudo/commit/61a65cee3d You've just moved the problem along. There's now a new class of object that, if evaluated to, will be treated as if evaluation failed on exception. Successful evaluation can yield literally any value, so if you want to represent the disjunction of an evaluation result with something that's not an evaluation result then you can't have evaluation results just represented as themselves. That doesn't leave any distinct values to represent the other things. You need more structure: for example, your single $output value could be a list of the form (True, $value) to represent a normal evaluation result and (False, $ex) to represent evaluation terminating by exception. -zefram
[perl #130876] [BUG] repl error report suppressed by prior output
On Mon, 27 Feb 2017 14:27:04 -0800, zef...@fysh.org wrote:
> Zoffix Znet via RT wrote:
> >Fix: https://github.com/rakudo/rakudo/commit/db70a1fda8
>
> This doesn't distinguish between an exception being thrown and the
> expression evaluating to an exception object. The former is an error
> condition that must be reported; the latter is a successful evaluation
> in the same category as evaluating to a string. Incorrect behaviour
> (failing to suppress output of a normal evaluation which produced its
> own output) can be seen thus:
>
> > say 123; try { my Int $a; $a = "foo" }; say 456; $!
> 123
> 456
> Type check failed in assignment to $a; expected Int but got Str ("foo")
> in block at line 1
>
> Your single $output variable is too narrow to make the distinctions that
> you need.
>
> -zefram
>
Thanks for catching that one. Fixed now.
Fix: https://github.com/rakudo/rakudo/commit/61a65cee3d
Tests: https://github.com/rakudo/rakudo/commit/61a65cee3d
Re: [perl #130876] [BUG] repl error report suppressed by prior output
Zoffix Znet via RT wrote:
>Fix: https://github.com/rakudo/rakudo/commit/db70a1fda8
This doesn't distinguish between an exception being thrown and the
expression evaluating to an exception object. The former is an error
condition that must be reported; the latter is a successful evaluation
in the same category as evaluating to a string. Incorrect behaviour
(failing to suppress output of a normal evaluation which produced its
own output) can be seen thus:
> say 123; try { my Int $a; $a = "foo" }; say 456; $!
123
456
Type check failed in assignment to $a; expected Int but got Str ("foo")
in block at line 1
Your single $output variable is too narrow to make the distinctions that
you need.
-zefram
[perl #130876] [BUG] repl error report suppressed by prior output
On Mon, 27 Feb 2017 00:21:17 -0800, zef...@fysh.org wrote: > > say "a"; "a" + 2; say "b" > a > > "a" + 2 > Cannot convert string to number: base-10 number must begin with valid > digits or '.' in '^a' (indicated by ^) > in block at line 1 > > In both of these cases the addition signals an exception, terminating > the evaluation phase of the repl. But the exception is only reported > in > the second case. The behaviour in the first case, with the exception > going unreported, is quite confusing in any case less obvious than > this example. The criterion determining whether the exception gets > reported is whether the evaluation has sent anything to the output > stream. > This is obviously the same logic that's being used to suppress > printing > the result of evaluation: it's OK to suppress that, but silly to also > suppress error reports. > > -zefram Thank you for the report. This is now fixed. Fix: https://github.com/rakudo/rakudo/commit/db70a1fda8 Tests: https://github.com/rakudo/rakudo/commit/db70a1fda8
[perl #130876] [BUG] repl error report suppressed by prior output
# New Ticket Created by Zefram # Please include the string: [perl #130876] # in the subject line of all future correspondence about this issue. # https://rt.perl.org/Ticket/Display.html?id=130876 > > say "a"; "a" + 2; say "b" a > "a" + 2 Cannot convert string to number: base-10 number must begin with valid digits or '.' in '^a' (indicated by ^) in block at line 1 In both of these cases the addition signals an exception, terminating the evaluation phase of the repl. But the exception is only reported in the second case. The behaviour in the first case, with the exception going unreported, is quite confusing in any case less obvious than this example. The criterion determining whether the exception gets reported is whether the evaluation has sent anything to the output stream. This is obviously the same logic that's being used to suppress printing the result of evaluation: it's OK to suppress that, but silly to also suppress error reports. -zefram
