Brent Pinkney wrote:

Hi,

What is the expected result of

[ 1 / 0 ] ifCurtailed: [ 2 ]

I had thought #ifCurtailed: was used to catch any exceptions?

No, #ifCurtailed: is used to execute cleanup code *if the execution of the method won't continue past the #ifCurtailed: itself*. This can surely happen because of an exception, but also because the block, or something it calls, does a return-from-method. For example,

[ ^1 ] ifCurtailed: [ Transcript show: 'yeppp' ].

will execute the #ifCurtailed: block too.

#ifCurtailed: could be implemented like this in terms of #ensure:

ifCurtailed: curtailBlock | result curtailed | curtailed := true. [ result := self value. curtailed := false ] ensure: [ curtailed ifTrue: [ curtailBlock value ] ]. ^result

Dually, #ensure: could be implemented like this using #ifCurtailed:

ensure: ensureBlock | result | result := self ifCurtailed: ensureBlock. "If we come here, execution was not curtailed and ensureBlock has not been executed yet." ensureBlock value. ^result

Paolo