Hi all,

would you mind if I merged these changes (#haltOnceIf:)? As they have worked well for me so far, I will merge them next week if no one objects. See also KernelTests-ct.374. :-)

Best,
Christoph

---
Sent from Squeak Inbox Talk

On 2020-01-09T14:42:46+00:00, commits@source.squeak.org wrote:

> A new version of Kernel was added to project The Inbox:
> http://source.squeak.org/inbox/Kernel-ct.1294.mcz
>
> ==================== Summary ====================
>
> Name: Kernel-ct.1294
> Author: ct
> Time: 9 January 2020, 3:42:36.672555 pm
> UUID: 7409dcc3-160e-9d44-9712-f266e0f25973
> Ancestors: Kernel-nice.1292
>
> Proposal: Add #haltOnceIf: to Object, which combines the strengths of #haltOnce and #haltIf:. Especially useful in performance-critical situations: It HaltOnce is disabled, the condition will not be evaluated at all.
>
> =============== Diff against Kernel-nice.1292 ===============
>
> Item was changed:
> ----- Method: Object>>haltIf: (in category 'debugging') -----
> + haltIf: aCondition
> +     "This is the typical message to use for inserting breakpoints during debugging. Param can be a block or expression, halt if true.
> - haltIf: condition
> -     "This is the typical message to use for inserting breakpoints during
> -     debugging. Param can be a block or expression, halt if true.
>     If the Block has one arg, the receiver is bound to that.
> +     If the condition is a selector, we look up in the callchain. Halt if any method's selector equals selector."
> -     If the condition is a selector, we look up in the callchain. Halt if
> - any method's selector equals selector."
> -     | cntxt |
>
> +     ^ (self meetsHaltCondition: aCondition)
> +         ifTrue: [self halt]!
> -     condition isSymbol ifTrue:[
> -         "only halt if a method with selector symbol is in callchain"
> -         cntxt := thisContext.
> -         [cntxt sender isNil] whileFalse: [
> -             cntxt := cntxt sender.
> -             (cntxt selector = condition) ifTrue: [Halt signal].
> -             ].
> -         ^self.
> -     ].
> -     (condition isBlock
> -             ifTrue: [condition cull: self]
> -             ifFalse: [condition]
> -     ) ifTrue: [
> -         Halt signal
> -     ].!
>
> Item was added:
> + ----- Method: Object>>haltOnceIf: (in category 'debugging') -----
> + haltOnceIf: aCondition
> +     "Check aCondition and halt, unless we have already done it once. See #meetsHaltCondition:."
> +     
> +     self haltOnceEnabled ifFalse: [^ self].
> +     ^ (self meetsHaltCondition: aCondition)
> +         ifTrue: [
> +             self clearHaltOnce; halt].!
>
> Item was added:
> + ----- Method: Object>>meetsHaltCondition: (in category 'debugging') -----
> + meetsHaltCondition: aCondition
> +     "If the Block has one arg, the receiver is bound to that.
> +     If the condition is a selector, we look up in the callchain. Halt if any method's selector equals selector."
> +     
> +     aCondition isSymbol ifTrue: [ | ctxt |
> +         "only halt if a method with selector symbol is in callchain"
> +         ctxt := thisContext.
> +         [(ctxt := ctxt sender) isNil] whileFalse: [
> +             (ctxt selector = aCondition) ifTrue: [^ true] ].
> +         ^ false ].
> +     ^ aCondition isBlock
> +             ifTrue: [aCondition cull: self]
> +             ifFalse: [aCondition value]!
>
>