The Inbox: Kernel-ct.1294.mcz

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]!