Hi Ben, On Fri, Nov 1, 2013 at 7:01 AM, Benjamin < Benjamin.VanRyseghem.Pharo@gmail.com> wrote:

Hello guys,

is it expected that

1 perform: #gcd: withArguments: {2} works

while

1 perform: #gcd: withArguments: {2} asOrderedCollection fails ?

As Alexandre explained it's because the VM insists on an Array. But there is a neat way to solve this. e.g. if the method is defined as Object>>perform: selector withArguments: argArray "Send the selector, aSymbol, to the receiver with arguments in argArray. Fail if the number of arguments expected by the selector does not match the size of argArray. Primitive. Optional. See Object documentation whatIsAPrimitive." <primitive: 84> ^ self perform: selector withArguments: argArray inSuperclass: self class and Object>>perform: selector withArguments: argArray inSuperclass: lookupClass "NOTE: This is just like perform:withArguments:, except that the message lookup process begins, not with the receivers's class, but with the supplied superclass instead. It will fail if lookupClass cannot be found among the receiver's superclasses. Primitive. Essential. See Object documentation whatIsAPrimitive." <primitive: 100> (selector isSymbol) ifFalse: [^ self error: 'selector argument must be a Symbol']. (selector numArgs = argArray size) ifFalse: [^ self error: 'incorrect number of arguments']. (self class == lookupClass or: [self class inheritsFrom: lookupClass]) ifFalse: [^ self error: 'lookupClass is not in my inheritance chain']. self primitiveFailed then redefine perform:withArguments:inSuperclass: to read something like: Object>>perform: selector withArguments: argArray inSuperclass: lookupClass "NOTE: This is just like perform:withArguments:, except that the message lookup process begins, not with the receivers's class, but with the supplied superclass instead. It will fail if lookupClass cannot be found among the receiver's superclasses. Primitive. Essential. See Object documentation whatIsAPrimitive." <primitive: 100> (argArray isCollection and: [argArray isSequenceable and: [argArray class ~~ Array]]) ifTrue: [^self perform: selector withArguments: argArray asArray inSuperclass: lookupClass]. selector isSymbol ifFalse: [^ self error: 'selector argument must be a Symbol']. selector numArgs = argArray size ifFalse: [^ self error: 'incorrect number of arguments']. (self class == lookupClass or: [self class inheritsFrom: lookupClass]) ifFalse: [^ self error: 'lookupClass is not in my inheritance chain']. self primitiveFailed c.f. e.g. the asInteger send in Object>>at: index "Primitive. Assumes receiver is indexable. Answer the value of an indexable element in the receiver. Fail if the argument index is not an Integer or is out of bounds. Essential. See Object documentation whatIsAPrimitive." <primitive: 60> index isInteger ifTrue: [self class isVariable ifTrue: [self errorSubscriptBounds: index] ifFalse: [self errorNotIndexable]]. index isNumber ifTrue: [^self at: index asInteger] ifFalse: [self errorNonIntegerIndex] which allows one to write #(seriously ?) at: 1.0 HTH, Eliot