Note: no need for #collect:thenFold: family, one can implement min as min ^ self detectMin: [ :x | x ] if you want to reuse existing one. But actually, the issue is, min: and max: are not there (correctly) for strings. Herby Richard O'Keefe wrote:
#('a' 'b' 'c') min also fails on the grounds that ByteStrings don't understand #min:. What's worse is that ByteString and ByteSymbol *do* have #max:, but it's something quite different (and arguably broken).
max: aBlock | max | self ifEmpty: [ ^ nil ]. max := aBlock value: self first. self allButFirstDo: [ :each | | value | value := aBlock value: each. max := max max: value ]. ^ max
It would be better if the TComparable #min: and #max: were available and the current #max: renamed to something else. I have this in an extension to GNU Smalltalk:
Collection extend [ collect: collectBlock thenFold: foldBlock [ |started result| started := result := nil. self do: [:each | |v| v := collectBlock value: each. result := started ifNil: [started := self. v] ifNotNil: [foldBlock value: result value: v]]. ^started ifNil: [SystemExceptions.EmptyCollection signalOn: self] ifNotNil: [result] ]
collectThenMin: collectBlock [ ^self collect: collectBlock thenFold: [:acc :y | acc min: y] ] min [ ^self collectThenMin: [:each | each] ]
collectThenMax: collectBlock [ ^self collect: collectBlock thenFold: [:acc :y | acc max: y] ] max [ ^self collectThenMax: [:each | each] ] ]
CharacterArray extend [ max: other [ ^self < other ifTrue: [other] ifFalse: [self] ]
min: other [ ^self < other ifTrue: [self] ifFalse: [other] ] ]