DNU to get/set inst vars

gistfile1.st

doesNotUnderstand: aMessage
    "gets or sets an instance variable"

    | argCount getters key setters value index |

    argCount := aMessage numArgs.
    argCount > 1 ifTrue: [ ^super doesNotUnderstand: aMessage ].

    key := aMessage keywords first.

    getters := self class allInstVarNames.
    index := getters indexOf: key.
    index > 0 ifTrue: [^self instVarAt: index].

    setters := getters collect: [ :name | name, ':' ].
    index := setters indexOf: key.
    index > 0 ifTrue: [
        value := aMessage arguments first.
        ^self instVarAt: index put: value].

    ^super doesNotUnderstand: aMessage