Colin I'm continuing adding comments to FS. 1- A question about FSPath class>>* aString ^ self with: aString I would like to deprecated FSPath class>>* and use with: since this is the message and What do you think? I really prefer for static analysis point of view not to pollute numerical behavior with others. Avoiding ad-hoc polymorphism will help us to build static checker in the future. 2- Then I was wondering if it would not be good to have validating creation methods (FSPath * 'parent/child/') isRelative true (FSPath * '/parent/child/') isAbsolute false because the string is not checked FSPath * '/parejhkjhhg %% ^%$%^(%$546547675 nt??child/' I saw that there is readFrom: aStream delimiter: aCharacter so I created an unchecking instance creation category and I added with: and * in it. And added comments 3- Then finally the following confuses me (FSPath with: 'parent/child/') isRelative true (FSPath with: '/parent/child/') isRelative true (FSPath with: '') isRelative false Either with: create relative path or isRelative is not consistent. If with: creates relative path then the last one should be true or isRelative should return false on the second one. ? 4 - about FSPath root we have root "Return the relative root path" ^ self with: '' FSPath root returns / and I like that Now what about defining root as root ^ self with: '/' It would be more consistent. Now it breaks everything. So I did not do it :) May be I'm tired after 4 ours teaching and 6 hours train. Thanks for your time Stef