[Haskell-cafe] GetOpt

[Brian Hulley]

Brian Hulley wrote:
> moduleOptions = ComposedOption "My module" [ModOption1, ModOption2]
moduleOptions = Option $ ComposedOption "My module" [ModOption1, ModOption2]

> allOptions = ComposedOption "Name of program" [Module1.moduleOptions,

allOptions = Option $ ComposedOption "Name of program" 
[Module1.moduleOptions,

Thinking more about it, it would be better to change the type of 
ComposedOption to:

    data ComposedOption = ComposedOption [(String, Option)]

since an option by itself can't tell what it's name should be because any 
name specified might conflict with other option names, but the parent can 
assign different names safely.
Also, many different schemes for composing options could be devised, so that 
some subsets of options would be indexed by a number instead of a letter 
etc.

Regards, Brian.

PS: this is definitely a good case for the use of augmented IO since the 
fact that a particular module needs to store option state should be 
completely invisible to the rest of the program...