Re: Extending the dependency syntax

On 8/10/05, Simon Marlow wrote:

On 10 August 2005 06:56, Brian Smith wrote:

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On 8/9/05, Simon Marlow wrote:

I'm not wildly excited about "true ? true", but we could add special syntax for that if it turns out to be used often.

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Can configurations contain their own "Build-depends", like this?:

[windows] Build-depends: Win32 extra-libraries: gnome

The problem I have with this is that it means you can only decide dependencies based on the settings of flags, rather than the other way around. We use both in the above example - [ghc64] is decided based on the availability of ghc versions, whereas [mozilla] is chosen based on a configuration flag. You had to hack it in your example:

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I think it would be clearer to specify the configuration seperately, like this:

configuration: ghc >= 6.4 ? [ghc64] | ghc >= 5.04 ? [ghc-old]) | hugs? [hugs], debug enabled ? [debug] | [release], gnome enabled ? [gnome], mozilla enabled ? [mozilla], doc enabled ? [doc] -- the "global" Build-depends applies to everything Build-depends: base >= 1.0, haskell98 >= 1.0

So configuration contains dependencies like ghc >= 6.4. I think it's clearer to put all the dependencies in one place.

Fair enough. But, you doesn't answer the original part of my question: can each configuration stanza contain its own "Build-depends" section too? Like I said, if a configuration stanza can contain _foreign library_ dependencies (e.g. Extra-libraries: shell32, libxml2) then it seems like we should be able to put _native library_ dependencies in the configuration stanzas too. Also, don't we need a way to version native library dependencies too? e.g. Extra-libraries: libxml2 >= 2.6.1. And then, do you want to allow conditional dependencies based on native library dependencies? And, if so, do you want them integrated into the Build-depends: field too? - Brian