[Haskell-cafe] Haskell interface files: Why used? What about same
data in object files?
malcolm.wallace at cs.york.ac.uk
Tue Aug 4 07:43:46 EDT 2009
> I am trying to understand the design of the Haskell interface files.
> are they a separate file rather than having the same data in the
> file generated by the compiler? (Naively, it seems to me this would
> also. Am I missing something?)
Placing interface information into object files would be a perfectly
reasonable design decision for a compiler. The language standard
itself does not mandate the use of interface files (although it did
once, around Haskell 1.2), nor any particular format, so a compiler is
free to use whatever strategy it wishes.
Some good reasons for having a separate interface are: they can be
human-readable and human-writable (ghc's do not fulfill this
criterion); they can be used to bootstrap mutually recursive modules
in the absence of any object files (ghc uses .hs-boot files instead);
other tools can extract information about modules without having to
understand either the full Haskell syntax or the object language.
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