Andrew J Bromage
G'day all.
On Wed, Feb 05, 2003 at 04:16:33PM -0800, Iavor S. Diatchki wrote:
why do you think separate compilation is difficult to achieve in Haskell 98?
Because of type inference over recursive module imports. Determining the type of a function may, in general, require inferring types from an arbitrary number of other modules, and may require inference to occur at the level of granularity of a clique in the import graph, rather than at the level of a single module.
Requiring an implementation to perform static analysis a clique at a time is not "separate compilation", because changing something which is private to one module may in general require an unbounded number of other modules to be recompiled, even if inter-module optimisation is turned off.
I'm not sure I follow this. If you change the type of a value exported from a given module, that's a public change, no? And if you don't, why should re-compilation be needed? <snip>
Cheers, Andrew Bromage
Jon Cast