[Haskell-cafe] MonadFix wiki confusion

Samuel Rødal srodal at gmail.com
Sun Oct 18 14:40:19 UTC 2015


the MonadFix wiki at https://wiki.haskell.org/MonadFix has a statement
that I feel is a bit misleading.

In section "2.2 Lazy algorithm interleaved with effects", it claims
that making the BTree data structure strict doesn't cause endless

Well, that's true, but that's just because rep_x_sum returns a tuple
containing the BTree and the summed values of the current subtree, and
the tuple is lazily constructed - postponing the construction of the
tree value. So highlighting the fact that the function still works
when the BTree structure is made strict is kind of a red herring.

Maybe the confusion could be avoided by removing the part about making
BTree strict, or adding a note about the tuple still ensuring lazy


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