[source]

compiler/coreSyn/PprCore.hs

Note [Print case as let]

[note link]

Single-branch case expressions are very common:

case x of y { I# x’ -> case p of q { I# p’ -> … } }

These are, in effect, just strict let’s, with pattern matching. With -dppr-case-as-let we print them as such:

let! { I# x’ ~ y <- x } in let! { I# p’ ~ q <- p } in …

Other printing bits-and-bobs used with the general @pprCoreBinding@ and @pprCoreExpr@ functions.

Note [Binding-site specific printing]

[note link]

pprCoreBinder and pprTypedLamBinder receive a BindingSite argument to adjust the information printed.

Let-bound binders are printed with their full type and idInfo.

Case-bound variables (both the case binder and pattern variables) are printed without a type and without their unfolding.

Furthermore, a dead case-binder is completely ignored, while otherwise, dead binders are printed as “_”.

These instances are sadly orphans