Difference between revisions of "No import of Prelude"
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== Question == |
== Question == |
||
− | Is it possible to not load the Prelude |
+ | Is it possible to not load the Prelude when compiling a Haskell module? |
== Answer == |
== Answer == |
Revision as of 02:49, 4 December 2010
Question
Is it possible to not load the Prelude when compiling a Haskell module?
Answer
You can either do
import Prelude()
or add
{-# LANGUAGE NoImplicitPrelude #-}
to the top of the module, or equivalently compile with -fno-implicit-prelude
option.
import Prelude()
is less aggressive than NoImplicitPrelude
.
E.g. with the first method some functions are imported which are silently inserted for several syntactic constructs.
A bare untyped integral number is rewritten as fromIntegral num
(so its type will be Num a => a
),
and list generation syntax is rewritten as follows:
[n..]
enumFrom
,
[n..m]
enumFromTo
,
[n,o..]
enumFromThen
,
[n,o..m]
enumFromThenTo
.
There are some such for which even -fno-implicit-prelude
isn't enough;
I think these are documented in the "bugs" section of the GHC manual.
See also
- Haskell-Cafe: Not to load Prelude