CODEWITHSUNDEEP
haskellghci
Dan Burton
Dan Burton

Reputation: 53665

A ghci session without Prelude

This question arose on #haskell irc chat:

How can I start ghci without importing prelude?

The possible answer seemed obvious:

ghci -XNoImplicitPrelude, or load a file with import Prelude ()

The latter seems to work, while the former strangely does not. However, import Prelude () imports the declared instances from Prelude, right? Is there a better way of creating a ghci session without loading Prelude at all?

Upvotes: 22

Views: 2711

Answers (2)

Qwertie
Qwertie

Reputation: 6493

The accepted answer doesn't seem to work anymore. This does work in ghci 8.0.2.

Prelude> :set -XNoImplicitPrelude
Prelude> :m -Prelude
>

Upvotes: 4

Roman Cheplyaka
Roman Cheplyaka

Reputation: 38708

% ghci                    
GHCi, version 7.0.4: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Loading package ffi-1.0 ... linking ... done.
Prelude> :m -Prelude 
> :i map

Top level: Not in scope: `map'
> :i Eq

Top level: Not in scope: data constructor `Eq'

However, I'm not sure about the instances and how ghci deals with them.

Is there a particular instance that you're concerned about?

Upvotes: 17

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