Skip to content

the resolution of abbreviated commands in ghci is surprising.

GHCi, version 6.12.1: 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> :i True
data Bool = ... | True  -- Defined in GHC.Bool
Prelude> :def ifoo \_ -> putStrLn "ifoo" >> return ""
Prelude> :i True
ifoo

It seems that abbreviations are resolved to the command, that matches the prefix, which is defined last. I've found this behaviour very confusing in practice.

I'd expect rebinding :i to some command that's not :info to require an explicit declaration.

Trac metadata
Trac field Value
Version 6.12.1
Type Bug
TypeOfFailure OtherFailure
Priority normal
Resolution Unresolved
Component GHCi
Test case
Differential revisions
BlockedBy
Related
Blocking
CC Saizan
Operating system
Architecture
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information