GHCi: Pressing Tab after `:break ` produces a lot of nonsense.
Summary
In GHCi, typing :break<blank><Tab>
shows a lot of values that are not eligible for breakpoints .
Steps to reproduce
- Start GHCi.
- Load a simple Main.hs file.
- Type
:break
(Note the blank after:break
!). - Press the
Tab
key.
The generated output:
roland@goms:~/Projekte/ghctest$ ghci Main.hs
GHCi, version 8.8.1: https://www.haskell.org/ghc/ :? for help
[1 of 1] Compiling Main ( Main.hs, interpreted )
Ok, one module loaded.
*Main> :break
Display all 513 possibilities? (y or n)
!! Prelude.Traversable Prelude.repeat fromRational
$ Prelude.True Prelude.replicate fst
$! Prelude.Word Prelude.return gcd
&& Prelude.^ Prelude.reverse getChar
* Prelude.^^ Prelude.round getContents
** Prelude.abs Prelude.scaleFloat getLine
<many many more lines>
However, using these values for breakpoints produces error messages:
*Main> :break Prelude.repeat
cannot set breakpoint on repeat: module GHC.List is not interpreted
*Main> :break fromRational
cannot set breakpoint on fromRational: module GHC.Real is not interpreted
Expected behavior
Show only values eligible for breakpoints.
Environment
- GHC version used: 7.10.3 - 8.8.1