On Thu, 28 Jul 2011, Paul Reiners wrote:
I have a question about the following GHCi interaction:
Prelude> let x = 23
Prelude> :show bindings
x :: Integer = _
What is the meaning of the underscore in the third line? Why doesn't it say
this, instead?
x :: Integer = 23
I have never used ':show bindings' before ... in other cases like
let x='a'
and
let x=23::Int
the value of 'x' is shown. If 'x' is bound to a function, the underscore
is shown. Thus I assume, that ':show bindings' uses the underscore for
types without text representation. But it seems not to use the 'Show'
class, since in this case Integers could be shown.
The documentation does not mention the output of values, at all:
http://www.haskell.org/ghc/docs/7.0-latest/html/users_guide/ghci-commands.html
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