On Sat, Sep 15, 2007 at 08:35:02PM -0700, Ryan Ingram wrote:
Prelude> let inf = repeat 1 Prelude> inf [1,1,(lots of output until I press ctrl-c),Interrupted. (I expect this to happen) Prelude> let x = inf (no output here!) Prelude> :t x x :: [Integer] Prelude> return inf [1,1,(lots of output until I press ctrl-c),Interrupted. (I also expect this to happen) Prelude> y <- return inf [1,1,(lots of output until I press ctrl-c),Interrupted. (I do not expect this to happen here!) Prelude> :t y
<interactive>:1:0: Not in scope: 'y'
Is this a bug? Why does "y <- return exp" have different behavior than "let y = exp"? Is there a way to make GHCi not print the result of an action but still make my variables get bound?
GHC manual, Flag reference, Interactive-mode options: | -fno-print-bind-result │ Turn off printing of binding results in GHCi │ dynamic │ - │ with a link to: http://haskell.org/ghc/dist/current/docs/users_guide/interactive-evaluation.... "Note that let bindings do not automatically print the value bound, unlike monadic bindings." "The automatic printing of binding results can be supressed with :set -fno-print-bind-result (this does not supress printing the result of non-binding statements). You might want to do this to prevent the result of binding statements from being fully evaluated by the act of printing them, for example." Stefan