Single-Stepping evaluation in GHCi

The goal is to have, in GHCi, the interim results provided by the function before the end result by a command available from the prompt, like this: for example:[[BR]]

Prelude> g op n [] = n ; g op n (h:t) = h op g op n t[[BR]]

Prelude> :stp[[BR]]

Prelude> g (*) 2 [1..3][[BR]]

1* (*) 2 [2,3][[BR]]

1*2 (*) 2 [3][[BR]]

1*2*3 (*) 2 [][[BR]]

1*2*3*2[[BR]]

12[[BR]]

Prelude>[[BR]]

And to quit the mode we write from the prompt a command like this[[BR]]

Prelude> :quitstp

Trac metadata

Trac field	Value
Version	8.0.1
Type	FeatureRequest
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	GHCi
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