#13037: Single-Stepping evaluation in GHCi -------------------------------------+------------------------------------- Reporter: vanto | Owner: Type: feature request | Status: closed Priority: normal | Milestone: Component: GHCi | Version: 8.0.1 Resolution: invalid | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Iceland_jack): You can get somewhat close using libraries like [https://hackage.haskell.org/package/simple-reflect-0.3.2/docs/Debug- SimpleReflect.html simple-reflect] (or [https://hackage.haskell.org/package/ap-reflect ap-reflect]) {{{
import Debug.SimpleReflect g op n [] = n ; g op n (h:t) = h `op` g op n t g (*) 2 [1..3] :: Expr 1 * (2 * (3 * 2)) }}}
you can even `reduce` {{{
reduce (g (*) 2 [1..3]) 1 * (2 * 6) reduce (reduce (g (*) 2 [1..3])) 1 * 12 reduce (reduce (reduce (g (*) 2 [1..3]))) 12 }}}
{{{
traverse_ print $ reduction (g (*) 2 [1..3]) 1 * (2 * (3 * 2)) 1 * (2 * 6) 1 * 12 12 }}}
-- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13037#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler