Editing Speculative execution (section)

===Lazy execution===
{{Main|Lazy evaluation}}

Lazy execution is the opposite of eager execution, and does not involve speculation. The incorporation of speculative execution into implementations of the [[Haskell (programming language)|Haskell programming language]], a lazy language, is a current research topic. [[Eager Haskell]], a variant of the language, is designed around the idea of speculative execution. A 2003 PhD thesis made [[Glasgow Haskell Compiler|GHC]] support a kind of speculative execution with an abortion mechanism to back out in case of a bad choice called ''optimistic execution''.<ref name="Robert Ennals and Simon Peyton Jones">{{cite journal|url=https://www.microsoft.com/en-us/research/publication/optimistic-evaluation-fast-evaluation-strategy-non-strict-programs/|title=Optimistic Evaluation: a fast evaluation strategy for non-strict programs|first1=Simon Peyton|last1=Jones|first2=Robert|last2=Ennals|date=1 August 2003|access-date=15 May 2019|via=www.microsoft.com}}</ref> It was deemed too complicated.<ref>{{cite web | url=https://mail.haskell.org/pipermail/haskell/2006-August/018424.html | title=&#91;Haskell&#93; Optimistic Evaluation? | date=31 August 2006 }}</ref>