Rijk-Jan van Haaften writes:

I used 3 main properties for the process: ... 2. Lifting local let definitions to a higher level let f = let g = gExpr in fExpr in expr

can be translated into let g = gExpr f = fExpr in expr

The definition of g which is local for f in the first expression is made more global in the second one.

Care has to be taken if g (which might be bound outside this let-block) occurs in expr, because with the translated version it is now bound to gExpr. Renaming helps (for some unused g'):

let g' = gExpr f = fExpr[g <- g'] in expr

-- Janis Voigtlaender http://wwwtcs.inf.tu-dresden.de/~voigt/ mailto:voigt@tcs.inf.tu-dresden.de