Celestin Apprentice 7/Apprentice-Release7.iso/Source Code/C/Applications/Moscow ML 1.42/examples/manual/Reduce.sml

Text File | 1997-08-18 | 367 b | 12 lines | [TEXT/R*ch]

local open Expr
in
    fun negate (Neg e) = e
      | negate e       = Neg e
    fun reduce (Neg (Neg e))      = e
      | reduce (Neg e)            = negate (reduce e)
      | reduce (Plus (Cst 0, e2)) = reduce e2
      | reduce (Plus (e1, Cst 0)) = reduce e1
      | reduce (Plus (e1, e2))    = Plus (reduce e1, reduce e2)
      | reduce e                  = e
end