[/] [trunk/] [src/] [lib/] [symbol.sml] - Blame information for rev 7

Line No. Rev Author Line
1 4 tbourke 
(* $Id: symbol.sml 7 2007-10-31 05:39:12Z tbourke $ *)
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structure Symbol : SYMBOL = struct
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  infix <+ <- ++ </ =:=
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  type symbol = Atom.atom
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  type symbolset = AtomSet.set
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  fun set <+ item = AtomSet.add (set, item)
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  fun set </ item = AtomSet.difference (set, AtomSet.singleton item)
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  fun i <- set    = AtomSet.member (set, i)
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  val op++        = AtomSet.union
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  val emptyset    = AtomSet.empty
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  fun s1 =:= s2   = Atom.compare (s1, s2) = EQUAL
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  local structure SS = Substring in
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  fun getNewName (base, names) =
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    (*{{{1*)
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    if not (AtomSet.member (names, base)) then base
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    else let
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           fun getPrefix s = SS.string (SS.dropr Char.isDigit (SS.full s))
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           fun getSuffix s = let
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               val suf = SS.taker Char.isDigit (SS.full s)
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             in
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               if SS.isEmpty suf then 0
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               else valOf (Int.fromString (SS.string suf))
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             end
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           val prefix = getPrefix (Atom.toString base)
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           fun maxSuffix (a, m) = let val s = Atom.toString a in
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               if String.isPrefix prefix s
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               then Int.max (m, getSuffix s) else m
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             end
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           val suffix = (AtomSet.foldl maxSuffix 0 names) + 1
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         in
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            Atom.atom (prefix ^ Int.toString suffix)
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         end (*}}}1*)
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  end (*local*)
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end
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