Mercurial > feed
changeset 14:f641cfcd5153
Add gather pattern.
| author | Karn Kallio <kkallio@eka> |
|---|---|
| date | Mon, 25 Jul 2011 20:55:09 -0430 |
| parents | 7eea7ff1904c |
| children | 0140b1662994 |
| files | src/ur/feed.ur src/ur/feed.urs |
| diffstat | 2 files changed, 57 insertions(+), 0 deletions(-) [+] |
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--- a/src/ur/feed.ur Sun Jul 24 03:36:07 2011 -0430 +++ b/src/ur/feed.ur Mon Jul 25 20:55:09 2011 -0430 @@ -242,6 +242,55 @@ None => None | Some (cdata, _) => Some ((pdata, cdata), True)} +con gatherInternal (parent :: Type) (child :: Type) (data :: Type) = option (parent * bool * int * option child * list data) + +fun gather [parentI ::: Type] [parent ::: Type] [childI ::: Type] [child ::: Type] + (parent : pattern parentI parent) (child : pattern childI child) + : pattern (gatherInternal parentI childI child) (parent * list child) = + {Initial = None, + EnterTag = fn tinfo state => + case state of + None => + (case parent.EnterTag tinfo parent.Initial of + None => None + | Some pstate => Some (Some (pstate, False, 1, None, Nil))) + | Some (pstate, return, depth, cstate, clist) => + let + val cstate' = child.EnterTag tinfo (Option.get child.Initial cstate) + in + case child.Finished (Option.get child.Initial cstate') of + None => + Some (Some (pstate, return, depth+1, cstate', clist)) + | Some (cdata, _) => + Some (Some (pstate, return, depth+1, None, cdata :: clist)) + end, + ExitTag = fn state => + case state of + None => None + | Some (pstate, _, 1, cstate, clist) => + Some (Some (pstate, True, 1, cstate, clist)) + | Some (pstate, return, depth, cstate, clist) => + let + val cstate' = child.ExitTag (Option.get child.Initial cstate) + in + case child.Finished (Option.get child.Initial cstate') of + None => + Some (Some (pstate, return, depth-1, cstate', clist)) + | Some (cdata, _) => + Some (Some (pstate, return, depth-1, None, cdata :: clist)) + end, + Finished = fn state => + case state of + None => None + | Some (pstate, return, _, _, clist) => + case parent.Finished pstate of + None => None + | Some (pdata, _) => + if return then + Some ((pdata, List.rev clist), False) + else + None} + type document = string val show_document = _
--- a/src/ur/feed.urs Sun Jul 24 03:36:07 2011 -0430 +++ b/src/ur/feed.urs Mon Jul 25 20:55:09 2011 -0430 @@ -71,6 +71,14 @@ * be matched at any depth within the parent's subtree. Unlike [children], * [tree] finds as many subtree matches per parent node as possible. *) +con gatherInternal :: Type -> Type -> Type -> Type + +val gather : parentI ::: Type -> parent ::: Type -> childI ::: Type -> child ::: Type + -> pattern parentI parent -> pattern childI child + -> pattern (gatherInternal parentI childI child) (parent * list child) +(* A combinator like tree that collects matching subtree patterns into a list rather + * than handling them one at a time. *) + type document val show_document : show document (* Type of uninterpreted XML documents *)