Safe Haskell | None |
---|
Rewrite rules are represented as nested monads: a Rule
is a Pattern
that returns a Rewrite
the latter directly defining the transformation of the graph.
For rule construction a few functions a provided: The most basic one is rewrite
. But in most cases erase
, rewire
, and 'replace*' should be more convenient. These functions express rewrites that replace the matched nodes of the Pattern
, which comes quite close to the L -> R
form in which graph rewriting rules are usually expressed.
- data Replace n a
- type Rule n = Pattern n (Rewrite n ())
- apply :: Rule n -> Rewrite n ()
- rewrite :: (Match -> Rewrite n a) -> Rule n
- erase :: View [Port] n => Rule n
- rewire :: View [Port] n => [[Edge]] -> Rule n
- replace :: View [Port] n => Replace n () -> Rule n
- byNode :: (View [Port] n, View v n) => v -> Replace n ()
- byNewNode :: View [Port] n => n -> Replace n ()
- byEdge :: Replace n Edge
- byWire :: Edge -> Edge -> Replace n ()
- byConnector :: [Edge] -> Replace n ()
- (>>>) :: Rule n -> Rule n -> Rule n
- exhaustive :: Rule n -> Rule n
- everywhere :: Rule n -> Rule n
Documentation
rewrite :: (Match -> Rewrite n a) -> Rule nSource
primitive rule construction with the matched nodes of the left hand side as a parameter
erase :: View [Port] n => Rule nSource
constructs a rule that deletes all of the matched nodes from the graph
rewire :: View [Port] n => [[Edge]] -> Rule nSource
Constructs a rule from a list of rewirings. Each rewiring specifies a list of hyperedges that are to be merged into a single hyperedge. All matched nodes of the left-hand side are removed.
byConnector :: [Edge] -> Replace n ()Source
(>>>) :: Rule n -> Rule n -> Rule nSource
Apply two rules consecutively. Second rule is only applied if first one succeeds. Fails if (and only if) first rule fails.
exhaustive :: Rule n -> Rule nSource
Make a rule exhaustive, i.e. such that (when applied) it reduces redexes until no redexes are occur in the graph.
everywhere :: Rule n -> Rule nSource
Make a rule parallel, i.e. such that (when applied) all current redexes are contracted one by one. Neither new redexes or destroyed redexes are reduced.