returns a graph formatter procedure of the specified types; the following formats are supported:
'dot dot format (see the GraphViz documentation) 'vcg vcg format (see the VCG documetation)
Each graph formatter procedure is of the form LAMBDA OUT-PORT GRAPH [OPTION-LIST], where
- OUT-PORT is the port to which the graph representation should be output
- GRAPH is a graph object that follows the API defined by the e.g. digraph module
- OPTION-LIST is a list of options of the form STMT NAME VAL, in the case of the dot formatter, or NAME VAL, in the case of the dot and vcg formatters. Each of the options will be included in the beginning of the graph definition output.