graph.java

mmlang> :[model,mm]                                              // the base model (int,bool,real,str,lst,rec)
......>  [define,
......>    vertex<=rec,                                          // a vertex is a sort of record
......>    vertex<=int-<('id'->_),                               // a vertex can be constructed from an int
......>    edge<=rec,                                            // an edge is a sort of record
......>    edge<=(vertex;vertex)-<('source'->.0,'target'->.1)]   // an edge can be constructed from a vertex x vertex pair
==>_[define,vertex<=rec,vertex<=int[split,('id'->int)],edge<=rec,edge<=(vertex;vertex)[split,('source'->vertex<=(vertex;vertex)[get,0,_],'target'->vertex<=(vertex;vertex)[get,1,_])]]

mmlang> 5 => vertex                                              // morph 5 into a vertex
==>vertex:('id'->5)
mmlang> (5;6) => (vertex;vertex)                                 // morph a pair of ints into a pair of vertices
==>(vertex:('id'->5);vertex:('id'->6))
mmlang> (5;6) => (vertex;vertex) => edge                         // morph int-pair to vertex-pair to an edge
==>edge:('source'->vertex:('id'->5),'target'->vertex:('id'->6))
mmlang> (5;6) => edge                                            // morph an int-pair into an edge
==>edge:('source'->vertex:('id'->5),'target'->vertex:('id'->6))  // a search of the model's paths yield the shortest path from int-pair to edge
mmlang>