<astar> ( neighbors cost heuristic -- astar )
Path finding using the A* algorithm

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<bfs> ( neighbors -- astar )

Vocabulary
path-finding

Inputs

neighbors	a quotation with stack effect ( node -- seq )
cost	a quotation with stack effect ( from to -- cost )
heuristic	a quotation with stack effect ( pos target -- cost )

Outputs

astar

an astar

Word description
Build an astar object from the given quotations. The neighbors one builds the list of neighbors. The cost and heuristic ones represent respectively the cost for transitioning from a node to one of its neighbor, and the underestimated cost for going from a node to the target. This solution may not be as efficient as subclassing the astar tuple.

See also
<bfs>, <dijkstra>

Definition

USING: accessors kernel path-finding.private ;

IN: path-finding

: <astar> ( neighbors cost heuristic -- astar )
    astar-simple new swap >>heuristic swap >>cost
    swap >>neighbors ;