This is a very small (120 sloc) single file, single function A* implementation in Go.
I implemented it to use in games with tile-based maps. It's not trying to be super-generic or super-flexible. It's just small and straightforward.
The only function is FindPath and the only data structure is Point.
typePointstruct {
X, Yint
}
funcFindPath(grid [][]byte, start, endPoint) []Point