With a `type` that depends on two generic typevars, the type inference
implementation seems to get stuck on a particular binding of the second typevar
based on the first... is that expected?
Specifically, for these two sections:
var w = DGraph[int,int]()
let _ = w.add_edges(@[(0, 1, 10), (0, 4, 3), (1, 2, 2), (1, 4, 4)])
Run
var g = DGraph[int,float]()
let _ = g.add_edges(@[(3,4,3.5),(4,5,4.5)])
Run
the second one fails with `Error: type mismatch: got <DNode[system.int,
system.float]> but expected 'DNode[system.int, system.int]'`
If I reverse the sections, I get a similar failure with the `got` and
`expected` types switched.
However, these work fine following either of the above:
var h = DGraph[uint,float]()
let _ = h.add_edges(@[(3u,4u,3.5),(4u,5u,4.5)])
Run
var k = DGraph[char,int]()
let _ = k.add_edges(@[('s','a',3),('s','c',2),('s','f',6)])
Run
The only thing that distinguishes the failure seems to the type taken on by the
first typevar.
Help!?
Thanks.
\-- e
Below are more details:
type
DEdge*[K, V] = ref object
fm*: DNode[K]
to*: DNode[K]
weight*: V
DNode*[K, V] = ref object
key*: K
outedges: HashSet[DEdge[K, V]]
inedges: HashSet[DEdge[K, V]]
priority*: V # for algorithms to sort upon
index*: int # for algorithms to store sort position
DGraph*[K, V] = object
# A directed graph of nodes and directed edges
nodes: Table[K, DNode[K, V]]
Run
and
proc add_edges*[K, V](graph: var DGraph[K, V], edges: seq[(K,K,V,)]):
seq[DEdge[K, V]] =
for (n1, n2, w) in edges:
result.add(add_edge(graph, n1, n2, w))
proc add_edge*[K, V](graph: var DGraph[K, V], fm: K, to: K, weight: V = 1):
DEdge[K, V] =
var n1 = graph.add_node(fm)
var n2 = graph.add_node(to)
result = DEdge[K, V](fm: n1, to: n2, weight: weight)
result.fm.outedges.incl(result)
result.to.inedges.incl(result)
proc add_node*[K, V](graph: var DGraph[K, V], key: K): DNode[K, V] =
Run
