func buildIteratorFromValue(val otto.Value, ts graph.TripleStore) graph.Iterator {
if val.IsNull() || val.IsUndefined() {
return ts.GetNodesAllIterator()
}
if val.IsPrimitive() {
thing, _ := val.Export()
switch v := thing.(type) {
case string:
it := ts.MakeFixed()
it.AddValue(ts.GetIdFor(v))
return it
default:
glog.Errorln("Trying to build unknown primitive value.")
}
}
switch val.Class() {
case "Object":
return buildIteratorTree(val.Object(), ts)
case "Array":
// Had better be an array of strings
strings := makeListOfStringsFromArrayValue(val.Object())
it := ts.MakeFixed()
for _, x := range strings {
it.AddValue(ts.GetIdFor(x))
}
return it
case "Number":
fallthrough
case "Boolean":
fallthrough
case "Date":
fallthrough
case "String":
it := ts.MakeFixed()
str, _ := val.ToString()
it.AddValue(ts.GetIdFor(str))
return it
default:
glog.Errorln("Trying to handle unsupported Javascript value.")
return graph.NewNullIterator()
}
}
func buildInOutIterator(obj *otto.Object, ts graph.TripleStore, base graph.Iterator, isReverse bool) graph.Iterator {
argList, _ := obj.Get("_gremlin_values")
if argList.Class() != "GoArray" {
glog.Errorln("How is arglist not an array? Return nothing.", argList.Class())
return graph.NewNullIterator()
}
argArray := argList.Object()
lengthVal, _ := argArray.Get("length")
length, _ := lengthVal.ToInteger()
var predicateNodeIterator graph.Iterator
if length == 0 {
predicateNodeIterator = ts.GetNodesAllIterator()
} else {
zero, _ := argArray.Get("0")
predicateNodeIterator = buildIteratorFromValue(zero, ts)
}
if length >= 2 {
var tags []string
one, _ := argArray.Get("1")
if one.IsString() {
s, _ := one.ToString()
tags = append(tags, s)
} else if one.Class() == "Array" {
tags = makeListOfStringsFromArrayValue(one.Object())
}
for _, tag := range tags {
predicateNodeIterator.AddTag(tag)
}
}
in, out := "s", "o"
if isReverse {
in, out = out, in
}
lto := graph.NewLinksToIterator(ts, base, in)
and := graph.NewAndIterator()
and.AddSubIterator(graph.NewLinksToIterator(ts, predicateNodeIterator, "p"))
and.AddSubIterator(lto)
return graph.NewHasaIterator(ts, and, out)
}
func buildIteratorTree(obj *otto.Object, ts graph.TripleStore) graph.Iterator {
if !isVertexChain(obj) {
return graph.NewNullIterator()
}
return buildIteratorTreeHelper(obj, ts, graph.NewNullIterator())
}
func buildIteratorTreeHelper(obj *otto.Object, ts graph.TripleStore, base graph.Iterator) graph.Iterator {
var it graph.Iterator
it = base
// TODO: Better error handling
kindVal, _ := obj.Get("_gremlin_type")
stringArgs := getStringArgs(obj)
var subIt graph.Iterator
prevVal, _ := obj.Get("_gremlin_prev")
if !prevVal.IsObject() {
subIt = base
} else {
subIt = buildIteratorTreeHelper(prevVal.Object(), ts, base)
}
kind, _ := kindVal.ToString()
switch kind {
case "vertex":
if len(stringArgs) == 0 {
it = ts.GetNodesAllIterator()
} else {
fixed := ts.MakeFixed()
for _, name := range stringArgs {
fixed.AddValue(ts.GetIdFor(name))
}
it = fixed
}
case "tag":
it = subIt
for _, tag := range stringArgs {
it.AddTag(tag)
}
case "save":
all := ts.GetNodesAllIterator()
if len(stringArgs) > 2 || len(stringArgs) == 0 {
return graph.NewNullIterator()
}
if len(stringArgs) == 2 {
all.AddTag(stringArgs[1])
} else {
all.AddTag(stringArgs[0])
}
predFixed := ts.MakeFixed()
predFixed.AddValue(ts.GetIdFor(stringArgs[0]))
subAnd := graph.NewAndIterator()
subAnd.AddSubIterator(graph.NewLinksToIterator(ts, predFixed, "p"))
subAnd.AddSubIterator(graph.NewLinksToIterator(ts, all, "o"))
hasa := graph.NewHasaIterator(ts, subAnd, "s")
and := graph.NewAndIterator()
and.AddSubIterator(hasa)
and.AddSubIterator(subIt)
it = and
case "saver":
all := ts.GetNodesAllIterator()
if len(stringArgs) > 2 || len(stringArgs) == 0 {
return graph.NewNullIterator()
}
if len(stringArgs) == 2 {
all.AddTag(stringArgs[1])
} else {
all.AddTag(stringArgs[0])
}
predFixed := ts.MakeFixed()
predFixed.AddValue(ts.GetIdFor(stringArgs[0]))
subAnd := graph.NewAndIterator()
subAnd.AddSubIterator(graph.NewLinksToIterator(ts, predFixed, "p"))
subAnd.AddSubIterator(graph.NewLinksToIterator(ts, all, "s"))
hasa := graph.NewHasaIterator(ts, subAnd, "o")
and := graph.NewAndIterator()
and.AddSubIterator(hasa)
and.AddSubIterator(subIt)
it = and
case "has":
fixed := ts.MakeFixed()
if len(stringArgs) < 2 {
return graph.NewNullIterator()
}
for _, name := range stringArgs[1:] {
fixed.AddValue(ts.GetIdFor(name))
}
predFixed := ts.MakeFixed()
predFixed.AddValue(ts.GetIdFor(stringArgs[0]))
subAnd := graph.NewAndIterator()
subAnd.AddSubIterator(graph.NewLinksToIterator(ts, predFixed, "p"))
subAnd.AddSubIterator(graph.NewLinksToIterator(ts, fixed, "o"))
hasa := graph.NewHasaIterator(ts, subAnd, "s")
and := graph.NewAndIterator()
and.AddSubIterator(hasa)
and.AddSubIterator(subIt)
it = and
case "morphism":
it = base
case "and":
arg, _ := obj.Get("_gremlin_values")
firstArg, _ := arg.Object().Get("0")
if !isVertexChain(firstArg.Object()) {
return graph.NewNullIterator()
}
argIt := buildIteratorTree(firstArg.Object(), ts)
and := graph.NewAndIterator()
and.AddSubIterator(subIt)
and.AddSubIterator(argIt)
it = and
case "back":
arg, _ := obj.Get("_gremlin_back_chain")
argIt := buildIteratorTree(arg.Object(), ts)
and := graph.NewAndIterator()
and.AddSubIterator(subIt)
and.AddSubIterator(argIt)
it = and
case "is":
fixed := ts.MakeFixed()
for _, name := range stringArgs {
fixed.AddValue(ts.GetIdFor(name))
}
and := graph.NewAndIterator()
and.AddSubIterator(fixed)
and.AddSubIterator(subIt)
it = and
case "or":
arg, _ := obj.Get("_gremlin_values")
firstArg, _ := arg.Object().Get("0")
if !isVertexChain(firstArg.Object()) {
return graph.NewNullIterator()
}
argIt := buildIteratorTree(firstArg.Object(), ts)
or := graph.NewOrIterator()
or.AddSubIterator(subIt)
or.AddSubIterator(argIt)
it = or
case "both":
// Hardly the most efficient pattern, but the most general.
// Worth looking into an Optimize() optimization here.
clone := subIt.Clone()
it1 := buildInOutIterator(obj, ts, subIt, false)
it2 := buildInOutIterator(obj, ts, clone, true)
or := graph.NewOrIterator()
or.AddSubIterator(it1)
or.AddSubIterator(it2)
it = or
case "out":
it = buildInOutIterator(obj, ts, subIt, false)
case "follow":
// Follow a morphism
arg, _ := obj.Get("_gremlin_values")
firstArg, _ := arg.Object().Get("0")
if isVertexChain(firstArg.Object()) {
return graph.NewNullIterator()
}
it = buildIteratorTreeHelper(firstArg.Object(), ts, subIt)
case "followr":
// Follow a morphism
arg, _ := obj.Get("_gremlin_followr")
if isVertexChain(arg.Object()) {
return graph.NewNullIterator()
}
it = buildIteratorTreeHelper(arg.Object(), ts, subIt)
case "in":
it = buildInOutIterator(obj, ts, subIt, true)
}
return it
}