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Index ¶
- type Path
- func (p *Path) And(path *Path) *Path
- func (p *Path) Back(tag string) *Path
- func (p *Path) Both(via ...interface{}) *Path
- func (p *Path) BothWithTags(tags []string, via ...interface{}) *Path
- func (p *Path) BuildIterator() graph.Iterator
- func (p *Path) BuildIteratorOn(qs graph.QuadStore) graph.Iterator
- func (p *Path) Clone() *Path
- func (p *Path) Count() *Path
- func (p *Path) Except(path *Path) *Path
- func (p *Path) Filter(op iterator.Operator, node quad.Value) *Path
- func (p *Path) Follow(path *Path) *Path
- func (p *Path) FollowRecursive(via interface{}, depthTags []string) *Path
- func (p *Path) FollowReverse(path *Path) *Path
- func (p *Path) Has(via interface{}, nodes ...quad.Value) *Path
- func (p *Path) HasReverse(via interface{}, nodes ...quad.Value) *Path
- func (p *Path) In(via ...interface{}) *Path
- func (p *Path) InPredicates() *Path
- func (p *Path) InWithTags(tags []string, via ...interface{}) *Path
- func (p *Path) Is(nodes ...quad.Value) *Path
- func (p *Path) IsMorphism() bool
- func (p *Path) Iterate(ctx context.Context) *graph.IterateChain
- func (p *Path) LabelContext(via ...interface{}) *Path
- func (p *Path) LabelContextWithTags(tags []string, via ...interface{}) *Path
- func (p *Path) Limit(v int64) *Path
- func (p *Path) Morphism() graph.ApplyMorphism
- func (p *Path) Or(path *Path) *Path
- func (p *Path) Out(via ...interface{}) *Path
- func (p *Path) OutPredicates() *Path
- func (p *Path) OutWithTags(tags []string, via ...interface{}) *Path
- func (p *Path) Regex(pattern *regexp.Regexp) *Path
- func (p *Path) RegexWithRefs(pattern *regexp.Regexp) *Path
- func (p *Path) Reverse() *Path
- func (p *Path) Save(via interface{}, tag string) *Path
- func (p *Path) SaveOptional(via interface{}, tag string) *Path
- func (p *Path) SaveOptionalReverse(via interface{}, tag string) *Path
- func (p *Path) SaveReverse(via interface{}, tag string) *Path
- func (p *Path) Skip(v int64) *Path
- func (p *Path) Tag(tags ...string) *Path
- func (p *Path) Unique() *Path
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type Path ¶
type Path struct {
// contains filtered or unexported fields
}
Path represents either a morphism (a pre-defined path stored for later use), or a concrete path, consisting of a morphism and an underlying QuadStore.
func StartMorphism ¶
StartMorphism creates a new Path with no underlying QuadStore.
func StartPathNodes ¶ added in v0.6.1
StartPathNodes creates a new Path from a set of nodes and an underlying QuadStore.
func (*Path) And ¶
And updates the current Path to represent the nodes that match both the current Path so far, and the given Path.
func (*Path) Back ¶
Back returns to a previously tagged place in the path. Any constraints applied after the Tag will remain in effect, but traversal continues from the tagged point instead, not from the end of the chain.
For example:
// Will return "bob" iff "bob" is cool
StartPath(qs, "bob").Tag("person_tag").Out("status").Is("cool").Back("person_tag")
func (*Path) Both ¶
Both updates this path following both inbound and outbound predicates.
For example:
// Return the list of nodes that follow or are followed by "B".
//
// Will return []string{"A", "C", "D", "F} if there are the appropriate
// edges from those nodes to "B" labelled "follows", in either direction.
StartPath(qs, "B").Both("follows")
func (*Path) BothWithTags ¶ added in v0.6.1
BothWithTags is exactly like Both, except it tags the value of the predicate traversed with the tags provided.
func (*Path) BuildIterator ¶
BuildIterator returns an iterator from this given Path. Note that you must call this with a full path (not a morphism), since a morphism does not have the ability to fetch the underlying quads. This function will panic if called with a morphism (i.e. if p.IsMorphism() is true).
func (*Path) BuildIteratorOn ¶
BuildIteratorOn will return an iterator for this path on the given QuadStore.
func (*Path) Except ¶
Except updates the current Path to represent the all of the current nodes except those in the supplied Path.
For example:
// Will return []string{"B"}
StartPath(qs, "A", "B").Except(StartPath(qs, "A"))
func (*Path) Filter ¶ added in v0.6.0
Filter represents the nodes that are passing comparison with provided value.
func (*Path) Follow ¶
Follow allows you to stitch two paths together. The resulting path will start from where the first path left off and continue iterating down the path given.
func (*Path) FollowRecursive ¶ added in v0.6.1
FollowRecursive will repeatedly follow the given string predicate or Path object starting from the given node(s), through the morphism or pattern provided, ignoring loops. For example, this turns "parent" into "all ancestors", by repeatedly following the "parent" connection on the result of the parent nodes.
The second argument, "depthTags" is a set of tags that will return strings of numeric values relating to how many applications of the path were applied the first time the result node was seen.
This is a very expensive operation in practice. Be sure to use it wisely.
func (*Path) FollowReverse ¶
FollowReverse is the same as follow, except it will iterate backwards up the path given as argument.
func (*Path) Has ¶
Has limits the paths to be ones where the current nodes have some linkage to some known node.
func (*Path) HasReverse ¶ added in v0.6.0
HasReverse limits the paths to be ones where some known node have some linkage to the current nodes.
func (*Path) In ¶
In updates this Path to represent the nodes that are adjacent to the current nodes, via the given inbound predicate.
For example:
// Return the list of nodes that follow "B".
//
// Will return []string{"A", "C", "D"} if there are the appropriate
// edges from those nodes to "B" labelled "follows".
StartPath(qs, "B").In("follows")
func (*Path) InPredicates ¶
InPredicates updates this path to represent the nodes of the valid inbound predicates from the current nodes.
For example:
// Returns a list of predicates valid from "bob"
//
// Will return []string{"follows"} if there are any things that "follow" Bob
StartPath(qs, "bob").InPredicates()
func (*Path) InWithTags ¶
InWithTags is exactly like In, except it tags the value of the predicate traversed with the tags provided.
func (*Path) Is ¶
Is declares that the current nodes in this path are only the nodes passed as arguments.
func (*Path) IsMorphism ¶
IsMorphism returns whether this Path is a morphism.
func (*Path) Iterate ¶ added in v0.6.0
func (p *Path) Iterate(ctx context.Context) *graph.IterateChain
Iterate is an shortcut for graph.Iterate.
func (*Path) LabelContext ¶
LabelContext restricts the following operations (such as In, Out) to only traverse edges that match the given set of labels.
func (*Path) LabelContextWithTags ¶
LabelContextWithTags is exactly like LabelContext, except it tags the value of the label used in the traversal with the tags provided.
func (*Path) Morphism ¶
func (p *Path) Morphism() graph.ApplyMorphism
Morphism returns the morphism of this path. The returned value is a function that, when given a QuadStore and an existing Iterator, will return a new Iterator that yields the subset of values from the existing iterator matched by the current Path.
func (*Path) Or ¶
Or updates the current Path to represent the nodes that match either the current Path so far, or the given Path.
func (*Path) Out ¶
Out updates this Path to represent the nodes that are adjacent to the current nodes, via the given outbound predicate.
For example:
// Returns the list of nodes that "B" follows.
//
// Will return []string{"F"} if there is a predicate (edge) from "B"
// to "F" labelled "follows".
StartPath(qs, "A").Out("follows")
func (*Path) OutPredicates ¶
OutPredicates updates this path to represent the nodes of the valid inbound predicates from the current nodes.
For example:
// Returns a list of predicates valid from "bob"
//
// Will return []string{"follows", "status"} if there are edges from "bob"
// labelled "follows", and edges from "bob" that describe his "status".
StartPath(qs, "bob").OutPredicates()
func (*Path) OutWithTags ¶
OutWithTags is exactly like In, except it tags the value of the predicate traversed with the tags provided.
func (*Path) Regex ¶ added in v0.6.0
Regex represents the nodes that are matching provided regexp pattern. It will only include Raw and String values.
func (*Path) RegexWithRefs ¶ added in v0.6.0
RegexWithRefs is the same as Regex, but also matches IRIs and BNodes.
Consider using it carefully. In most cases it's better to reconsider your graph structure instead of relying on slow unoptimizable regexp.
An example of incorrect usage is to match IRIs:
<http://example.org/page> <http://example.org/page/foo>
Via regexp like:
http://example.org/page.*
The right way is to explicitly link graph nodes and query them by this relation:
<http://example.org/page/foo> <type> <http://example.org/page>
func (*Path) Save ¶
Save will, from the current nodes in the path, retrieve the node one linkage away (given by either a path or a predicate), add the given tag, and propagate that to the result set.
For example:
// Will return []map[string]string{{"social_status: "cool"}}
StartPath(qs, "B").Save("status", "social_status"
func (*Path) SaveOptional ¶
SaveOptional is the same as Save, but does not require linkage to exist.
func (*Path) SaveOptionalReverse ¶
SaveOptionalReverse is the same as SaveReverse, but does not require linkage to exist.
func (*Path) SaveReverse ¶
SaveReverse is the same as Save, only in the reverse direction (the subject of the linkage should be tagged, instead of the object).
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