Add Save/SaveReverse and HAS API and split path.go into two files

This commit is contained in:
Barak Michener 2015-06-02 15:27:12 -04:00
parent 34de880945
commit f825fef208
3 changed files with 316 additions and 165 deletions

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@ -0,0 +1,262 @@
// Copyright 2014 The Cayley Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package path
import (
"github.com/google/cayley/graph"
"github.com/google/cayley/graph/iterator"
"github.com/google/cayley/quad"
)
func isMorphism(nodes ...string) morphism {
return morphism{
Name: "is",
Reversal: func() morphism { return isMorphism(nodes...) },
Apply: func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
var sub graph.Iterator
if len(nodes) == 0 {
sub = qs.NodesAllIterator()
} else {
fixed := qs.FixedIterator()
for _, n := range nodes {
fixed.Add(qs.ValueOf(n))
}
sub = fixed
}
and := iterator.NewAnd(qs)
and.AddSubIterator(sub)
and.AddSubIterator(it)
return and
},
}
}
func hasMorphism(via interface{}, nodes ...string) morphism {
return morphism{
Name: "has",
Reversal: func() morphism { return hasMorphism(via, nodes...) },
Apply: func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
var sub graph.Iterator
if len(nodes) == 0 {
sub = qs.NodesAllIterator()
} else {
fixed := qs.FixedIterator()
for _, n := range nodes {
fixed.Add(qs.ValueOf(n))
}
sub = fixed
}
var viaPath *Path
if via != nil {
viaPath = buildViaPath(qs, via)
} else {
viaPath = buildViaPath(qs)
}
subAnd := iterator.NewAnd(qs)
subAnd.AddSubIterator(iterator.NewLinksTo(qs, sub, quad.Object))
subAnd.AddSubIterator(iterator.NewLinksTo(qs, viaPath.BuildIterator(), quad.Predicate))
hasa := iterator.NewHasA(qs, subAnd, quad.Subject)
and := iterator.NewAnd(qs)
and.AddSubIterator(it)
and.AddSubIterator(hasa)
return and
},
}
}
func tagMorphism(tags ...string) morphism {
return morphism{
Name: "tag",
Reversal: func() morphism { return tagMorphism(tags...) },
Apply: func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
for _, t := range tags {
it.Tagger().Add(t)
}
return it
},
tags: tags,
}
}
func outMorphism(via ...interface{}) morphism {
return morphism{
Name: "out",
Reversal: func() morphism { return inMorphism(via...) },
Apply: func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
path := buildViaPath(qs, via...)
return inOutIterator(path, it, false)
},
}
}
func inMorphism(via ...interface{}) morphism {
return morphism{
Name: "in",
Reversal: func() morphism { return outMorphism(via...) },
Apply: func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
path := buildViaPath(qs, via...)
return inOutIterator(path, it, true)
},
}
}
func iteratorMorphism(it graph.Iterator) morphism {
return morphism{
Name: "iterator",
Reversal: func() morphism { return iteratorMorphism(it) },
Apply: func(qs graph.QuadStore, subIt graph.Iterator) graph.Iterator {
and := iterator.NewAnd(qs)
and.AddSubIterator(it)
and.AddSubIterator(subIt)
return and
},
}
}
func andMorphism(p *Path) morphism {
return morphism{
Name: "and",
Reversal: func() morphism { return andMorphism(p) },
Apply: func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
subIt := p.BuildIteratorOn(qs)
and := iterator.NewAnd(qs)
and.AddSubIterator(it)
and.AddSubIterator(subIt)
return and
},
}
}
func orMorphism(p *Path) morphism {
return morphism{
Name: "or",
Reversal: func() morphism { return orMorphism(p) },
Apply: func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
subIt := p.BuildIteratorOn(qs)
and := iterator.NewOr()
and.AddSubIterator(it)
and.AddSubIterator(subIt)
return and
},
}
}
func followMorphism(p *Path) morphism {
return morphism{
Name: "follow",
Reversal: func() morphism { return followMorphism(p.Reverse()) },
Apply: func(qs graph.QuadStore, base graph.Iterator) graph.Iterator {
return p.Morphism()(qs, base)
},
}
}
func exceptMorphism(p *Path) morphism {
return morphism{
Name: "except",
Reversal: func() morphism { return exceptMorphism(p) },
Apply: func(qs graph.QuadStore, base graph.Iterator) graph.Iterator {
subIt := p.BuildIteratorOn(qs)
notIt := iterator.NewNot(subIt, qs.NodesAllIterator())
and := iterator.NewAnd(qs)
and.AddSubIterator(base)
and.AddSubIterator(notIt)
return and
},
}
}
func saveMorphism(via interface{}, tag string) morphism {
return morphism{
Name: "save",
Reversal: func() morphism { return saveMorphism(via, tag) },
Apply: func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
return buildSave(qs, via, tag, it, false)
},
tags: []string{tag},
}
}
func saveReverseMorphism(via interface{}, tag string) morphism {
return morphism{
Name: "saver",
Reversal: func() morphism { return saveReverseMorphism(via, tag) },
Apply: func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
return buildSave(qs, via, tag, it, true)
},
tags: []string{tag},
}
}
func buildSave(qs graph.QuadStore, via interface{}, tag string, it graph.Iterator, reverse bool) graph.Iterator {
all := qs.NodesAllIterator()
all.Tagger().Add(tag)
node, allDir := quad.Subject, quad.Object
var viaPath *Path
if via != nil {
viaPath = buildViaPath(qs, via)
} else {
viaPath = buildViaPath(qs)
}
if reverse {
node, allDir = allDir, node
}
lto := iterator.NewLinksTo(qs, all, allDir)
subAnd := iterator.NewAnd(qs)
subAnd.AddSubIterator(iterator.NewLinksTo(qs, viaPath.BuildIterator(), quad.Predicate))
subAnd.AddSubIterator(lto)
hasa := iterator.NewHasA(qs, subAnd, node)
and := iterator.NewAnd(qs)
and.AddSubIterator(hasa)
and.AddSubIterator(it)
return and
}
func inOutIterator(viaPath *Path, it graph.Iterator, reverse bool) graph.Iterator {
in, out := quad.Subject, quad.Object
if reverse {
in, out = out, in
}
lto := iterator.NewLinksTo(viaPath.qs, it, in)
and := iterator.NewAnd(viaPath.qs)
and.AddSubIterator(iterator.NewLinksTo(viaPath.qs, viaPath.BuildIterator(), quad.Predicate))
and.AddSubIterator(lto)
return iterator.NewHasA(viaPath.qs, and, out)
}
func buildViaPath(qs graph.QuadStore, via ...interface{}) *Path {
if len(via) == 0 {
return PathFromIterator(qs, qs.NodesAllIterator())
} else if len(via) == 1 {
v := via[0]
switch p := v.(type) {
case *Path:
return p
case string:
return StartPath(qs, p)
default:
panic("Invalid type passed to buildViaPath.")
}
}
var strings []string
for _, s := range via {
if str, ok := s.(string); ok {
strings = append(strings, str)
} else {
panic("Non-string type passed to long Via path")
}
}
return StartPath(qs, strings...)
}

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@ -14,16 +14,13 @@
package path
import (
"github.com/google/cayley/graph"
"github.com/google/cayley/graph/iterator"
"github.com/google/cayley/quad"
)
import "github.com/google/cayley/graph"
type morphism struct {
Name string
Reversal func() morphism
Apply graph.ApplyMorphism
tags []string
}
// Path represents either a morphism (a pre-defined path stored for later use),
@ -76,11 +73,15 @@ func (p *Path) Reverse() *Path {
return newPath
}
// Is declares that the current nodes in this path are only the nodes
// passed as arguments.
func (p *Path) Is(nodes ...string) *Path {
p.stack = append(p.stack, isMorphism(nodes...))
return p
}
// Tag adds tag strings to the nodes at this point in the path for each result
// path in the set.
func (p *Path) Tag(tags ...string) *Path {
p.stack = append(p.stack, tagMorphism(tags...))
return p
@ -149,6 +150,32 @@ func (p *Path) FollowReverse(path *Path) *Path {
return p
}
// 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 (p *Path) Save(via interface{}, tag string) *Path {
p.stack = append(p.stack, saveMorphism(via, tag))
return p
}
// SaveReverse is the same as Save, only in the reverse direction
// (the subject of the linkage should be tagged, instead of the object)
func (p *Path) SaveReverse(via interface{}, tag string) *Path {
p.stack = append(p.stack, saveReverseMorphism(via, tag))
return p
}
// Has limits the paths to be ones where the current nodes have some linkage
// to some known node.
func (p *Path) Has(via interface{}, nodes ...string) *Path {
p.stack = append(p.stack, hasMorphism(via, nodes...))
return p
}
// 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
@ -178,163 +205,3 @@ func (p *Path) Morphism() graph.ApplyMorphism {
return i
}
}
func isMorphism(nodes ...string) morphism {
return morphism{
"is",
func() morphism { return isMorphism(nodes...) },
func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
var sub graph.Iterator
if len(nodes) == 0 {
sub = qs.NodesAllIterator()
} else {
fixed := qs.FixedIterator()
for _, n := range nodes {
fixed.Add(qs.ValueOf(n))
}
sub = fixed
}
and := iterator.NewAnd(qs)
and.AddSubIterator(sub)
and.AddSubIterator(it)
return and
},
}
}
func tagMorphism(tags ...string) morphism {
return morphism{
"tag",
func() morphism { return tagMorphism(tags...) },
func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
for _, t := range tags {
it.Tagger().Add(t)
}
return it
}}
}
func outMorphism(via ...interface{}) morphism {
return morphism{
"out",
func() morphism { return inMorphism(via...) },
func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
path := buildViaPath(qs, via...)
return inOutIterator(path, it, false)
},
}
}
func inMorphism(via ...interface{}) morphism {
return morphism{
"in",
func() morphism { return outMorphism(via...) },
func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
path := buildViaPath(qs, via...)
return inOutIterator(path, it, true)
},
}
}
func iteratorMorphism(it graph.Iterator) morphism {
return morphism{
"iterator",
func() morphism { return iteratorMorphism(it) },
func(qs graph.QuadStore, subIt graph.Iterator) graph.Iterator {
and := iterator.NewAnd(qs)
and.AddSubIterator(it)
and.AddSubIterator(subIt)
return and
},
}
}
func andMorphism(p *Path) morphism {
return morphism{
"and",
func() morphism { return andMorphism(p) },
func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
subIt := p.BuildIteratorOn(qs)
and := iterator.NewAnd(qs)
and.AddSubIterator(it)
and.AddSubIterator(subIt)
return and
},
}
}
func orMorphism(p *Path) morphism {
return morphism{
"or",
func() morphism { return orMorphism(p) },
func(qs graph.QuadStore, it graph.Iterator) graph.Iterator {
subIt := p.BuildIteratorOn(qs)
and := iterator.NewOr()
and.AddSubIterator(it)
and.AddSubIterator(subIt)
return and
},
}
}
func followMorphism(p *Path) morphism {
return morphism{
"follow",
func() morphism { return followMorphism(p.Reverse()) },
func(qs graph.QuadStore, base graph.Iterator) graph.Iterator {
return p.Morphism()(qs, base)
},
}
}
func exceptMorphism(p *Path) morphism {
return morphism{
"except",
func() morphism { return exceptMorphism(p) },
func(qs graph.QuadStore, base graph.Iterator) graph.Iterator {
subIt := p.BuildIteratorOn(qs)
notIt := iterator.NewNot(subIt, qs.NodesAllIterator())
and := iterator.NewAnd(qs)
and.AddSubIterator(base)
and.AddSubIterator(notIt)
return and
},
}
}
func inOutIterator(viaPath *Path, it graph.Iterator, reverse bool) graph.Iterator {
in, out := quad.Subject, quad.Object
if reverse {
in, out = out, in
}
lto := iterator.NewLinksTo(viaPath.qs, it, in)
and := iterator.NewAnd(viaPath.qs)
and.AddSubIterator(iterator.NewLinksTo(viaPath.qs, viaPath.BuildIterator(), quad.Predicate))
and.AddSubIterator(lto)
return iterator.NewHasA(viaPath.qs, and, out)
}
func buildViaPath(qs graph.QuadStore, via ...interface{}) *Path {
if len(via) == 0 {
return PathFromIterator(qs, qs.NodesAllIterator())
} else if len(via) == 1 {
v := via[0]
switch v := v.(type) {
case *Path:
return v
case string:
return StartPath(qs, v)
default:
panic("Invalid type passed to buildViaPath.")
}
}
var strings []string
for _, s := range via {
if str, ok := s.(string); ok {
strings = append(strings, str)
} else {
panic("Non-string type passed to long Via path")
}
}
return StartPath(qs, strings...)
}

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@ -160,6 +160,28 @@ func testSet(qs graph.QuadStore) []test {
path: StartPath(qs, "A", "B", "C").Except(StartPath(qs, "B")).Except(StartPath(qs, "A")),
expect: []string{"C"},
},
{
message: "show a simple save",
path: StartPath(qs).Save("status", "somecool"),
tag: "somecool",
expect: []string{"cool", "cool", "cool"},
},
{
message: "show a simple saveR",
path: StartPath(qs, "cool").SaveReverse("status", "who"),
tag: "who",
expect: []string{"G", "D", "B"},
},
{
message: "show a simple Has",
path: StartPath(qs).Has("status", "cool"),
expect: []string{"G", "D", "B"},
},
{
message: "show a double Has",
path: StartPath(qs).Has("status", "cool").Has("follows", "F"),
expect: []string{"B"},
},
}
}