graph.js

'use strict'; import * as cypher from './cypher.js' const uniq = (value, index, self) => self.indexOf(value) === index export class Graph { constructor(nodes=[], rels=[]) { this.nodes = nodes; this.rels = rels; } addNode(type, props={}){ const obj = {type, in:[], out:[], props}; this.nodes.push(obj); return this.nodes.length-1; } addRel(type, from, to, props={}) { const obj = {type, from, to, props}; this.rels.push(obj); const rid = this.rels.length-1; this.nodes[from].out.push(rid) this.nodes[to].in.push(rid); return rid; } tally(){ const tally = list => list.reduce((s,e)=>{s[e.type] = s[e.type] ? s[e.type]+1 : 1; return s}, {}); return { nodes:tally(this.nodes), rels:tally(this.rels)}; } size(){ return this.nodes.length + this.rels.length; } static load(obj) { // let obj = await fetch(url).then(res => res.json()) return new Graph(obj.nodes, obj.rels) } static async fetch(url) { const obj = await fetch(url).then(res => res.json()) return Graph.load(obj) } static async read(path) { const json = await Deno.readTextFile(path); const obj = JSON.parse(json); return Graph.load(obj) } // static async import(path) { // let module = await import(path, {assert: {type: "json"}}) // return Graph.load(module.default) // } n(type=null, props={}) { let nids = Object.keys(this.nodes).map(key => +key) if (type) nids = nids.filter(nid => this.nodes[nid].type == type) for (const key in props) nids = nids.filter(nid => this.nodes[nid].props[key] == props[key]) return new Nodes(this, nids) } /** * Converts a graph to a JavaScript Object Notation (JSON) string using JSON.stringify. @param - replacer A function that transforms the results. @param - space Adds indentation, white space, and line break characters to the return- * @returns {string} JSON string containing serialized graph */ stringify(...args) { const obj = { nodes: this.nodes, rels: this.rels } return JSON.stringify(obj, ...args) } search (query, opt={}) { const tree = cypher.parse(query) // console.dir(tree, {depth:15}) const code = cypher.gen(0,tree[0][0],{}) // console.log(code) cypher.check(this.tally(),code,opt.errors) return cypher.apply(this, code) } } // Fluent Interface (deprecated?) export class Nodes { constructor (graph, nids) { // console.log('Nodes',{graph:graph.size(),type,nids}) this.graph = graph this.nids = nids } // n(type=null, props={}) { // // console.log('Nodes.n',{type,props}) // let nids = this.nids // if (type) nids = nids.filter(nid => this.nodes[nid].type == type) // for (let key in props) nids = nids.filter(nid => this.nodes[nid].props[key] == props[key]) // return new Nodes(this.graph, type, nids) // } i(type=null, props={}) { // console.log('Nodes.i',{type,props}) let rids = this.nids.map(nid => this.graph.nodes[nid].in).flat().filter(uniq) if (type) rids = rids.filter(rid => this.graph.rels[rid].type == type) for (const key in props) rids = rids.filter(rid => this.graph.rels[rid].props[key] == props[key]) return new Rels(this.graph, rids) } o(type=null, props={}) { // console.log('Nodes.o',{type,props}) let rids = this.nids.map(nid => this.graph.nodes[nid].out).flat().filter(uniq) if (type) rids = rids.filter(rid => this.graph.rels[rid].type == type) for (const key in props) rids = rids.filter(rid => this.graph.rels[rid].props[key] == props[key]) return new Rels(this.graph, rids) } props(key='name') { // console.log('Nodes.p',{key}) return this.nids.map(nid => this.graph.nodes[nid].props[key]).filter(uniq).sort() } types() { return this.nids.map(nid => this.graph.nodes[nid].type).filter(uniq).sort() } tally(){ const tally = list => list.reduce((s,e)=>{s[e.type] = s[e.type] ? s[e.type]+1 : 1; return s}, {}); return { nodes:tally(this.nids.map(nid => this.graph.nodes[nid]))}; } size(){ return this.nids.length } filter(f) { const nodes = this.graph.nodes const nids = this.nids.filter(nid => { const node = nodes[nid] return f(node.type,node.props) }) return new Nodes(this.graph,nids) } map(f) { const nodes = this.graph.nodes const result = this.nids.map(nid => { const node = nodes[nid] return f(node) }) return result } } export class Rels { constructor (graph, rids) { // console.log('Rels',{graph:graph.size(),type,rids}) this.graph = graph this.rids = rids } f(type=null, props={}) { // console.log('Rels.f',{type,props}) let nids = this.rids.map(rid => this.graph.rels[rid].from).filter(uniq) if (type) nids = nids.filter(nid => this.graph.nodes[nid].type == type) for (const key in props) nids = nids.filter(nid => this.graph.nodes[nid].props[key] == props[key]) return new Nodes(this.graph, nids) } t(type=null, props={}) { // console.log('Rels.t',{type,props}) let nids = this.rids.map(rid => this.graph.rels[rid].to).filter(uniq) if (type) nids = nids.filter(nid => this.graph.nodes[nid].type == type) for (const key in props) nids = nids.filter(nid => this.graph.nodes[nid].props[key] == props[key]) return new Nodes(this.graph, nids) } props(key='name') { // console.log('Rels.p',{key}) return this.rids.map(rid => this.graph.rels[rid].props[key]).filter(uniq).sort() } types() { return this.rids.map(rid => this.graph.rels[rid].type).filter(uniq).sort() } tally(){ const tally = list => list.reduce((s,e)=>{s[e.type] = s[e.type] ? s[e.type]+1 : 1; return s}, {}); return { rels:tally(this.rids.map(nid => this.graph.rels[nid]))}; } size(){ return this.rids.length } filter(f) { const rels = this.graph.rels const rids = this.rids.filter(rid => { const rel = rels[rid] return f(rel.type,rel.props) }) return new Rels(this.graph,rids) } map(f) { const rels = this.graph.rels const result = this.rids.map(rid => { const rel = rels[rid] return f(rel) }) return result } }