├── LICENSE ├── README.md ├── TODO.md ├── demo ├── 0-multi-web.html ├── 0-single-web.html ├── 1-node.js └── 1-web.html ├── dist ├── roomdb-web.js └── roomdb-web.min.js ├── minify ├── package.json └── src ├── AbstractClient.js ├── Fact.js ├── LocalClient.js ├── RemoteClient.js ├── RoomDB.js ├── listen.js ├── parse.js ├── roomdb-node.js ├── roomdb-web.js ├── server.js └── terms.js /LICENSE: -------------------------------------------------------------------------------- 1 | MIT License 2 | 3 | Copyright (c) 2018 Alessandro Warth 4 | 5 | Permission is hereby granted, free of charge, to any person obtaining a copy 6 | of this software and associated documentation files (the "Software"), to deal 7 | in the Software without restriction, including without limitation the rights 8 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 9 | copies of the Software, and to permit persons to whom the Software is 10 | furnished to do so, subject to the following conditions: 11 | 12 | The above copyright notice and this permission notice shall be included in all 13 | copies or substantial portions of the Software. 14 | 15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 21 | SOFTWARE. 22 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # RoomDB 2 | 3 | RoomDB is a Datalog-style database inspired by the implementation of the [Dynamicland](https://dynamicland.org/) project. It enables programmers to represent facts using natural language, with a syntax adapted from my [NL-Datalog project](https://github.com/harc/nl-datalog). 4 | 5 | ## TODO 6 | 7 | * Add documentation, examples, etc. 8 | -------------------------------------------------------------------------------- /TODO.md: -------------------------------------------------------------------------------- 1 | TODO 2 | ==== 3 | 4 | * samples vs. wishes 5 | 6 | * evidence 7 | 8 | * include "world time" in samples 9 | 10 | * factor common code from LocalClient and RemoteClient into AbstractClient 11 | 12 | * be more careful with client IDs 13 | (e.g., to prevent 2 clients from having the same ID) 14 | 15 | * consider space-insensitive matching for facts 16 | (would need a canonical representation to use as keys for factMap) 17 | 18 | * think about "primary keys"? 19 | -------------------------------------------------------------------------------- /demo/0-multi-web.html: -------------------------------------------------------------------------------- 1 | 2 | 3 | 11 | 12 |

13 | 109 | 110 | 111 | -------------------------------------------------------------------------------- /demo/0-single-web.html: -------------------------------------------------------------------------------- 1 | 2 | 3 | 11 | 12 |

13 | 201 | 202 | 203 | -------------------------------------------------------------------------------- /demo/1-node.js: -------------------------------------------------------------------------------- 1 | 'use strict'; 2 | 3 | const roomdb = require('../src/roomdb-node'); 4 | 5 | const db = roomdb.create().listen(8080); 6 | const localClient = db.client('Lola'); 7 | const remoteClient = roomdb.client('localhost', 8080, 'MrRemoto'); 8 | 9 | async function main() { 10 | console.log('facts:\n' + db + '\n'); 11 | 12 | remoteClient.assert(`#obj1 is a "circle" at (300, 400)`); 13 | remoteClient.assert(`the answer is 42`); 14 | await remoteClient.flushChanges(); 15 | console.log('\nfacts:\n' + db + '\n'); 16 | 17 | for (let n = 1; n <= 10; n++) { 18 | remoteClient.assert(`_ is a number`, n); 19 | } 20 | await remoteClient.flushChanges(); 21 | console.log('\nfacts:\n' + db + '\n'); 22 | 23 | await localClient.select(`$n is a number`).do(({n}) => { 24 | if (n % 2 === 1) { 25 | localClient.retract(`_ is a number`, n); 26 | } 27 | }); 28 | localClient.flushChanges(); 29 | console.log('\nfacts:\n' + db + '\n'); 30 | 31 | await remoteClient.select(`$o is a "circle" at ($x, $y)`).do(vars => { 32 | console.log(Object.keys(vars).map(key => key + '=' + vars[key]).join(', ')); 33 | }); 34 | await remoteClient.select(`the answer is $ans`).do(vars => { 35 | console.log(Object.keys(vars).map(key => key + '=' + vars[key]).join(', ')); 36 | }); 37 | 38 | localClient.assert('blah blah blah'); 39 | await localClient.flushChanges(); 40 | await localClient.immediatelyRetractEverythingAbout('obj1'); 41 | console.log('\nfacts:\n' + db + '\n'); 42 | } 43 | 44 | main(); 45 | -------------------------------------------------------------------------------- /demo/1-web.html: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 19 | 20 | 21 | -------------------------------------------------------------------------------- /minify: -------------------------------------------------------------------------------- 1 | node_modules/uglify-es/bin/uglifyjs src/RoomDB.js src/parser.js > dist/roomdb.min.js 2 | 3 | -------------------------------------------------------------------------------- /package.json: -------------------------------------------------------------------------------- 1 | { 2 | "name": "roomdb", 3 | "version": "0.0.3", 4 | "description": "A Datalog-style database that enables programmers to represent facts in natural language.", 5 | "main": "src/roomdb-node.js", 6 | "dependencies": { 7 | "browserify": "^15.2.0", 8 | "node-fetch": "^1.7.3", 9 | "ohm-js": "^0.14.0", 10 | "restify": "^6.3.4", 11 | "restify-cors-middleware": "^1.1.0", 12 | "restify-errors": "^5.0.0", 13 | "uglify-js": "^3.17.4" 14 | }, 15 | "repository": { 16 | "type": "git", 17 | "url": "git+https://github.com/alexwarth/roomdb.git" 18 | }, 19 | "keywords": [ 20 | "datalog", 21 | "natural", 22 | "language", 23 | "dynamicland", 24 | "harc" 25 | ], 26 | "author": "Alex Warth (http://alexwarth.com)", 27 | "license": "MIT", 28 | "bugs": { 29 | "url": "https://github.com/alexwarth/roomdb/issues" 30 | }, 31 | "homepage": "https://github.com/alexwarth/roomdb#readme", 32 | "scripts": { 33 | "clean": "rm dist/*", 34 | "build-web": "node node_modules/browserify/bin/cmd.js src/roomdb-web.js -s roomdb -o dist/roomdb-web.js && node node_modules/uglify-js/bin/uglifyjs dist/roomdb-web.js > dist/roomdb-web.min.js", 35 | "server": "node src/server.js" 36 | } 37 | } 38 | -------------------------------------------------------------------------------- /src/AbstractClient.js: -------------------------------------------------------------------------------- 1 | 'use strict'; 2 | 3 | const {Term} = require('./terms'); 4 | const parse = require('./parse'); 5 | 6 | const MAX_PARSE_CACHE_SIZE = 1000; 7 | 8 | class AbstractClient { 9 | constructor(id) { 10 | this._id = id; 11 | this._parseCache = new Map(); 12 | this._asserts = []; 13 | this._retracts = []; 14 | } 15 | 16 | assert(factString, ...fillerValues) { 17 | const fact = this._toJSONFactOrPattern(factString, ...fillerValues); 18 | this._asserts.push(fact); 19 | return this; 20 | } 21 | 22 | retract(patternString, ...fillerValues) { 23 | const pattern = this._toJSONFactOrPattern(patternString, ...fillerValues); 24 | this._retracts.push(pattern); 25 | return this; 26 | } 27 | 28 | async flushChanges() { 29 | throw new Error('subclass responsibility'); 30 | } 31 | 32 | async immediatelyAssert(factString, ...fillerValues) { 33 | this.assert(factString, ...fillerValues); 34 | await this.flushChanges(); 35 | return this; 36 | } 37 | 38 | async immediatelyRetract(patternString, ...fillerValues) { 39 | this.retract(patternString, ...fillerValues); 40 | await this.flushChanges(); 41 | return this; 42 | } 43 | 44 | async immediatelyRetractEverythingAbout(name) { 45 | throw new Error('subclass responsibility'); 46 | } 47 | 48 | async immediatelyRetractEverythingAssertedByMe() { 49 | throw new Error('subclass responsibility'); 50 | } 51 | 52 | async getAllFacts() { 53 | throw new Error('subclass responsibility'); 54 | } 55 | 56 | _toJSONFactOrPattern(factOrPatternString, ...fillerValues) { 57 | if (arguments.length === 0) { 58 | throw new Error('not enough arguments!'); 59 | } 60 | if (typeof factOrPatternString !== 'string') { 61 | throw new Error('factOrPatternString must be a string!'); 62 | } 63 | let terms = this._parse(factOrPatternString); 64 | if (fillerValues.length > 0) { 65 | terms = terms.slice(); 66 | } 67 | for (let idx = 0; idx < terms.length; idx++) { 68 | const term = terms[idx]; 69 | if (term.hasOwnProperty('hole')) { 70 | if (fillerValues.length === 0) { 71 | throw new Error('not enough filler values!'); 72 | } 73 | terms[idx] = this._toJSONTerm(fillerValues.shift()); 74 | } 75 | } 76 | if (fillerValues.length > 0) { 77 | throw new Error('too many filler values!'); 78 | } 79 | return terms; 80 | } 81 | 82 | _toJSONTerm(value) { 83 | return value instanceof Term ? value.toJSON() : {value: value}; 84 | } 85 | 86 | _parse(factOrPatternString) { 87 | if (this._parseCache.has(factOrPatternString)) { 88 | return this._parseCache.get(factOrPatternString); 89 | } else { 90 | this._clearParseCacheIfTooBig(); 91 | const terms = parse(factOrPatternString); 92 | this._parseCache.set(factOrPatternString, terms); 93 | return terms; 94 | } 95 | } 96 | 97 | _clearParseCacheIfTooBig() { 98 | if (this._parseCache.size > MAX_PARSE_CACHE_SIZE) { 99 | this.clearParseCache(); 100 | } 101 | } 102 | 103 | clearParseCache() { 104 | this._parseCache.clear(); 105 | return this; 106 | } 107 | } 108 | 109 | module.exports = AbstractClient; 110 | -------------------------------------------------------------------------------- /src/Fact.js: -------------------------------------------------------------------------------- 1 | 'use strict'; 2 | 3 | const {Term, Variable, Wildcard} = require('./terms'); 4 | 5 | class Fact { 6 | constructor(terms) { 7 | this.terms = terms; 8 | } 9 | 10 | hasVariablesOrWildcards() { 11 | return this.terms.some(term => 12 | term instanceof Variable || 13 | term instanceof Wildcard); 14 | } 15 | 16 | match(that, env) { 17 | if (this.terms.length !== that.terms.length) { 18 | return null; 19 | } 20 | for (let idx = 0; idx < this.terms.length; idx++) { 21 | const thisTerm = this.terms[idx]; 22 | const thatTerm = that.terms[idx]; 23 | if (!thisTerm.match(thatTerm, env)) { 24 | return null; 25 | } 26 | } 27 | return env; 28 | } 29 | 30 | toString() { 31 | return this.terms.map(term => term.toString()).join(''); 32 | } 33 | } 34 | 35 | Fact.fromJSON = 36 | jsonTerms => new Fact(jsonTerms.map(jsonTerm => Term.fromJSON(jsonTerm))); 37 | 38 | module.exports = Fact; 39 | -------------------------------------------------------------------------------- /src/LocalClient.js: -------------------------------------------------------------------------------- 1 | 'use strict'; 2 | 3 | const AbstractClient = require('./AbstractClient'); 4 | const {Term} = require('./terms'); 5 | 6 | class LocalClient extends AbstractClient { 7 | constructor(db, id) { 8 | super(id); 9 | this._db = db; 10 | } 11 | 12 | select(...patternStrings) { 13 | const patterns = patternStrings.map(p => 14 | p instanceof Array ? 15 | this._toJSONFactOrPattern(...p) : 16 | this._toJSONFactOrPattern(p)); 17 | const solutions = this._db.select(...patterns); 18 | const results = { 19 | async do(callbackFn) { 20 | for (let solution of solutions) { 21 | for (let name in solution) { 22 | // force serialization and deserialization to simulate going over the network 23 | const json = JSON.parse(JSON.stringify(solution[name])); 24 | solution[name] = Term.fromJSON(json).toRawValue(); 25 | } 26 | await callbackFn(solution); 27 | } 28 | return results; 29 | }, 30 | async count() { 31 | return solutions.length; 32 | }, 33 | async isEmpty() { 34 | return solutions.length === 0; 35 | }, 36 | async isNotEmpty() { 37 | return solutions.length > 0; 38 | } 39 | }; 40 | return results; 41 | } 42 | 43 | async flushChanges() { 44 | this._retracts.forEach(pattern => this._db.retract(this._id, pattern)); 45 | this._retracts = []; 46 | this._asserts.forEach(fact => this._db.assert(this._id, fact)); 47 | this._asserts = []; 48 | return this; 49 | } 50 | 51 | async immediatelyRetractEverythingAbout(name) { 52 | return this._db.retractEverythingAbout(this._id, name); 53 | } 54 | 55 | async immediatelyRetractEverythingAssertedByMe() { 56 | return this._db.retractEverythingAssertedBy(this._id); 57 | } 58 | 59 | async getAllFacts() { 60 | return this._db.getAllFacts(); 61 | } 62 | 63 | toString() { 64 | return `[LocalClient ${this._id}]`; 65 | } 66 | } 67 | 68 | module.exports = LocalClient; 69 | -------------------------------------------------------------------------------- /src/RemoteClient.js: -------------------------------------------------------------------------------- 1 | 'use strict'; 2 | 3 | const AbstractClient = require('./AbstractClient'); 4 | const {Term} = require('./terms'); 5 | const parse = require('./parse'); 6 | 7 | // If fetch is not declared, load it from the node-fetch module. 8 | // (This makes it possible to run RemoteClient in the browser and in node-js.) 9 | const fetch = (() => { 10 | try { 11 | return fetch; 12 | } catch (e) { 13 | return require('node-fetch'); 14 | } 15 | })(); 16 | 17 | class RemoteClient extends AbstractClient { 18 | constructor(address, port, id) { 19 | super(id); 20 | this._address = address; 21 | this._port = port; 22 | } 23 | 24 | select(...patternStrings) { 25 | const patterns = patternStrings.map(p => 26 | p instanceof Array ? 27 | this._toJSONFactOrPattern(...p) : 28 | this._toJSONFactOrPattern(p)); 29 | const solutions = async () => { 30 | const params = `query=${JSON.stringify(patterns)}`; 31 | const response = await fetch(`http://${this._address}:${this._port}/facts?${params}`); 32 | return await response.json(); 33 | }; 34 | const results = { 35 | async do(callbackFn) { 36 | for (let solution of await solutions()) { 37 | for (let name in solution) { 38 | // force serialization and deserialization to simulate going over the network 39 | const json = JSON.parse(JSON.stringify(solution[name])); 40 | solution[name] = Term.fromJSON(json).toRawValue(); 41 | } 42 | await callbackFn(solution); 43 | } 44 | return results; 45 | }, 46 | async count() { 47 | return (await solutions()).length; 48 | }, 49 | async isEmpty() { 50 | return (await solutions()).length === 0; 51 | }, 52 | async isNotEmpty() { 53 | return (await solutions()).length > 0; 54 | } 55 | }; 56 | return results; 57 | } 58 | 59 | async flushChanges() { 60 | const retractions = this._retracts; 61 | const assertions = this._asserts; 62 | this._retracts = []; 63 | this._asserts = []; 64 | const params = 65 | 'clientId=' + this._id + '&' + 66 | 'retractions=' + JSON.stringify(retractions) + '&' + 67 | 'assertions=' + JSON.stringify(assertions); 68 | const response = await fetch( 69 | `http://${this._address}:${this._port}/facts?${params}`, 70 | {method: 'PUT'}); 71 | return await response.json(); 72 | } 73 | 74 | async immediatelyRetractEverythingAbout(name) { 75 | const response = await fetch( 76 | `http://${this._address}:${this._port}/facts?clientId=${this._id}&name=${name}`, 77 | {method: 'DELETE'}); 78 | return await response.json(); 79 | } 80 | 81 | async immediatelyRetractEverythingAssertedByMe() { 82 | const response = await fetch( 83 | `http://${this._address}:${this._port}/facts?clientId=${this._id}`, 84 | {method: 'DELETE'}); 85 | return await response.json(); 86 | } 87 | 88 | async getAllFacts() { 89 | const response = await fetch(`http://${this._address}:${this._port}/facts`); 90 | return await response.json(); 91 | } 92 | 93 | toString() { 94 | return `[RemoteClient ${this._address}:${this._port}, ${this._id}]`; 95 | } 96 | } 97 | 98 | module.exports = RemoteClient; 99 | -------------------------------------------------------------------------------- /src/RoomDB.js: -------------------------------------------------------------------------------- 1 | 'use strict'; 2 | 3 | const LocalClient = require('./LocalClient'); 4 | const Fact = require('./Fact'); 5 | const {Id} = require('./terms'); 6 | 7 | function flatten(obj) { 8 | for (let prop in obj) { 9 | obj[prop] = obj[prop]; 10 | } 11 | return obj; 12 | } 13 | 14 | class RoomDB { 15 | constructor() { 16 | this._factMap = new Map(); 17 | } 18 | 19 | select(...jsonPatterns) { 20 | const patterns = jsonPatterns.map(jsonPattern => Fact.fromJSON(jsonPattern)); 21 | const solutions = []; 22 | this._collectSolutions(patterns, Object.create(null), solutions); 23 | return solutions.map(flatten); 24 | } 25 | 26 | _collectSolutions(patterns, env, solutions) { 27 | if (patterns.length === 0) { 28 | solutions.push(env); 29 | } else { 30 | const pattern = patterns[0]; 31 | for (let fact of this._facts) { 32 | const newEnv = Object.create(env); 33 | if (pattern.match(fact, newEnv)) { 34 | this._collectSolutions(patterns.slice(1), newEnv, solutions); 35 | } 36 | } 37 | } 38 | } 39 | 40 | assert(clientId, factJSON) { 41 | const fact = Fact.fromJSON(factJSON); 42 | if (fact.hasVariablesOrWildcards()) { 43 | throw new Error('cannot assert a fact that has variables or wildcards!'); 44 | } 45 | fact.asserter = clientId; 46 | this._factMap.set(fact.toString(), fact); 47 | } 48 | 49 | retract(clientId, factJSON) { 50 | const pattern = Fact.fromJSON(factJSON); 51 | if (pattern.hasVariablesOrWildcards()) { 52 | const factsToRetract = 53 | this._facts.filter(fact => pattern.match(fact, Object.create(null))); 54 | factsToRetract.forEach(fact => this._factMap.delete(fact.toString())); 55 | return factsToRetract.length; 56 | } else { 57 | return this._factMap.delete(pattern.toString()) ? 1 : 0; 58 | } 59 | } 60 | 61 | retractEverythingAbout(clientId, name) { 62 | const id = Id.get(name); 63 | const emptyEnv = Object.create(null); 64 | const factsToRetract = 65 | this._facts.filter(fact => fact.terms.some(term => id.match(term, emptyEnv))); 66 | factsToRetract.forEach(fact => this._factMap.delete(fact.toString())); 67 | return factsToRetract.length; 68 | } 69 | 70 | retractEverythingAssertedBy(clientId) { 71 | const factsToRetract = this._facts.filter(fact => fact.asserter === clientId); 72 | factsToRetract.forEach(fact => this._factMap.delete(fact.toString())); 73 | return factsToRetract.length; 74 | } 75 | 76 | get _facts() { 77 | return Array.from(this._factMap.values()); 78 | } 79 | 80 | getAllFacts() { 81 | return this._facts.map(fact => fact.toString()); 82 | } 83 | 84 | toString() { 85 | return this._facts.map(fact => '<' + fact.asserter + '> ' + fact.toString()).join('\n'); 86 | } 87 | 88 | client(id = 'local-client') { 89 | return new LocalClient(this, id); 90 | } 91 | } 92 | 93 | module.exports = RoomDB; 94 | -------------------------------------------------------------------------------- /src/listen.js: -------------------------------------------------------------------------------- 1 | 'use strict'; 2 | 3 | const restify = require('restify'); 4 | const errors = require('restify-errors'); 5 | const corsMiddleware = require('restify-cors-middleware'); 6 | 7 | function listen(port = 8080) { 8 | const db = this; 9 | const server = restify.createServer({name: 'RoomDB'}); 10 | server.use(restify.plugins.queryParser()); 11 | 12 | const cors = corsMiddleware({origins: ['*']}); 13 | server.pre(cors.preflight); 14 | server.use(cors.actual); 15 | 16 | server.get('/facts', (req, res, next) => { 17 | try { 18 | if (req.query.query !== undefined) { 19 | const patterns = JSON.parse(req.query.query); 20 | const solutions = db.select(...patterns); 21 | res.send(solutions); 22 | next(); 23 | } else { 24 | res.send(db.getAllFacts()); 25 | next(); 26 | } 27 | } catch (e) { 28 | console.error('uh-oh:', e); 29 | next(e instanceof SyntaxError ? 30 | new errors.BadRequestError(e.message) : 31 | new errors.InternalServerError(e.message)); 32 | } 33 | }); 34 | 35 | server.put('/facts', (req, res, next) => { 36 | try { 37 | const retractions = req.query.retractions !== undefined ? 38 | JSON.parse(req.query.retractions) : 39 | []; 40 | const assertions = req.query.assertions !== undefined ? 41 | JSON.parse(req.query.assertions) : 42 | []; 43 | retractions.forEach(pattern => db.retract(req.query.clientId, pattern)); 44 | assertions.forEach(fact => db.assert(req.query.clientId, fact)); 45 | res.send('ok'); 46 | next(); 47 | } catch (e) { 48 | next(e instanceof SyntaxError ? 49 | new errors.BadRequestError(e.message) : 50 | new errors.InternalServerError(e.message)); 51 | } 52 | }); 53 | 54 | server.del('/facts', (req, res, next) => { 55 | if (req.query.name !== undefined) { 56 | db.retractEverythingAbout(req.query.clientId, req.query.name); 57 | } else { 58 | db.retractEverythingAssertedBy(req.query.clientId); 59 | } 60 | res.send('ok'); 61 | next(); 62 | }); 63 | 64 | server.listen(port, () => { 65 | console.log('%s listening at %s', server.name, server.url); 66 | }); 67 | 68 | return db; 69 | } 70 | 71 | module.exports = listen; 72 | -------------------------------------------------------------------------------- /src/parse.js: -------------------------------------------------------------------------------- 1 | 'use strict'; 2 | 3 | const ohm = require('ohm-js'); 4 | 5 | const grammar = ohm.grammar(` 6 | G { 7 | 8 | factOrPattern 9 | = term* 10 | 11 | term 12 | = id 13 | | word 14 | | value 15 | | variable 16 | | wildcard 17 | | hole 18 | 19 | id 20 | = upper alnum* 21 | 22 | value 23 | = keyword<"true"> -- true 24 | | keyword<"false"> -- false 25 | | keyword<"null"> -- null 26 | | number 27 | | string 28 | 29 | variable 30 | = "$" alnum+ 31 | 32 | wildcard 33 | = "*" 34 | 35 | hole 36 | = "_" 37 | 38 | word 39 | = (~special any)+ -- nonspace 40 | | space+ -- space 41 | 42 | keyword 43 | = k ~alnum 44 | 45 | number 46 | = float ("e" float)? 47 | 48 | float 49 | = integer ("." digit+)? 50 | 51 | integer 52 | = ("+" | "-")? digit+ 53 | 54 | string 55 | = "\\"" (~"\\"" ~"\\n" any)* "\\"" 56 | 57 | special 58 | = id | value | variable | wildcard | hole | space 59 | 60 | } 61 | `); 62 | 63 | const semantics = grammar.createSemantics().addOperation('parse', { 64 | factOrPattern(terms) { 65 | return terms.parse(); 66 | }, 67 | id(_1, _2) { 68 | return {id: this.sourceString}; 69 | }, 70 | value_true(_) { 71 | return {value: true}; 72 | }, 73 | value_false(_) { 74 | return {value: false}; 75 | }, 76 | value_null(_) { 77 | return {value: null}; 78 | }, 79 | variable(_, cs) { 80 | return {variable: cs.sourceString}; 81 | }, 82 | wildcard(_) { 83 | return {wildcard: true}; 84 | }, 85 | hole(_) { 86 | return {hole: true}; 87 | }, 88 | word_nonspace(_) { 89 | return {word: this.sourceString}; 90 | }, 91 | word_space(_) { 92 | return {word: ' '}; 93 | }, 94 | number(_1, _2, _3) { 95 | return {value: parseFloat(this.sourceString)}; 96 | }, 97 | string(_oq, cs, _cq) { 98 | const chars = []; 99 | let idx = 0; 100 | cs = cs.parse(); 101 | while (idx < cs.length) { 102 | let c = cs[idx++]; 103 | if (c === '\\' && idx < cs.length) { 104 | c = cs[idx++]; 105 | switch (c) { 106 | case 'n': c = '\n'; break; 107 | case 't': c = '\t'; break; 108 | default: idx--; 109 | } 110 | } 111 | chars.push(c); 112 | } 113 | return {value: chars.join('')}; 114 | }, 115 | _terminal() { 116 | return this.sourceString; 117 | } 118 | }); 119 | 120 | function parse(str, optRule) { 121 | const rule = optRule || 'factOrPattern'; 122 | const matchResult = grammar.match(str.trim(), rule); 123 | if (matchResult.succeeded()) { 124 | return semantics(matchResult).parse(); 125 | } else { 126 | console.log(str.trim()); 127 | console.log(matchResult.message); 128 | throw new Error(`invalid ${rule}: ${str}`); 129 | } 130 | }; 131 | 132 | module.exports = parse; 133 | -------------------------------------------------------------------------------- /src/roomdb-node.js: -------------------------------------------------------------------------------- 1 | 'use strict'; 2 | 3 | const RoomDB = require('./RoomDB'); 4 | RoomDB.prototype.listen = require('./listen'); 5 | 6 | module.exports = require('./roomdb-web'); 7 | -------------------------------------------------------------------------------- /src/roomdb-web.js: -------------------------------------------------------------------------------- 1 | 'use strict'; 2 | 3 | const RoomDB = require('./RoomDB'); 4 | const RemoteClient = require('./RemoteClient'); 5 | 6 | module.exports = { 7 | create() { 8 | return new RoomDB(); 9 | }, 10 | client(address, port, id = 'remote-client') { 11 | return new RemoteClient(address, port, id); 12 | } 13 | }; 14 | -------------------------------------------------------------------------------- /src/server.js: -------------------------------------------------------------------------------- 1 | 'use strict'; 2 | 3 | const roomdb = require('./roomdb-node'); 4 | 5 | let port; 6 | 7 | if (process.argv.length === 3) { 8 | port = parseInt(process.argv[2]); 9 | } else if (process.argv.length < 3) { 10 | port = 8080; 11 | } else { 12 | console.error('usage:', process.argv[0], process.argv[1], '[portNumber]'); 13 | process.exit(1); 14 | } 15 | 16 | roomdb.create().listen(port); 17 | -------------------------------------------------------------------------------- /src/terms.js: -------------------------------------------------------------------------------- 1 | 'use strict'; 2 | 3 | class Term { 4 | toString() { 5 | throw new Error('subclass responsibility'); 6 | } 7 | 8 | toJSON() { 9 | throw new Error('subclass responsibility'); 10 | } 11 | 12 | toRawValue() { 13 | throw new Error('subclass responsibility'); 14 | } 15 | 16 | match(that, env) { 17 | throw new Error('subclass responsibility'); 18 | } 19 | } 20 | 21 | Term.fromJSON = json => { 22 | if (json.hasOwnProperty('id')) { 23 | return Id.get(json.id); 24 | } else if (json.hasOwnProperty('word')) { 25 | return Word.get(json.word); 26 | } else if (json.hasOwnProperty('value')) { 27 | return new Value(json.value); 28 | } else if (json.hasOwnProperty('blobRef')) { 29 | return new BlobRef(json.blobRef); 30 | } else if (json.hasOwnProperty('variable')) { 31 | return new Variable(json.variable); 32 | } else if (json.hasOwnProperty('wildcard')) { 33 | return new Wildcard(); 34 | } else if (json.hasOwnProperty('hole')) { 35 | return new Hole(); 36 | } else { 37 | throw new Error('unrecognized JSON term: ' + JSON.stringify(json)); 38 | } 39 | }; 40 | 41 | class Id extends Term { 42 | static internedIds = new Map(); 43 | static get(name) { 44 | let id = this.internedIds.get(name); 45 | if (id == null) { 46 | id = new Id(name); 47 | this.internedIds.set(name, id); 48 | } 49 | return id; 50 | } 51 | 52 | constructor(name) { 53 | super(); 54 | this.name = name; 55 | } 56 | 57 | toString() { 58 | return this.name; 59 | } 60 | 61 | toJSON() { 62 | return {id: this.name}; 63 | } 64 | 65 | toRawValue() { 66 | return this; 67 | } 68 | 69 | match(that, env) { 70 | return that instanceof Id && this.name === that.name ? 71 | env : 72 | null; 73 | } 74 | } 75 | 76 | class Word extends Term { 77 | static internedWords = new Map(); 78 | static get(value) { 79 | let word = this.internedWords.get(value); 80 | if (word == null) { 81 | word = new Word(value); 82 | this.internedWords.set(value, word); 83 | } 84 | return word; 85 | } 86 | 87 | constructor(value) { 88 | super(); 89 | this.value = value; 90 | } 91 | 92 | toString() { 93 | return this.value; 94 | } 95 | 96 | toJSON() { 97 | return {word: this.value}; 98 | } 99 | 100 | toRawValue() { 101 | return this; 102 | } 103 | 104 | match(that, env) { 105 | return that instanceof Word && this.value === that.value ? 106 | env : 107 | null; 108 | } 109 | } 110 | 111 | class Value extends Term { 112 | constructor(value) { 113 | super(); 114 | this.value = value; 115 | } 116 | 117 | toString() { 118 | return JSON.stringify(this.value); 119 | } 120 | 121 | toJSON() { 122 | return {value: this.value}; 123 | } 124 | 125 | toRawValue() { 126 | return this.value; 127 | } 128 | 129 | match(that, env) { 130 | return that instanceof Value && this.value === that.value ? 131 | env : 132 | null; 133 | } 134 | } 135 | 136 | class BlobRef extends Term { 137 | constructor(id) { 138 | super(); 139 | this.id = id; 140 | } 141 | 142 | toString() { 143 | return '@' + this.id; 144 | } 145 | 146 | toJSON() { 147 | return {blobRef: this.id}; 148 | } 149 | 150 | toRawValue() { 151 | return this; 152 | } 153 | 154 | match(that, env) { 155 | return that instanceof BlobRef && this.id === that.id ? 156 | env : 157 | null; 158 | } 159 | } 160 | 161 | class Variable extends Term { 162 | constructor(name) { 163 | super(); 164 | this.name = name; 165 | } 166 | 167 | toString() { 168 | return '$' + this.name; 169 | } 170 | 171 | toJSON() { 172 | return {variable: this.name}; 173 | } 174 | 175 | toRawValue() { 176 | throw new Error('Variable\'s toRawValue() should never be called!'); 177 | } 178 | 179 | match(that, env) { 180 | if (env[this.name] === undefined) { 181 | env[this.name] = that; 182 | return env; 183 | } else { 184 | return env[this.name].match(that, env); 185 | } 186 | } 187 | } 188 | 189 | class Wildcard extends Term { 190 | constructor() { 191 | super(); 192 | // no-op 193 | } 194 | 195 | toString() { 196 | return '$'; 197 | } 198 | 199 | toJSON() { 200 | return {wildcard: true}; 201 | } 202 | 203 | toRawValue() { 204 | throw new Error('Wildcard\'s toRawValue() should never be called!'); 205 | } 206 | 207 | match(that, env) { 208 | return env; 209 | } 210 | } 211 | 212 | class Hole extends Term { 213 | constructor() { 214 | super(); 215 | // no-op 216 | } 217 | 218 | toString() { 219 | return '_'; 220 | } 221 | 222 | toJSON() { 223 | return {hole: true}; 224 | } 225 | 226 | toRawValue() { 227 | throw new Error('Hole\'s toRawValue() should never be called!'); 228 | } 229 | 230 | match(that, env) { 231 | throw new Error('Hole\'s match() should never be called!'); 232 | } 233 | } 234 | 235 | module.exports = { 236 | Term, 237 | Id, 238 | Word, 239 | Value, 240 | BlobRef, 241 | Variable, 242 | Wildcard, 243 | Hole 244 | }; 245 | --------------------------------------------------------------------------------