break apart parser logic; add tests

package.json

@@ -5,7 +5,7 @@
   "type": "module",
   "scripts": {
     "start": "node src/index.js",
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "test": "node --test ./tests"
   },
   "keywords": [],
   "author": "",

src/parser.js

@@ -63,10 +63,6 @@ const succeed = curry((v, [p, rest]) => Result.Ok([p.concat(of(v)), rest]))
 const fail = curry((msg, state, err = undefined) => Result.Err(new ParseError(msg, state, err)))
 
 const next = ([, rest]) => rest.next()
-// b.len - a.len
-// b.slice(-diff)
-//const difflen = result.value[0].length - parsed.length
-//console.log(difflen, result.value[0], result.value[0].slice(-difflen))
 const diff = ([a], [b]) => b.slice(-Math.max(0, b.length - a.length))
 const tokenize = str => str.split('')
 const tokenizeInto = curry((fn, str) => tokenize(str).map(v => fn(v)))
@@ -100,6 +96,21 @@ export const any = (...parsers) => (state) => {
   return fail('no matching parsers', state)
 }
 
+export const until = curry((parser, state) => {
+  let acc = Result.Ok(state)
+
+  while (acc.isOk()) {
+    const result = parser(clone(acc.value))
+    if (result.isOk()) {
+      break
+    } else {
+      acc = anyChar(acc.value)
+    }
+  }
+
+  return acc
+})
+
 export const many = curry((parser, state) => {
   let result = Result.Ok(state)
 
@@ -146,6 +157,11 @@ export const map = curry((fn, parser, state) => {
 })
 
 
+export const anyChar = state => {
+  const ch = next(state)
+  return !!ch ? succeed(ch, state) : fail('end of stream', state)
+}
+
 export const char = curry((ch, state) => {
   return next(state) === ch ? succeed(ch, state) : fail(`could not parse ${ch}`, state)
 })
@@ -158,15 +174,27 @@ export const string = curry((str, state) =>
   map(join(''), seq(...tokenizeInto(char, str)))(state)
 )
 
-export const anyChar = curry((str, state) =>
+export const anyOf = curry((str, state) =>
   any(...tokenizeInto(char, str))(state)
 )
 
-export const digit = anyChar(Digits)
+export const between = curry((left, value, right, state) => (
-export const lowerAlpha = anyChar(LowerAlpha)
+  seq(skip(left), value, skip(right))(state)
-export const upperAlpha = anyChar(UpperAlpha)
+))
-export const alpha = anyChar(Alpha)
+
-export const alphanumeric = anyChar(Alphanumeric)
+export const separated = curry((a, sep, b, state) => (
+  seq(a, skip(sep), b)(state)
+))
+
+export const list = curry((sep, value, state) => (
+  seq(value, many(seq(skip(sep), value)))(state)
+))
+
+export const digit = anyOf(Digits)
+export const lowerAlpha = anyOf(LowerAlpha)
+export const upperAlpha = anyOf(UpperAlpha)
+export const alpha = anyOf(Alpha)
+export const alphanumeric = anyOf(Alphanumeric)
 
 export const noCaseString = curry((str, state) => (
   seq(...tokenizeInto(noCaseChar, str))(state)

src/query.js

@@ -1,73 +1,3 @@
-import { join } from './fn.js'
-import { alpha, alphanumeric, any, char, many, map, noCaseString, parse, seq, skip } from './parser.js'
-
 // MATCH (a:Label)-[e:Label]->(b:Label)
 // RETURN a, b
-
+//
-const Identifier = (name, label) => ({ name, label })
-
-const ObjectType = Object.freeze({
-  Node: 0,
-  Edge: 1
-})
-
-const GraphObject = ({ name, label }, type, properties = []) => Object.freeze({
-  name,
-  label,
-  type,
-  properties
-})
-
-const whitespace = char(' ')
-const matchKeyword = noCaseString('match')
-const returnKeyword = noCaseString('return')
-
-const name = map(
-  join(''),
-  seq(alpha, many(alphanumeric))
-)
-const colon = char(':')
-const label = seq(skip(colon), name)
-
-const id = any(
-  map(
-    ([name, label]) => Identifier(name, label),
-    seq(name, label)
-  ),
-  map(
-    ([name]) => Identifier(name),
-    name
-  ),
-  map(
-    ([label]) => Identifier(undefined, label),
-    label
-  )
-)
-
-const lparen = char('(')
-const rparen = char(')')
-const node = map(
-  ([id]) => GraphObject(id, ObjectType.Node),
-  seq(skip(lparen), id, skip(rparen))
-)
-
-const lsquare = char('[')
-const rsquare = char(']')
-const edge = map(
-  ([id]) => GraphObject(id, ObjectType.Edge),
-  seq(skip(lsquare), id, skip(rsquare))
-)
-
-const hyphen = char('-')
-const rchevron = char('>')
-const arrow = seq(hyphen, rchevron)
-const relationship = seq(skip(hyphen), edge, skip(arrow), node)
-
-const matchParameters = seq(node, many(relationship))
-const matchStmt = seq(skip(matchKeyword), skip(many(whitespace)), matchParameters)
-
-const query = 'MATCH (:Label)-[e:Label]->(b:Label)'
-const result = parse(matchStmt, query)
-console.log(result.value[0])
-
-

src/query/common.js

@@ -0,0 +1,51 @@
+import { join } from '../fn.js'
+import { alpha, alphanumeric, any, char, digit, list, many, map, maybe, noCaseString, separated, seq, skip, string, until } from '../parser.js'
+
+export const Symbol = Object.freeze({
+  Bracket: Object.freeze({
+    Angle: Object.freeze({
+      Left: char('<'),
+      Right: char('>')
+    }),
+    Curly: Object.freeze({
+      Left: char('{'),
+      Right: char('}'),
+    }),
+    Round: Object.freeze({
+      Left: char('('),
+      Right: char(')'),
+    }),
+    Square: Object.freeze({
+      Left: char('['),
+      Right: char(']'),
+    }),
+  }),
+  Colon: char(':'),
+  Comma: char(','),
+  Hyphen: char('-'),
+  Newline: char('\n'),
+  Period: char('.'),
+  Plus: char('+'),
+  Space: char(' '),
+  Quote: char('"')
+})
+
+
+
+export const collect = parser => map(join(''), parser)
+export const quoted = collect(seq(skip(Symbol.Quote), until(Symbol.Quote), skip(Symbol.Quote)))
+export const number = seq(digit, many(digit))
+export const signed = seq(maybe(any(Symbol.Plus, Symbol.Hyphen)), number)
+export const toBoolean = v => v === 'false' ? false : true
+
+export const Literal = Object.freeze({
+  Float: map(([n]) => parseFloat(n, 10), collect(seq(signed, Symbol.Period, number))),
+  Integer: map(([n]) => parseInt(n, 10), collect(signed)),
+  String: quoted,
+  Boolean: map(([v]) => toBoolean(v), any(string('true'), string('false')))
+})
+
+export const literal = any(...Object.values(Literal))
+export const ws = skip(many(Symbol.Space))
+export const identifier = map(join(''), seq(alpha, many(alphanumeric)))
+export const accessor = seq(identifier, list(Symbol.Period, identifier))

src/query/match.js

@@ -0,0 +1,52 @@
+import { Symbol, ws } from './common.js'
+import { Identifier, Node, Edge, KeyValuePair } from './types.js'
+import { curry, join } from '../fn.js'
+import { alpha, alphanumeric, many, maybe, map, parse, seq, skip, between, noCaseString, separated, until, list } from '../parser.js'
+
+const { Bracket, Colon, Comma, Hyphen, Quote } = Symbol
+
+const name = map(
+  join(''),
+  seq(alpha, many(alphanumeric))
+)
+const label = seq(skip(Colon), name)
+
+const trim = curry((parser, state) => (
+  between(ws, parser, ws, state)
+))
+
+const bracketed = curry((value, { Left, Right }, state) => (
+  between(trim(Left), value, trim(Right), state)
+))
+
+const quoted = map(join(''), seq(skip(Quote), until(Quote), skip(Quote)))
+const kvp = map(
+  ([k, v]) => new KeyValuePair(k, v),
+  separated(name, trim(Colon), quoted)
+)
+const kvps = list(trim(Comma), kvp)
+export const properties = bracketed(kvps, Bracket.Curly)
+
+const id = map(
+  ([name, label]) => new Identifier(name, label),
+  seq(maybe(name), label)
+)
+
+
+export const node = map(
+  ([id, ...properties]) => new Node(id, properties),
+  bracketed(seq(id, ws, maybe(properties)), Bracket.Round)
+)
+
+export const edge = map(
+  ([id]) => new Edge(id),
+  bracketed(id, Bracket.Square)
+)
+
+const rightArrow = seq(Hyphen, Bracket.Angle.Right)
+const relationship = seq(skip(Hyphen), edge, skip(rightArrow), node)
+
+const keyword = noCaseString('match')
+const params = seq(node, many(relationship))
+export const statement = seq(skip(keyword), ws, params)
+

src/query/return.js

@@ -0,0 +1,17 @@
+import { ReturnValues } from './types.js'
+import { list, map, maybe, noCaseString, parse, seq, skip } from '../parser.js'
+import { accessor, identifier, Symbol, ws } from './common.js'
+
+const as = noCaseString('as')
+const alias = seq(as, identifier)
+const aliasId = seq(accessor, maybe(alias))
+
+const keyword = noCaseString('return')
+
+const params = map(
+  values => new ReturnValues(values),
+  seq(list(seq(Symbol.Comma, ws), aliasId))
+)
+
+export const statement = seq(skip(keyword), ws, params)
+

src/query/types.js

@@ -0,0 +1,56 @@
+export class Identifier {
+  constructor(name, label) {
+    if (label == null) {
+      this.label = name
+    } else {
+      this.name = name
+      this.label = label
+    }
+  }
+}
+
+export class SelectedGraph {
+  constructor(identifier) {
+    this.identifier = identifier
+  }
+}
+
+class GraphObject {
+  constructor({ name, label }, properties = []) {
+    this.name = name
+    this.label = label
+    this.properties = properties
+  }
+}
+
+export class Node extends GraphObject {
+  constructor(id, properties) {
+    super(id, properties)
+  }
+}
+
+export class Edge extends GraphObject {
+  constructor(id, properties) {
+    super(id, properties)
+  }
+}
+
+export class ReturnValues extends Array {
+  constructor(args) {
+    super(args)
+  }
+}
+
+export class KeyValuePair {
+  constructor(key, value) {
+    this.key = key
+    this.value = value
+  }
+}
+
+export class Alias {
+  constructor(value, alias) {
+    this.value = value
+    this.alias = alias
+  }
+}

src/query/use.js

@@ -0,0 +1,11 @@
+import { identifier, ws } from './common.js'
+import { map, noCaseString, parse, seq, skip } from '../parser.js'
+import { SelectedGraph } from './types.js'
+
+const keyword = noCaseString('use')
+
+export const statement = map(
+  ([graph]) => new SelectedGraph(graph),
+  seq(skip(keyword), ws, identifier)
+)
+

tests/query/common.test.js

@@ -0,0 +1,30 @@
+import { describe, it } from 'node:test'
+import assert from 'node:assert'
+import { digit, many, parse, seq } from '../../src/parser.js'
+import * as Common from '../../src/query/common.js'
+
+describe('common parser library', () => {
+    it('literals should match literal types', () => {
+        const tBool = parse(Common.literal, 'true')
+        const fBool = parse(Common.literal, 'false')
+        const uint = parse(Common.literal, '5')
+        const posInt = parse(Common.literal, '+16')
+        const negInt = parse(Common.literal, '-710')
+        const ufloat = parse(Common.literal, '2.1')
+        const posFloat = parse(Common.literal, '+0.1')
+        const negFloat = parse(Common.literal, '-12.01')
+        const string = parse(Common.literal, '"akjsdfuaio"')
+
+        const v = r => r.value[0][0]
+        assert.strictEqual(v(tBool), true)
+        assert.strictEqual(v(fBool), false)
+        assert.strictEqual(v(uint), 5)
+        assert.strictEqual(v(posInt), 16)
+        assert.strictEqual(v(negInt), -710)
+        assert.strictEqual(v(ufloat), 2.1)
+        assert.strictEqual(v(posFloat), 0.1)
+        assert.strictEqual(v(negFloat), -12.01)
+        assert.strictEqual(v(string), 'akjsdfuaio')
+    })
+})
+

tests/query/match.test.js

@@ -0,0 +1,21 @@
+import { describe, it } from 'node:test'
+import assert from 'node:assert'
+import { parse } from '../../src/parser.js'
+import { node, edge, properties, statement } from '../../src/query/match.js'
+
+//describe('match parser', () => {
+//    it('node should match a label', () => {
+//        const result = parse(node, '(:Node)')
+//        console.log(result.error.state)
+//        assert(result.isOk())
+//    })
+//
+//    it('properties should do something', () => {
+//        const q = '(a:Node { name: "Rowan", species: "???" })'
+//        console.log(
+//            `parsing "${q}"\n`,
+//            parse(node, q).value[0][0]
+//        )
+//    })
+//})
+

tests/query/return.test.js

@@ -0,0 +1,23 @@
+import { describe, it } from 'node:test'
+import assert from 'node:assert'
+import { parse } from '../../src/parser.js'
+import { statement } from '../../src/query/return.js'
+
+describe('return parser', () => {
+    it('should collect a single value for a query to return', () => {
+        const result = parse(statement, 'RETURN folklore AS f')
+        console.log(result.error)
+        assert(result.isOk())
+        const [[selected]] = result.value
+        assert.deepStrictEqual(selected, ['folklore'])
+    })
+
+    //it('should collect multiple values for a query to return', () => {
+    //    const result = parse(statement, 'RETURN sybil, mercury, rowan')
+    //    console.log(result.error.state[0])
+    //    assert(result.isOk())
+    //    const [[selected]] = result.value
+    //    assert.deepStrictEqual(selected, ['sybil', 'mercury', 'rowan'])
+    //})
+})
+

tests/query/use.test.js

@@ -0,0 +1,19 @@
+import { describe, it } from 'node:test'
+import assert from 'node:assert'
+import { parse } from '../../src/parser.js'
+import { statement } from '../../src/query/use.js'
+
+describe('use parser', () => {
+    it('should select a graph to query', () => {
+        const result = parse(statement, 'USE default')
+        assert(result.isOk())
+        const [[selected]] = result.value
+        assert.strictEqual(selected.identifier, 'default')
+    })
+
+    it('should return an error if no graph identifier is provided', () => {
+        const result = parse(statement, 'USE')
+        assert(result.isErr())
+    })
+})
+

tests/run.js

@@ -0,0 +1,10 @@
+import { tap } from 'node:test/reporters'
+import { run } from 'node:test'
+import path from 'node:path'
+
+run({ files: [path.resolve('./tests/query/use.js')] })
+	.on('test:fail', () => {
+		process.exitCode = 1
+	})
+	.compose(tap)
+	.pipe(process.stdout)