finalize dsl parser for now

src/fn.js

@@ -17,6 +17,8 @@ export const and = (...booleans) => booleans.every(identity)
 export const or = (...booleans) => booleans.some(identity)
 export const isOk = r => !is(Result, r) || r.isOk()
 
+export const construct = Type => args => new Type(...args)
+
 export const of = value => Array.isArray(value) ? value : [value]
 export const head = value => value[0]
 export const tail = value => value.slice(1)
@@ -29,6 +31,8 @@ export const find = curry((fn, v) => v.find(fn))
 export const join = curry((sep, v) => v.join(sep))
 export const rev = v => v.slice().reverse()
 export const pipe = (...f) => v => f.reduce(apply, v)
+export const prepend = curry((value, iter) => [value, ...iter])
+export const append = curry((value, iter) => [...iter, value])
 
 export const identity = x => x
 

src/parser.js

@@ -1,3 +1,4 @@
+import { inspect } from 'node:util'
 import { Result } from './result.js'
 import { Iterator, Stream } from './stream.js'
 import { curry, join, of } from './fn.js'

src/query.js

@@ -1,3 +0,0 @@
-// MATCH (a:Label)-[e:Label]->(b:Label)
-// RETURN a, b
-//

src/query/common.js

@@ -36,7 +36,7 @@ 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 ws = skip(many(Symbol.Space))
+export const ws = skip(many(any(Symbol.Newline, Symbol.Space)))
 export const identifier = map(([x]) => new Identifier(x), collect(seq(alpha, many(alphanumeric))))
 
 const float = map(([n]) => parseFloat(n, 10), collect(seq(signed, Symbol.Period, number)))

src/query/index.js

@@ -1,25 +1,30 @@
-import { head, is } from '../fn.js'
+import { construct, head, ifElse, is, pipe, prepend } from '../fn.js'
 import { map, maybe, seq } from '../parser.js'
+import { word } from './common.js'
 import { matchClause } from './match.js'
 import { returnClause } from './return.js'
 import { Query, SelectedGraph } from './types.js'
 import { useClause } from './use.js'
 
-const collect = args => {
-  return args
-  if (is(SelectedGraph, head(args))) {
-    return new Query(...args)
-  } else {
-    return new Query(undefined, ...args)
-  }
-}
+const hasUseClause = pipe(
+  head,
+  is(SelectedGraph)
+)
+
+const constructQuery = construct(Query)
+
+const collect = ifElse(
+  hasUseClause,
+  constructQuery,
+  pipe(prepend(undefined), constructQuery)
+)
 
 export const query = map(
   collect,
   seq(
     maybe(useClause),
-    matchClause,
-    returnClause
+    word(matchClause),
+    word(returnClause)
   )
 )
 

src/query/match.js

@@ -1,12 +1,12 @@
 import { identifier, literal, Symbol, ws } from './common.js'
 import { Node, Edge, KeyValuePair, Label, Name, Direction, DirectedEdge, Relationship } from './types.js'
-import { curry, filter, is } from '../fn.js'
+import { construct, curry, filter, is } from '../fn.js'
 import { many, maybe, map, seq, skip, between, noCaseString, separated, list, any } from '../parser.js'
 
 const { Bracket, Colon, Comma, Hyphen } = Symbol
 
 const name = map(
-  ([x]) => new Name(x),
+  construct(Name),
   identifier
 )
 
@@ -21,7 +21,7 @@ const bracketed = curry((value, { Left, Right }, state) => (
 ))
 
 const kvp = map(
-  ([k, v]) => new KeyValuePair(k, v),
+  construct(KeyValuePair),
   separated(name, trim(Colon), literal)
 )
 export const kvps = list(trim(Comma), kvp)

tests/query/match.test.js

@@ -1,4 +1,3 @@
-import util from 'node:util'
 import { describe, it } from 'node:test'
 import assert from '../assert.js'
 import { node, edge, matchClause } from '../../src/query/match.js'

tests/query/query.test.js

@@ -1,40 +1,73 @@
 import { describe, it } from 'node:test'
 import assert from '../assert.js'
 import { query } from '../../src/query/index.js'
-import { Identifier, Query, ReturnValues } from '../../src/query/types.js'
-import { makeEdge, makeNode } from '../utils.js'
+import { Alias, Identifier, ObjectPath, Query, ReturnValues, SelectedGraph } from '../../src/query/types.js'
+import { makeNode, makeRelationship, makeRightEdge } from '../utils.js'
 
-const i = n => new Identifier(n)
-const rv = (...v) => new ReturnValues(...v)
+const path = (...v) => new ObjectPath(...v)
+const alias = (...v) => new Alias(...v)
+const identifier = n => new Identifier(n)
+const graph = n => new SelectedGraph(identifier(n))
+const returnVals = (...v) => new ReturnValues(...v)
 const q = (u, m, rv) => new Query(u, m, rv)
 
 describe('query', () => {
-    //it('should match a node', () => {
-    //    assert.parseOk(query, 'MATCH (node:Label) RETURN node', ([actual]) => {
-    //        const expected = q(
-    //            undefined, // no use clause
-    //            makeNode('node', 'Label'),
-    //            rv(i('node'))
-    //        )
+    it('should match a node', () => {
+        assert.parseOk(query, 'MATCH (node:Label) RETURN node', ([actual]) => {
+            const expected = q(
+                undefined, // no use clause
+                makeNode('node', 'Label'),
+                returnVals(identifier('node'))
+            )
 
-    //        assert.deepEqual(actual, expected)
-    //    })
-    //})
+            assert.deepEqual(actual, expected)
+        })
+    })
 
     it('should match a relationship', () => {
-        assert.parseOk(query, 'MATCH (rown:Creature)-[:PETPATS]->(kbity:NetCat) RETURN rown, kbity', (actual) => {
-            console.log(actual)
-            //const expected = q(
-            //    undefined, // no use clause
-            //    [
-            //        makeNode('rown', 'Creature'),
-            //        makeEdge(undefined, 'PETPATS'),
-            //        makeNode('kbity', 'NetCat'),
-            //    ],
-            //    rv(i('rown'), i('kbity'))
-            //)
+        assert.parseOk(query, 'MATCH (rown:Creature)-[:Petpats]->(kbity:NetCat) RETURN rown, kbity', ([actual]) => {
+            const expected = q(
+                undefined, // no use clause
+                makeRelationship(
+                    makeNode('rown', 'Creature'),
+                    makeRightEdge(undefined, 'Petpats'),
+                    makeNode('kbity', 'NetCat'),
+                ),
+                returnVals(identifier('rown'), identifier('kbity'))
+            )
 
-            //assert.deepEqual(actual, expected)
+            assert.deepEqual(actual, expected)
+        })
+    })
+
+    it('should support the USE clause', () => {
+        assert.parseOk(query, 'USE aminals MATCH (kbity:Cat) RETURN kbity', ([actual]) => {
+            const expected = q(
+                graph('aminals'),
+                makeNode('kbity', 'Cat'),
+                returnVals(identifier('kbity'))
+            )
+
+            assert.deepEqual(actual, expected)
+        })
+    })
+
+    it('should support complex queries', () => {
+        assert.parseOk(query, 'USE aminals MATCH (kbity:Cat { type: "cute" })-[:Eats  { schedule: "daily" }]->(snacc:Feesh { type: "vegan", weight: 0.7 }) RETURN kbity.name AS name, snacc AS food', ([actual]) => {
+            const expected = q(
+                graph('aminals'),
+                makeRelationship(
+                    makeNode('kbity', 'Cat', [['type', 'cute']]),
+                    makeRightEdge(undefined, 'Eats', [['schedule', 'daily']]),
+                    makeNode('snacc', 'Feesh', [['type', 'vegan'], ['weight', 0.7]])
+                ),
+                returnVals(
+                    alias(path(identifier('kbity'), identifier('name')), identifier('name')),
+                    alias(identifier('snacc'), identifier('food'))
+                )
+            )
+
+            assert.deepEqual(actual, expected)
         })
     })
 })

tests/utils.js

@@ -11,5 +11,7 @@ export const graphObject = (name, label, props = [], Type = Node) => new Type(
 export const makeNode = graphObject
 export const makeEdge = (name, label, props = []) => graphObject(name, label, props, Edge)
 export const makeDirectedEdge = (name, label, direction, props = []) => DirectedEdge.fromEdge(makeEdge(name, label, props), direction)
+export const makeLeftEdge = (name, label, props = []) => DirectedEdge.fromEdge(makeEdge(name, label, props), 0)
+export const makeRightEdge = (name, label, props = []) => DirectedEdge.fromEdge(makeEdge(name, label, props), 1)
 export const makeRelationship = (from, edge, to) => new Relationship(from, edge, to)