Cyphoid 0.8.0

C# Cyphoid parser for Cypher query language

This project implements a Cypher parser that can be used in C# to query any sort of graph backend.

Cyphoid expects developers to implement various operators that interact with their own backend.

Features

• Implements a subset of Cyhper.
• Fast parser implementation with Antlr.
• In-memory implementation of query plans for any backend.

Example usage

// This is your implementation of the backend
IOperatorFactory factory = new OperatorFactory(Graph);

// Query input
var input = "MATCH (n:city) RETURN n.name LIMIT 1";

// Parse query
ICypherParser parser = new CypherAstParser();
var queryNode = parser.ParseQuery(input);

// Print parsed query
var prettyPrint = queryNode.PrettyPrint();

// Build logical query plan
var plan = queryNode.BuildQueryPlan();

// Build executable query plan (using your backend)
var execution = plan.BuildExecutionPlan(factory);

// Prepare query context
var context = new QueryContext(queryNode.RowSize);

// Execute actual query
var result = await execution.ExecuteAsync(context).ToListAsync();

Architecture

Source Code
   ↓
ANTLR Lexer/Parser
   ↓
AST Builder (Visitor)
   ↓
Abstract Syntax Tree (AST)
   ↓
Cypher logical plan
   ↓
Cypher executable query plan
   ↓
<Your implementation>

Backend implementation

Guidance for third-party backends is in BACKEND_GUIDE.md.

Developer instructions

For developing the Cyphoid library.

Building a release

1. Update version number and more in Cyphoid.Core.csproj.
2. Build in release mode to generate NuGet package.
3. Upload package Cyphoid.N.N.N.nupkg from Src\Cyphoid.Core\bin\Release\ folder.

ANTLR

The compiler is built using Antlr. See https://github.com/antlr/antlr4/blob/master/doc/getting-started.md

Antlr is made with Java. There are some Windows tools that make setup easier. See https://github.com/antlr/antlr4-tools

Run ANTLR Compiler

cd into "Cyphoid.Core/Antlr".

java org.antlr.v4.Tool -Dlanguage=CSharp -visitor -o Generated Cypher.g4

Manual Antlr installation

Install Java (version 1.7 or higher) - NOT from java.com but rather one of the newer SDKs.

Download antlr-4.13.2-complete.jar (or whatever version) from https://www.antlr.org/download.html Save to your directory for 3rd party Java libraries, say C:\Javalib

Add antlr-4.13.2-complete.jar to CLASSPATH, either: Permanently: Using System Properties dialog > Environment variables > Create or append to CLASSPATH variable Temporarily, at command line.