go-dfl

README

go-dfl

Description

go-dfl is a Go implementation of the Dynamic Filter Language (DFL). go-dfl depends on:

• go-adaptive-functions for many of the basic functions.
• go-reader-writer for reading and writer files.
• go-counter for counting for statistical functions.
• go-try-get for abstracting how to get values by name from unknown objects.

Using cross compilers, this library can also be called by other languages. This library is cross compiled into a Shared Object file (*.so). The Shared Object file can be called by C, C++, and Python on Linux machines. See the examples folder for patterns that you can use. This library is also compiled to pure JavaScript using GopherJS.

Usage

CLI

The command line tool, dfl, can be used to easily covert data between formats. We currently support the following platforms.

GOOS	GOARCH
darwin	amd64
linux	amd64
windows	amd64
linux	arm64

Pull requests to support other platforms are welcome! See the examples section below for usage.

Go

You can install the go-dfl packages with.

go get -u -d github.com/spatialcurrent/go-dfl/...

You can then import the dfl package with:

import (
  "github.com/spatialcurrent/go-dfl/pkg/dfl"
)

See dfl in GoDoc for information on how to use Go API.

Node

DFL is built as a module. In modern JavaScript, the module can be imported using destructuring assignment.

const { parse, compile, evaluate } = require('./dist/dfl.mod.min.js');

In legacy JavaScript, you can use the dfl.global.js file that simply adds dfl to the global scope.

C

A variant of the reader and writer functions are exported in a Shared Object file (*.so), which can be called by C, C++, and Python programs on Linux machines. For complete patterns for C, C++, and Python, see the examples folder in this repo.

Releases

go-dfl is currently in alpha. See releases at https://github.com/spatialcurrent/go-dfl/releases. See the Building section below to build from scratch.

JavaScript

• dfl.global.js, dfl.global.js.map - JavaScript global build with source map
• dfl.global.min.js, dfl.global.min.js.map - Minified JavaScript global build with source map
• dfl.mod.js, dfl.mod.js.map - JavaScript module build with source map
• dfl.mod.min.js, dfl.mod.min.js.map - Minified JavaScript module with source map

Darwin

• dfl_darwin_amd64 - CLI for Darwin on amd64 (includes macOS and iOS platforms)

Linux

• dfl_linux_amd64 - CLI for Linux on amd64
• dfl_linux_amd64 - CLI for Linux on arm64
• dfl_linux_amd64.h, dfl_linuxamd64.so - Shared Object for Linux on amd64
• dfl_linux_armv7.h, dfl_linux_armv7.so - Shared Object for Linux on ARMv7
• dfl_linux_armv8.h, dfl_linux_armv8.so - Shared Object for Linux on ARMv8

Windows

• dfl_windows_amd64.exe - CLI for Windows on amd64

Examples:

Go

See the examples in the dfl package documentation.

CLI

Environment

With the -env flag you can use DFL filters against the current environment.

./dfl -env -f '@SHELL in [/bin/sh, /bin/bash]' && echo "Shell is set to sh or bash"

Arrays

You can use DFL to filter integer arrays.

./dfl -f '@a == [1, 2, 3, 4]' 'a=[1, 2, 3, 4]'
# returns true as exit code 0

You can also use DFl to compare byte arrays.

./dfl -f '@a == [137, 80, 78, 71]' 'a=[0x89, 0x50, 0x4E, 0X47]'
# returns true as exit code 0

IP Address Information

You can use DFL to filter IP addresses.

./dfl -f '@ip in 10.10.0.0/16' ip=10.10.20.22
# returns true as exit code 0

OpenStreetMap

You can also use DFL to filter OpenStreetMap features.

./dfl -f '@pop > (10 - 2)' craft=brewery name=Stone pop=10
# returns true as exit code 0

./dfl -f '@craft like "brewery"' craft=brewery name=Stone pop=10
# returns true as exit code 0

./dfl -f '@craft like "brew%"' craft=brewery name=Stone pop=10
# returns true as exit code 0

./dfl -f '@craft ilike "Stone%"' craft=brewery name=Atlas pop=10
# returns true as exit code 0

Building

Use make help to see help information for each target.

CLI

The make build_cli script is used to build executables for Linux and Windows.

JavaScript

You can compile DFL to pure JavaScript with the make build_javascript script.

Shared Object

The make build_so script is used to build Shared Objects (*.so), which can be called by C, C++, and Python on Linux machines.

Changing Destination

The default destination for build artifacts is go-dfl/bin, but you can change the destination with an environment variable. For building on a Chromebook consider saving the artifacts in /usr/local/go/bin, e.g., DEST=/usr/local/go/bin make build_cli

Testing

Go

To run Go tests use make test_go (or bash scripts/test.sh), which runs unit tests, go vet, go vet with shadow, errcheck, ineffassign, staticcheck, and misspell.

JavaScript

To run JavaScript tests, first install Jest using make deps_javascript, use Yarn, or another method. Then, build the JavaScript module with make build_javascript. To run tests, use make test_javascript. You can also use the scripts in the package.json.

Contributing

Spatial Current, Inc. is currently accepting pull requests for this repository. We'd love to have your contributions! Please see Contributing.md for how to get started.

License

This work is distributed under the MIT License. See LICENSE file.