SignalFlow language grammar

This repository contains the SignalFx SignalFlow language grammar and the structure and tools required to generate the public code artifacts that make this grammar available in various languages.

The language is in ANTLR4 format and we use the antlr tool to generate the corresponding source code for the target languages. From there, we can build artifacts that can be included as dependencies in various projects that need to parse SignalFlow programs.

Note: if you're looking to use the grammar, you should use one of the generated artifacts instead of this repository.

Available languages

Java

The com.signalfx.public:signalflow-grammar artifact Jar is available on Maven Central:

<dependency>
  <groupId>com.signalfx.public</groupId>
  <artifactId>signalflow-grammar</artifactId>
  <version>2.12.0</version>
</dependency>

Javascript

The library is available for npm.js, and as a standalone browserified Javascript bundle.

Node.js

npm install -g signalflow-grammar.js

In browser

<script type="text/javascript" src="https://s3.amazonaws.com/public-sites--signalfx-com/cdn/signalflow-grammar-2.7.0.js"></script>

Python

The library is available on PyPI and depends on the Python2 ANTLR runtime:

$ pip install signalflow-grammar==2.7.0

Then, from your code, you can do:

import antlr4
from signalflow.grammar.SignalFlowV2Lexer import SignalFlowV2Lexer
from signalflow.grammar.SignalFlowV2Parser import SignalFlowV2Parser

def parse(program):
    lexer = SignalFlowV2Lexer(program)
    stream = antlr4.CommonTokenStream(lexer)
    parser = SignalFlowV2Parser(stream)
    ...

Generating or updating the artifacts

Due to the Python like nature of SignalFlow some native code is required to keep track of indent/dedent levels. This native code is stored in <language>/grammar/*.g4. These native code files are stitched into SignalFlowLexer.g4 by the generate_grammar.py script.

Update the generated source code with the generate.sh script:

$ ./generate.sh <version>
$ git commit -a -m "Bump to version <version>"
$ git push origin master

Then for each language, perform a release of the corresponding package.

Java

$ cd java/
$ mvn clean deploy -P release-sign-artifacts -DperformRelease=true -DrepositoryId=ossrh -Dgpg.useagent=false

Javascript

$ cd javascript/
$ npm publish
$ aws s3 cp signalflow-grammar-<version>.js s3://public-sites--signalfx-com/cdn/

Python

$ cd python/
$ python setup.py bdist_wheel
$ twine upload dist/signalflow_grammar-<version>-py2-none-any.whl