CloudEvents Expression Language Go implementation

CloudEvents Expression Language implementation.

Note: this package is a work in progress, APIs might break in future releases.

User guide

To start using it:

import cesqlparser "github.com/cloudevents/sdk-go/sql/v2/parser"

// Parse the expression
expression, err := cesqlparser.Parse("subject = 'Hello world'")

// Res can be either int32, bool or string
res, err := expression.Evaluate(event)

Development guide

To regenerate the parser, make sure you have ANTLR4 installed and then run:

antlr4 -v 4.10.1 -Dlanguage=Go -package gen -o gen -visitor -no-listener CESQLParser.g4

Then you need to run this sed command as a workaround until this ANTLR issue is resolved. Without this, building for 32bit platforms will throw an int overflow error:

sed -i 's/(1<</(int64(1)<</g' gen/cesqlparser_parser.go