* libs/pubsub/query: specify peg version in go.mod
The code to generate the pubsub queries was dependent on an unspecified
version of the peg tool. This brings peg into go.mod so it is on a fixed
version. This should also enable dependabot to notify us of future
updates to peg.
The version of query.peg.go generated from the current version of peg
correctly contains the special "Code generated by..." line to indicate
to other tools that the file is automatically generated and should
therefore be excluded from linters, etc.
I removed the make target as there were no git grep results referencing
"gen_query_parser"; directly running "go generate" is a reasonable
expectation in Go projects.
Now that "go run" is module aware, I would typically use "go run" inside
the go:generate directive, but in this case we go build to a gitignore-d
directory in order to work around the nondeterministic output detailed
in pointlander/peg#129.
* libs/pubsub/query: check error from (*QueryParser).Init()
The newly generated peg code returns an error from Init(); the previous
version was niladic.
Co-authored-by: Sam Kleinman <garen@tychoish.com>
## Issue:
This PR adds an "EXISTS" condition to the event query grammar. It enables querying for the occurrence of an event without having to provide a condition for one of its attributes.
As an example, someone interested in all slashing events might currently catch them with a query such as slash.power > 0.
With this PR the event can be captured with slash.power EXISTS or just slash EXISTS to catch by event type.
## Examples:
`slash EXISTS`
## Commits:
* Add EXISTS condition to query grammar
* Gofmt files
* Move PEG instructions out of auto-generated file to prevent overwrite
* Update libs/pubsub/query/query.go
Co-Authored-By: Anton Kaliaev <anton.kalyaev@gmail.com>
* Update changelog and add test case
* Merge with other changes in PR #4070
* Add EXISTS to Conditions() func
* Apply gofmt
* Addressing PR comments
