cel 0.2.0 has been released.
Pure Ruby implementation of Google Common Expression Language,
GitHub - google/cel-spec: Common Expression Language -- specification and binary representation.
The Common Expression Language (CEL) implements common semantics for
expression evaluation, enabling different applications to more easily
interoperate.
env = Cel::Environment.new(name: :string, group: :string)
ast = env.compile('name.startsWith("/groups/" + group)')
prg = env.program(ast)
return_value = prg.evaluate(name: Cel::String.new("/groups/
acme.co/documents/secret-stuff"),
group: Cel::String.new("acme.co")))
puts return_value #=> true
These are the announcements since the last release:
## [0.2.0] - 2023-01-17
### Features
#### Timestamp/Duration types
Implementing `Cel::Timestamp` and `Cel::Duration` CEL types, along with
support for functions for those types (such as `getDate`, `getDayOfYear`).
Cel::Environment.new.evaluate("timestamp('2022-12-25T00:00:00Z').getDate()")
#=> 25
Cel::Environment.new.evaluate("duration('3600s10ms').getHours()") #=> 1
#### Protobuf-to-CEL conversion
Support for auto-conversion of certain protobuf messages in the
`google.protobf` package to CEL types.
Cel::Environment.new.evaluate("google.protobuf.BoolValue{value: true}") #=>
true
Cel::Environment.new.evaluate("google.protobuf.Value{string_value: 'bla'}")
#=> "bla"
#### Custom Functions
`cel` supports the definition of custom functions in the environment, to be
used in expressions:
Cel::Environment.new(foo: Cel::Function(:int, :int, return_type: :int) {
> a, b| a + b }).evaluate("foo(2, 2)") #=> 4
### Expression encoding/decoding
Expressions can now be encoded and decoded, to improve storage / reparsing
to and from JSON, for example.
enc = Cel::Environment.new.encode("1 == 2") #=> ["op", ...
store_to_db(JSON.dump(enc))
# then, somewhere else
env = Cel::Environment.new
ast = env.decode(JSON.parse(read_from_db))
env.evaluate(ast) #=> 3
**NOTE**: This feature is only available in ruby 3.1 .
### Bugfixes
* fixed parser bug disallowing identifiers composed "true" or "false" (such
as "true_name").
## [0.1.2] - 2022-11-10
point release to update links in rubygems.
## [0.1.1] - 2022-08-11
* fixed handling of comparison of primmitive types with Cel types.
* fixed truffleruby compatibility by improving parser number handling.