Go code generator for Capnproto definitions. It integrates MsgPack and Capn'proto code generators. Code generation options available as annotations. Also this tool adds support for possible data validation.
HOW TO
You need Go 1.5 version. Set environment variable: GO15VENDOREXPERIMENT=1
.
-
Install
capnp
tool. See Instructions -
Install
caps
go get github.com/tpukep/caps/...
-
Write Capn'proto schema
model.capnp
:@0xad8d3cbc6db52a1d; using Go = import "/go.capnp"; $Go.package("model"); struct Book { title @0: Text; pageCount @1: Int32; authors @2: List(Text); content @3: Text; }
-
Generate Go plain code.
caps -source model.capnp
Annotations
Codecs
using Codec = import "/caps/codec.capnp";
# By default only plain Go code will be generated
# These annotations are enable extra features
$Codec.msgp; # Enables msgp code generation
$Codec.json; # Enables go json tags generation in plain Go code
$Codec.capnp; # Enables Capn'proto code generation
struct Person {
name @0 :Text;
email @1 :Text;
age @2 :UInt8;
phone @3 :Text;
}
Fields
using Field = import "/caps/field.capnp";
struct Person {
firstName @0 :Text $Field.required("name"); # Rename field to use more
# compact name in serialization code
email @1 :Text;
age @2 :UInt8 $Field.optional("pc"); # Mark as optional
phone @3 :Text $Field.ignored; # This field will be ignored
}
Checks
You can use Go-playground Validator expressions to generate tags in plain Go code. Note that $Field
tags also generate corresponding validate
tags.
Example of various checks
using Check = import "/caps/check.capnp";
struct Person $Go.doc("Some Person") {
name @0 :Text $Check.value("max=256,min=2");
email @1 :Text $Check.value("email");
age @2 :UInt8 $Check.value("max=40");
phone @3 :Text;
}
Examples of use located at demo/annotations.capnp
.