// The protohcl package aims to define a canonical way to translate between // protobuf and HCL encodings of data. // // Similar to google.golang.org/protobuf/encoding/protojson it intends to be // opinionated about what the canonical HCL representation of a protobuf type // should be. // // As HCL is a user centric data format as opposed to JSON/Protobuf which // are intended to be used more by machines, efficiency is not a primary goal // of this package as it is expected that users are either doing the encoding to and // decoding from HCL at the edge (such as within the Consul CLI) or that even // when done on servers, the rate that servers perform these translations should // be low enough to have any inefficiency produce a tangible performance impact. // // HCL has two different syntaxes that could be used to represent data: attribute and block // // This implementation chooses to represent primitive values, enums and the well known wrapper types and // collections of these values (maps and repeated fields) with attribute syntax. Other messages and collections // with message value types will be represented with block syntax for example // // message Foo { // map map_of_ints = 1; // map map_of_messages = 2; // } // // would have HCL like: // // map_of_ints = { // "foo": 1, // "bar": 2, // } // map_of_messages "foo" { // ...other fields // } // map_of_messages "bar" { // ...other fields // } // // Similar goes for list of primitives vs list of messages (except the block syntax uses no labels). The differences // between primitive fields outside of a collection and a message field really just amounts to not having to specify // the "=" between the field name and the "{" character. // // Field Mapping // | proto3 | HCL Type | example | notes | // |------------------------+---------------+---------+---------------------------------------------------------------------------------+ // | message | Object | | Represented as a block | // | enum | String | | | // | map | Map | | All keys are converted to/from strings. | // | repeated V | List | | | // | bool | Bool | | | // | string | String | | | // | bytes | base64 String | | | // | int32, fixed32, uint32 | Number | | | // | int64, fixed64, uint64 | Number | | | // | float, double | Number | | | // // ----- Well Known Types ----- // // | Any | Object | | | // | Timestamp | String | | RFC 3339 compliant | // | Duration | String | | String form is what would be accepted by time.ParseDuration | // | Struct | Map | | | // | Empty | Object | | An object with no fields | // | BoolValue | Bool | | Mostly the same as a regular bool except null values in the HCL are preserved | // | BytesValue | Bytes | | Mostly the same as a regular bytes except null values in the HCL are preserved | // | StringValue | String | | Mostly the same as a regular string except null values in the HCL are preserved | // | FloatValue | Number | | Mostly the same as a regular float except null values in the HCL are preserved | // | DoubleValue | Number | | Mostly the same as a regular double except null values in the HCL are preserved | // | Int32Value | Number | | Mostly the same as a regular int32 except null values in the HCL are preserved | // | UInt32Value | Number | | Mostly the same as a regular uint32 except null values in the HCL are preserved | // | Int64Value | Number | | Mostly the same as a regular int64 except null values in the HCL are preserved | // | UInt64Value | Number | | Mostly the same as a regular uint64 except null values in the HCL are preserved | // | FieldMask | String | | Each string of the FieldMask will be joined with a '.' | // package protohcl