Move experimental features to separate folder

.gitignore

@@ -1,3 +1,6 @@
 /target
 **/*.rs.bk
 Cargo.lock
+
+# IDEA
+/.idea/

Cargo.toml

@@ -38,6 +38,7 @@ base64_format = ["base64"]
 trace = ["futures", "rand", "pin-project"]
 metrics = ["prometheus"]
 serialize = ["serde", "bincode"]
+binary_propagator = []
 
 [workspace]
 members = [

src/api/context/propagation/mod.rs

@@ -160,9 +160,6 @@
 use crate::api;
 use std::collections::HashMap;
 
-#[cfg(feature = "base64")]
-pub mod base64_format;
-pub mod binary_propagator;
 pub mod composite_propagator;
 pub mod text_propagator;
 

src/api/mod.rs

@@ -20,12 +20,9 @@ pub mod metrics;
 pub mod trace;
 
 pub use self::core::{Key, KeyValue, Unit, Value};
-#[cfg(feature = "base64_format")]
-pub use context::propagation::base64_format::Base64Format;
 pub use context::{
     propagation::{
-        binary_propagator::BinaryFormat, composite_propagator::HttpTextCompositePropagator,
-        text_propagator::HttpTextFormat, Carrier,
+        composite_propagator::HttpTextCompositePropagator, text_propagator::HttpTextFormat, Carrier,
     },
     Context,
 };

src/experimental/api/context/mod.rs

@@ -0,0 +1,3 @@
+//! # OpenTelemetry Experimental Context API
+
+pub mod propagation;

src/api/context/propagation/base64_format.rs → src/experimental/api/context/propagation/base64_format.rs

@@ -7,7 +7,7 @@
 //! and deserializes values from base64 strings. There is a blanket implementation
 //! for any implementors of `BinaryFormat`
 use crate::api;
-use crate::api::BinaryFormat;
+use crate::experimental::api::BinaryFormat;
 use base64::{decode, encode};
 
 /// Used to serialize and deserialize `SpanContext`s to and from a base64

src/api/context/propagation/binary_propagator.rs → src/experimental/api/context/propagation/binary_propagator.rs

@@ -86,7 +86,6 @@ impl BinaryFormat for BinaryPropagator {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::api::BinaryFormat;
 
     #[rustfmt::skip]
     fn to_bytes_data() -> Vec<(api::SpanContext, [u8; 29])> {

src/experimental/api/context/propagation/mod.rs

@@ -0,0 +1,38 @@
+//! # OpenTelemetry Experimental Propagator interface
+//!
+//! ## Binary Format
+//!
+//! `BinaryFormat` is a formatter to serialize and deserialize a value
+//! into a binary format.
+//!
+//! `BinaryFormat` MUST expose the APIs that serializes values into bytes,
+//! and deserializes values from bytes.
+//!
+//! ### ToBytes
+//!
+//! Serializes the given value into the on-the-wire representation.
+//!
+//! Required arguments:
+//!
+//! - the value to serialize, can be `SpanContext` or `DistributedContext`.
+//!
+//! Returns the on-the-wire byte representation of the value.
+//!
+//! ### FromBytes
+//!
+//! Creates a value from the given on-the-wire encoded representation.
+//!
+//! If the value could not be parsed, the underlying implementation
+//! SHOULD decide to return ether an empty value, an invalid value, or
+//! a valid value.
+//!
+//! Required arguments:
+//!
+//! - on-the-wire byte representation of the value.
+//!
+//! Returns a value deserialized from bytes.
+//!
+
+#[cfg(feature = "base64")]
+pub mod base64_format;
+pub mod binary_propagator;

src/experimental/api/mod.rs

@@ -0,0 +1,8 @@
+//! ## OpenTelemetry Experimental API: What applications use and SDKs implement.
+
+pub mod context;
+
+#[cfg(feature = "base64_format")]
+pub use context::propagation::base64_format::Base64Format;
+#[cfg(feature = "binary_propagator")]
+pub use context::propagation::binary_propagator::BinaryFormat;

src/experimental/mod.rs

@@ -0,0 +1,3 @@
+//! # OpenTelemetry Experimental Features
+
+pub mod api;

src/lib.rs

@@ -221,6 +221,7 @@
 #![cfg_attr(test, deny(warnings))]
 
 pub mod api;
+pub mod experimental;
 pub mod exporter;
 pub mod global;
 pub mod sdk;