Support reflection with the facet crate.

codec/Cargo.toml

@@ -41,6 +41,9 @@ serde = ["zalgo-codec-common/serde"]
 # Derives the `Serialize`, `Deserialize`, and `Archive` traits from [`rkyv`](https://crates.io/crates/rkyv) for the `ZalgoString` struct.
 rkyv = ["zalgo-codec-common/rkyv"]
 
+# Derives the `Facet` trait from [`facet`](https://crates.io/crates/facet) for the `ZalgoString` struct.
+facet = ["zalgo-codec-common/facet"]
+
 # Enables the proc-macros `zalgo_embed!` and `zalgofy!`
 macro = ["dep:zalgo-codec-macro"]
 

common/Cargo.toml

@@ -16,6 +16,7 @@ rust-version = "1.81.0"
 serde = { version = "1.0", default-features = false, features = ["alloc", "derive"], optional = true }
 rkyv = { version = "0.8", default-features = false, features = ["alloc", "bytecheck"], optional = true }
 bytecheck = { version = "0.8", default-features = false, optional = true }
+facet = { version = "0.8", default-features = false, features = ["alloc"], optional = true }
 
 [dev-dependencies]
 criterion = { version = "0.5", default-features = false, features = ["html_reports"] }
@@ -33,9 +34,12 @@ serde = ["dep:serde"]
 # Derives the `Serialize`, `Deserialize`, and `Archive` traits from [`rkyv`](https://crates.io/crates/rkyv) for the `ZalgoString` struct.
 rkyv = ["dep:rkyv", "dep:bytecheck"]
 
+# Derives the `Facet` trait from the [`facet`](https://crates.io/crates/facet) crate for the `ZalgoString` struct.
+facet = ["dep:facet"]
+
 # Enables the `Error` type to capture a `Backtrace`.
 # Without this feature the crate is `no_std` compatible, but still uses the `alloc` crate.
-std = ["serde?/std", "rkyv?/std", "bytecheck?/simdutf8"]
+std = ["serde?/std", "rkyv?/std", "bytecheck?/simdutf8", "facet?/std"]
 
 [[bench]]
 name = "codec_bench"

common/src/lib.rs

@@ -58,6 +58,8 @@
 //!
 //! `rkyv`: derives the [`rkyv::Serialize`], [`rkyv::Deserialize`], and [`rkyv::Archive`] traits from [`rkyv`] for [`ZalgoString`].
 //!
+//! `facet`: derives the [`Facet`](facet::Facet) trait from [`facet`] for [`ZalgoString`].
+//!
 //! # Explanation
 //!
 //! Characters U+0300–U+036F are the combining characters for unicode Latin.

common/src/zalgo_string/mod.rs

@@ -29,6 +29,8 @@ use alloc::{borrow::Cow, string::String, vec::Vec};
     derive(rkyv::Serialize, rkyv::Deserialize, rkyv::Archive, CheckBytes)
 )]
 #[cfg_attr(feature = "rkyv", bytecheck(verify))]
+#[cfg_attr(feature = "facet", derive(facet::Facet))]
+#[cfg_attr(feature = "facet", facet(invariants = "zalgo_string_invariants"))]
 pub struct ZalgoString(String);
 
 #[cfg(feature = "rkyv")]
@@ -71,6 +73,17 @@ impl Default for ZalgoString {
 }
 
 impl ZalgoString {
+    #[cfg(feature = "facet")]
+    /// Checks the invariants of the `ZalgoString` type
+    /// for use with reflection with `facet`.
+    fn zalgo_string_invariants(&self) -> bool {
+        !self.0.is_empty()
+            && core::str::from_utf8(self.0.as_bytes()).is_ok()
+            && self.0.as_bytes()[0] == b'E'
+            && self.0.len() % 2 == 1
+            && crate::zalgo_decode(&self.0).is_ok()
+    }
+
     /// Encodes the given string slice with [`zalgo_encode`] and stores the result in a new allocation.
     ///
     /// # Errors