feat(definitions): Add a implementation of the specification in Rust

definitions/rust/src/lib.rs

@@ -0,0 +1 @@
+mod specification;

definitions/rust/src/specification.rs

@@ -0,0 +1,29 @@
+//! # Specification
+//!
+//! An `serde`-based implementation of the entity generation specification.
+//! 
+
+use std::collections::HashMap;
+
+use serde::Deserialize;
+
+#[derive(Debug, Clone, Deserialize)]
+pub struct SpecificationRoot {
+    pub name: String,
+    pub location: RustAndKotlinType,
+    pub feature_flag: String,
+    pub fields: HashMap<String, SpecificationField>
+}
+
+#[derive(Debug, Clone, Deserialize)]
+pub struct RustAndKotlinType {
+    pub rust: String,
+    pub kotlin: String
+}
+
+#[derive(Debug, Clone, Deserialize)]
+pub struct SpecificationField {
+    pub kind: RustAndKotlinType,
+    #[serde(default)]
+    pub sql: Option<String>,
+}