Added backends

src/memory_backends/mod.rs

@@ -0,0 +1,31 @@
+use lsp_types::{
+    DidChangeTextDocumentParams, DidOpenTextDocumentParams, RenameFilesParams,
+    TextDocumentPositionParams,
+};
+
+use crate::configuration::{Configuration, ValidMemoryBackend};
+
+pub mod file_store;
+
+pub trait MemoryBackend {
+    fn init(&self) -> anyhow::Result<()> {
+        Ok(())
+    }
+    fn opened_text_document(&mut self, params: DidOpenTextDocumentParams) -> anyhow::Result<()>;
+    fn changed_text_document(&mut self, params: DidChangeTextDocumentParams) -> anyhow::Result<()>;
+    fn renamed_file(&mut self, params: RenameFilesParams) -> anyhow::Result<()>;
+    fn build_prompt(&self, position: &TextDocumentPositionParams) -> anyhow::Result<String>;
+}
+
+impl TryFrom<Configuration> for Box<dyn MemoryBackend + Send> {
+    type Error = anyhow::Error;
+
+    fn try_from(configuration: Configuration) -> Result<Self, Self::Error> {
+        match configuration.get_memory_backend()? {
+            ValidMemoryBackend::FileStore => {
+                Ok(Box::new(file_store::FileStore::new(configuration)))
+            }
+            _ => unimplemented!(),
+        }
+    }
+}