Implement SheetSystem core library

Add IndexSource type for resource addressing and implement mapping
system
with LocalMapping, Mapping, and MappingBuf types. Create Sheet and
SheetData
structs for managing sheet data with editing capabilities.

Implement binary format serialization/deserialization with reader and
writer
modules. Add constants for file format layout and comprehensive test
suite
for roundtrip verification.

1 files changed, 23 insertions, 26 deletions

diff --git a/systems/sheet/macros/src/lib.rs b/systems/sheet/macros/src/lib.rs
index c0e936c..b485a82 100644
--- a/systems/sheet/macros/src/lib.rs
+++ b/systems/sheet/macros/src/lib.rs
@@ -3,9 +3,15 @@ use proc_macro2::{Span, TokenStream as TokenStream2};
 use quote::quote;
 use syn::parse_str;
 
+const INDEX_SOURCE_BUF: &str =
+    "just_enough_vcs::system::sheet_system::index_source::IndexSourceBuf";
+const INDEX_SOURCE: &str = "just_enough_vcs::system::sheet_system::index_source::IndexSource";
+
 const LOCAL_MAPPING_PATH: &str = "just_enough_vcs::system::sheet_system::mapping::LocalMapping";
+
 const MAPPING_BUF_PATH: &str = "just_enough_vcs::system::sheet_system::mapping::MappingBuf";
 const MAPPING_PATH: &str = "just_enough_vcs::system::sheet_system::mapping::Mapping";
+
 const LOCAL_MAPPING_FORWARD_PATH: &str =
     "just_enough_vcs::system::sheet_system::mapping::LocalMappingForward";
 
@@ -115,13 +121,14 @@ pub fn mapping_buf(input: TokenStream) -> TokenStream {
 
     let mapping_buf_path: syn::Path =
         parse_str(MAPPING_BUF_PATH).expect("Failed to parse MAPPING_BUF_PATH");
+    let index_source_buf_path: syn::Path =
+        parse_str(INDEX_SOURCE_BUF).expect("Failed to parse INDEX_SOURCE_BUF");
 
     let expanded = quote! {
         #mapping_buf_path::new(
             #sheet.to_string(),
             #path_vec_tokens,
-            #id.to_string(),
-            #ver.to_string()
+            #index_source_buf_path::new(#id.to_string(), #ver.to_string())
         )
     };
 
@@ -135,7 +142,7 @@ pub fn mapping_buf(input: TokenStream) -> TokenStream {
 /// let mapping = mapping!(
 ///     // Map the `version` of index `index_id`
 ///     // to `your_dir/your_file.suffix` in `your_sheet`
-///     "your_sheet:/your_dir/your_file.suffix" => "index_id/version"
+///     "your_sheet:/your_dir/your_file.suffix" => "id/ver"
 /// );
 /// ```
 #[proc_macro]
@@ -176,13 +183,14 @@ pub fn mapping(input: TokenStream) -> TokenStream {
     let path = path_vec.join("/");
 
     let mapping_path: syn::Path = parse_str(MAPPING_PATH).expect("Failed to parse MAPPING_PATH");
+    let index_source_path: syn::Path =
+        parse_str(INDEX_SOURCE).expect("Failed to parse INDEX_SOURCE");
 
     let expanded = quote! {
         #mapping_path::new(
             #sheet,
             #path,
-            #id,
-            #ver
+            #index_source_path::new(#id, #ver)
         )
     };
 
@@ -305,21 +313,22 @@ pub fn local_mapping(input: TokenStream) -> TokenStream {
         Err(err) => return err.to_compile_error().into(),
     };
 
+    let local_mapping_path: syn::Path =
+        parse_str(LOCAL_MAPPING_PATH).expect("Failed to parse LOCAL_MAPPING_PATH");
+    let local_mapping_forward_path: syn::Path =
+        parse_str(LOCAL_MAPPING_FORWARD_PATH).expect("Failed to parse LOCAL_MAPPING_FORWARD_PATH");
+    let index_source_buf_path: syn::Path =
+        parse_str(INDEX_SOURCE_BUF).expect("Failed to parse INDEX_SOURCE_BUF");
+
     match parts {
         LocalMappingParts::Latest(path_str, id, ver) => {
             let path_vec = parse_path_string(&path_str);
             let path_vec_tokens = path_vec_to_tokens(&path_vec);
 
-            let local_mapping_path: syn::Path =
-                parse_str(LOCAL_MAPPING_PATH).expect("Failed to parse LOCAL_MAPPING_PATH");
-            let local_mapping_forward_path: syn::Path = parse_str(LOCAL_MAPPING_FORWARD_PATH)
-                .expect("Failed to parse LOCAL_MAPPING_FORWARD_PATH");
-
             let expanded = quote! {
                 #local_mapping_path::new(
                     #path_vec_tokens,
-                    #id.to_string(),
-                    #ver.to_string(),
+                    #index_source_buf_path::new(#id.to_string(), #ver.to_string()),
                     #local_mapping_forward_path::Latest
                 )
             };
@@ -330,16 +339,10 @@ pub fn local_mapping(input: TokenStream) -> TokenStream {
             let path_vec = parse_path_string(&path_str);
             let path_vec_tokens = path_vec_to_tokens(&path_vec);
 
-            let local_mapping_path: syn::Path =
-                parse_str(LOCAL_MAPPING_PATH).expect("Failed to parse LOCAL_MAPPING_PATH");
-            let local_mapping_forward_path: syn::Path = parse_str(LOCAL_MAPPING_FORWARD_PATH)
-                .expect("Failed to parse LOCAL_MAPPING_FORWARD_PATH");
-
             let expanded = quote! {
                 #local_mapping_path::new(
                     #path_vec_tokens,
-                    #id.to_string(),
-                    #ver.to_string(),
+                    #index_source_buf_path::new(#id.to_string(), #ver.to_string()),
                     #local_mapping_forward_path::Version {
                         version_name: #ver.to_string()
                     }
@@ -352,16 +355,10 @@ pub fn local_mapping(input: TokenStream) -> TokenStream {
             let path_vec = parse_path_string(&path_str);
             let path_vec_tokens = path_vec_to_tokens(&path_vec);
 
-            let local_mapping_path: syn::Path =
-                parse_str(LOCAL_MAPPING_PATH).expect("Failed to parse LOCAL_MAPPING_PATH");
-            let local_mapping_forward_path: syn::Path = parse_str(LOCAL_MAPPING_FORWARD_PATH)
-                .expect("Failed to parse LOCAL_MAPPING_FORWARD_PATH");
-
             let expanded = quote! {
                 #local_mapping_path::new(
                     #path_vec_tokens,
-                    #id.to_string(),
-                    #ver.to_string(),
+                    #index_source_buf_path::new(#id.to_string(), #ver.to_string()),
                     #local_mapping_forward_path::Ref {
                         sheet_name: #ref_name.to_string()
                     }