Move std-rfc into Nushell (#15042)

Move `std-rfc` into Nushell.  `use std-rfc/<submodule>` now works "out-of-the-box"

crates/nu-std/src/lib.rs

@@ -1,11 +1,9 @@
 #![doc = include_str!("../README.md")]
 use log::trace;
-use nu_engine::eval_block;
 use nu_parser::parse;
 use nu_protocol::{
-    debugger::WithoutDebug,
-    engine::{FileStack, Stack, StateWorkingSet, VirtualPath},
-    report_parse_error, PipelineData, VirtualPathId,
+    engine::{FileStack, StateWorkingSet, VirtualPath},
+    report_parse_error, VirtualPathId,
 };
 use std::path::PathBuf;
 
@@ -22,6 +20,7 @@ pub fn load_standard_library(
     trace!("load_standard_library");
 
     let mut working_set = StateWorkingSet::new(engine_state);
+
     // Contents of the std virtual directory
     let mut std_virt_paths = vec![];
 
@@ -81,8 +80,70 @@ pub fn load_standard_library(
     let std_dir = PathBuf::from("std").to_string_lossy().to_string();
     let _ = working_set.add_virtual_path(std_dir, VirtualPath::Dir(std_virt_paths));
 
+    // Add std-rfc files
+    let mut std_rfc_virt_paths = vec![];
+
+    // std-rfc/mod.nu
+    let std_rfc_mod_virt_file_id = create_virt_file(
+        &mut working_set,
+        "std-rfc/mod.nu",
+        include_str!("../std-rfc/mod.nu"),
+    );
+    std_rfc_virt_paths.push(std_rfc_mod_virt_file_id);
+
+    // Submodules/subdirectories ... std-rfc/<module>/mod.nu
+    let mut std_rfc_submodules = vec![
+        (
+            "mod.nu",
+            "std-rfc/clip",
+            include_str!("../std-rfc/clip/mod.nu"),
+        ),
+        (
+            "mod.nu",
+            "std-rfc/conversions",
+            include_str!("../std-rfc/conversions/mod.nu"),
+        ),
+        #[cfg(feature = "sqlite")]
+        ("mod.nu", "std-rfc/kv", include_str!("../std-rfc/kv/mod.nu")),
+        (
+            "mod.nu",
+            "std-rfc/path",
+            include_str!("../std-rfc/path/mod.nu"),
+        ),
+        (
+            "mod.nu",
+            "std-rfc/str",
+            include_str!("../std-rfc/str/mod.nu"),
+        ),
+        (
+            "mod.nu",
+            "std-rfc/tables",
+            include_str!("../std-rfc/tables/mod.nu"),
+        ),
+    ];
+
+    for (filename, std_rfc_subdir_name, content) in std_rfc_submodules.drain(..) {
+        let mod_dir = PathBuf::from(std_rfc_subdir_name);
+        let name = mod_dir.join(filename);
+        let virt_file_id = create_virt_file(&mut working_set, &name.to_string_lossy(), content);
+
+        // Place file in virtual subdir
+        let mod_dir_filelist = vec![virt_file_id];
+
+        let virt_dir_id = working_set.add_virtual_path(
+            mod_dir.to_string_lossy().to_string(),
+            VirtualPath::Dir(mod_dir_filelist),
+        );
+        // Add the subdir to the list of paths in std
+        std_rfc_virt_paths.push(virt_dir_id);
+    }
+
+    // Create std virtual dir with all subdirs and files
+    let std_rfc_dir = PathBuf::from("std-rfc").to_string_lossy().to_string();
+    let _ = working_set.add_virtual_path(std_rfc_dir, VirtualPath::Dir(std_rfc_virt_paths));
+
     // Load prelude
-    let (block, delta) = {
+    let (_, delta) = {
         let source = r#"
 # Prelude
 use std/prelude *
@@ -95,7 +156,7 @@ use std/prelude *
 
         let block = parse(
             &mut working_set,
-            Some("loading stdlib"),
+            Some("loading stdlib prelude"),
             source.as_bytes(),
             false,
         );
@@ -112,13 +173,5 @@ use std/prelude *
 
     engine_state.merge_delta(delta)?;
 
-    // We need to evaluate the module in order to run the `export-env` blocks.
-    let mut stack = Stack::new();
-    let pipeline_data = PipelineData::Empty;
-
-    eval_block::<WithoutDebug>(engine_state, &mut stack, &block, pipeline_data)?;
-
-    engine_state.merge_env(&mut stack)?;
-
     Ok(())
 }