Improves startup time when using std-lib

crates/nu-cli/src/repl.rs

@@ -163,7 +163,7 @@ pub fn evaluate_repl(
         eval_source(
             engine_state,
             &mut unique_stack,
-            r#"use std banner; banner"#.as_bytes(),
+            r#"banner"#.as_bytes(),
             "show_banner",
             PipelineData::empty(),
             false,

crates/nu-std/src/lib.rs

@@ -9,20 +9,16 @@ use nu_protocol::{
 };
 use std::path::PathBuf;
 
-// Virtual std directory unlikely to appear in user's file system
-const NU_STDLIB_VIRTUAL_DIR: &str = "NU_STDLIB_VIRTUAL_DIR";
-
 pub fn load_standard_library(
     engine_state: &mut nu_protocol::engine::EngineState,
 ) -> Result<(), miette::ErrReport> {
     trace!("load_standard_library");
     let (block, delta) = {
-        // Using full virtual path to avoid potential conflicts with user having 'std' directory
+        let std_dir = PathBuf::from("std");
-        // in their working directory.
-        let std_dir = PathBuf::from(NU_STDLIB_VIRTUAL_DIR).join("std");
 
         let mut std_files = vec![
             ("mod.nu", include_str!("../std/mod.nu")),
+            ("core.nu", include_str!("../std/core.nu")),
             ("dirs.nu", include_str!("../std/dirs.nu")),
             ("dt.nu", include_str!("../std/dt.nu")),
             ("help.nu", include_str!("../std/help.nu")),
@@ -52,26 +48,15 @@ pub fn load_standard_library(
 
         let std_dir = std_dir.to_string_lossy().to_string();
         let source = r#"
-# Define the `std` module
-module std
-
 # Prelude
-use std dirs [
+use std/core.nu *
-    enter
-    shells
-    g
-    n
-    p
-    dexit
-]
-use std pwd
 "#;
 
         let _ = working_set.add_virtual_path(std_dir, VirtualPath::Dir(std_virt_paths));
 
         // Add a placeholder file to the stack of files being evaluated.
         // The name of this file doesn't matter; it's only there to set the current working directory to NU_STDLIB_VIRTUAL_DIR.
-        let placeholder = PathBuf::from(NU_STDLIB_VIRTUAL_DIR).join("loading stdlib");
+        let placeholder = PathBuf::from("loading stdlib");
         working_set.files = FileStack::with_file(placeholder);
 
         let block = parse(

crates/nu-std/std/core.nu

@@ -0,0 +1,33 @@
+use dt.nu [datetime-diff, pretty-print-duration]
+
+# Print a banner for nushell with information about the project
+export def banner [] {
+let dt = (datetime-diff (date now) 2019-05-10T09:59:12-07:00)
+$"(ansi green)     __  ,(ansi reset)
+(ansi green) .--\(\)°'.' (ansi reset)Welcome to (ansi green)Nushell(ansi reset),
+(ansi green)'|, . ,'   (ansi reset)based on the (ansi green)nu(ansi reset) language,
+(ansi green) !_-\(_\\    (ansi reset)where all data is structured!
+
+Please join our (ansi purple)Discord(ansi reset) community at (ansi purple)https://discord.gg/NtAbbGn(ansi reset)
+Our (ansi green_bold)GitHub(ansi reset) repository is at (ansi green_bold)https://github.com/nushell/nushell(ansi reset)
+Our (ansi green)Documentation(ansi reset) is located at (ansi green)https://nushell.sh(ansi reset)
+(ansi cyan)Tweet(ansi reset) us at (ansi cyan_bold)@nu_shell(ansi reset)
+Learn how to remove this at: (ansi green)https://nushell.sh/book/configuration.html#remove-welcome-message(ansi reset)
+
+It's been this long since (ansi green)Nushell(ansi reset)'s first commit:
+(pretty-print-duration $dt)
+
+Startup Time: ($nu.startup-time)
+"
+}
+
+# Return the current working directory
+export def pwd [
+    --physical (-P) # resolve symbolic links
+] {
+    if $physical {
+        $env.PWD | path expand
+    } else {
+        $env.PWD
+    }
+}

crates/nu-std/std/mod.nu

@@ -1,5 +1,6 @@
 # std.nu, `used` to load all standard library components
 
+export module core.nu
 export module assert.nu
 export module dirs.nu
 export module dt.nu
@@ -15,8 +16,6 @@ export-env {
     use log.nu []
 }
 
-use dt.nu [datetime-diff, pretty-print-duration]
-
 # Add the given paths to the PATH.
 #
 # # Example
@@ -160,27 +159,6 @@ export def bench [
     }
 }
 
-# Print a banner for nushell with information about the project
-export def banner [] {
-let dt = (datetime-diff (date now) 2019-05-10T09:59:12-07:00)
-$"(ansi green)     __  ,(ansi reset)
-(ansi green) .--\(\)°'.' (ansi reset)Welcome to (ansi green)Nushell(ansi reset),
-(ansi green)'|, . ,'   (ansi reset)based on the (ansi green)nu(ansi reset) language,
-(ansi green) !_-\(_\\    (ansi reset)where all data is structured!
-
-Please join our (ansi purple)Discord(ansi reset) community at (ansi purple)https://discord.gg/NtAbbGn(ansi reset)
-Our (ansi green_bold)GitHub(ansi reset) repository is at (ansi green_bold)https://github.com/nushell/nushell(ansi reset)
-Our (ansi green)Documentation(ansi reset) is located at (ansi green)https://nushell.sh(ansi reset)
-(ansi cyan)Tweet(ansi reset) us at (ansi cyan_bold)@nu_shell(ansi reset)
-Learn how to remove this at: (ansi green)https://nushell.sh/book/configuration.html#remove-welcome-message(ansi reset)
-
-It's been this long since (ansi green)Nushell(ansi reset)'s first commit:
-(pretty-print-duration $dt)
-
-Startup Time: ($nu.startup-time)
-"
-}
-
 # the cute and friendly mascot of Nushell :)
 export def ellie [] {
     let ellie = [
@@ -193,17 +171,6 @@ export def ellie [] {
     $ellie | str join "\n" | $"(ansi green)($in)(ansi reset)"
 }
 
-# Return the current working directory
-export def pwd [
-    --physical (-P) # resolve symbolic links
-] {
-    if $physical {
-        $env.PWD | path expand
-    } else {
-        $env.PWD
-    }
-}
-
 # repeat anything a bunch of times, yielding a list of *n* times the input
 #
 # # Examples

crates/nu-std/tests/test_core.nu

@@ -0,0 +1,7 @@
+use std assert
+
+#[test]
+def banner [] {
+    use std core
+    assert ((core banner | lines | length) == 15)
+}

crates/nu-std/tests/test_dirs.nu

@@ -1,5 +1,4 @@
 use std assert
-use std assert
 use std log
 
 # A couple of nuances to understand when testing module that exports environment:

crates/nu-std/tests/test_std.nu

@@ -70,11 +70,6 @@ def path_add_expand [] {
     rm $real_dir $link_dir
 }
 
-#[test]
-def banner [] {
-    std assert ((std banner | lines | length) == 15)
-}
-
 #[test]
 def repeat_things [] {
     std assert error { "foo" | std repeat -1 }

tests/repl/test_stdlib.rs

@@ -1,15 +1,5 @@
 use crate::repl::tests::{fail_test, run_test_std, TestResult};
 
-#[test]
-fn library_loaded() -> TestResult {
-    run_test_std("scope modules | where name == 'std' | length", "1")
-}
-
-#[test]
-fn prelude_loaded() -> TestResult {
-    run_test_std("shells | length", "1")
-}
-
 #[test]
 fn not_loaded() -> TestResult {
     fail_test("log info", "")